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* Merge branch 'android-4.4-p' of ↵Michael Bestas2021-03-17
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | https://android.googlesource.com/kernel/common into lineage-18.1-caf-msm8998 This brings LA.UM.9.2.r1-02700-SDMxx0.0 up to date with https://android.googlesource.com/kernel/common/ android-4.4-p at commit: 58bc8e0469d08 Merge 4.4.261 into android-4.4-p Conflicts: drivers/block/zram/zram_drv.c drivers/block/zram/zram_drv.h mm/zsmalloc.c Change-Id: I451bffa685eaaea04938bc6d0b8e3f4bb0f869e9
| * zsmalloc: account the number of compacted pages correctlyRokudo Yan2021-03-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 2395928158059b8f9858365fce7713ce7fef62e4 upstream. There exists multiple path may do zram compaction concurrently. 1. auto-compaction triggered during memory reclaim 2. userspace utils write zram<id>/compaction node So, multiple threads may call zs_shrinker_scan/zs_compact concurrently. But pages_compacted is a per zsmalloc pool variable and modification of the variable is not serialized(through under class->lock). There are two issues here: 1. the pages_compacted may not equal to total number of pages freed(due to concurrently add). 2. zs_shrinker_scan may not return the correct number of pages freed(issued by current shrinker). The fix is simple: 1. account the number of pages freed in zs_compact locally. 2. use actomic variable pages_compacted to accumulate total number. Link: https://lkml.kernel.org/r/20210202122235.26885-1-wu-yan@tcl.com Fixes: 860c707dca155a56 ("zsmalloc: account the number of compacted pages") Signed-off-by: Rokudo Yan <wu-yan@tcl.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | UPSTREAM: mm/zsmalloc.c: change stat type parameter to intMatthias Kaehlcke2020-02-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | zs_stat_inc/dec/get() uses enum zs_stat_type for the stat type, however some callers pass an enum fullness_group value. Change the type to int to reflect the actual use of the functions and get rid of 'enum-conversion' warnings Link: http://lkml.kernel.org/r/20170731175000.56538-1-mka@chromium.org Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Doug Anderson <dianders@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://git.kernel.org/linus/3eb95feac113d8ebad5b7b5189a65efcbd95a749 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
* | UPSTREAM: mm/zsmalloc.c: fix -Wunneeded-internal-declaration warningNick Desaulniers2020-02-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | is_first_page() is only called from the macro VM_BUG_ON_PAGE() which is only compiled in as a runtime check when CONFIG_DEBUG_VM is set, otherwise is checked at compile time and not actually compiled in. Fixes the following warning, found with Clang: mm/zsmalloc.c:472:12: warning: function 'is_first_page' is not needed and will not be emitted [-Wunneeded-internal-declaration] static int is_first_page(struct page *page) ^ Link: http://lkml.kernel.org/r/20170524053859.29059-1-nick.desaulniers@gmail.com Signed-off-by: Nick Desaulniers <nick.desaulniers@gmail.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://git.kernel.org/linus/3457f4147675108aa83f9f33c136f06bb9f8518f Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
* | Merge android-4.4.154 (d762e28) into msm-4.4Srinivasarao P2018-09-12
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * refs/heads/tmp-d762e28 Linux 4.4.154 cdrom: Fix info leak/OOB read in cdrom_ioctl_drive_status iscsi target: fix session creation failure handling scsi: core: Avoid that SCSI device removal through sysfs triggers a deadlock scsi: sysfs: Introduce sysfs_{un,}break_active_protection() MIPS: lib: Provide MIPS64r6 __multi3() for GCC < 7 MIPS: Correct the 64-bit DSP accumulator register size kprobes: Make list and blacklist root user read only s390/pci: fix out of bounds access during irq setup s390/qdio: reset old sbal_state flags s390: fix br_r1_trampoline for machines without exrl x86/spectre: Add missing family 6 check to microcode check x86/irqflags: Mark native_restore_fl extern inline pinctrl: freescale: off by one in imx1_pinconf_group_dbg_show() ASoC: sirf: Fix potential NULL pointer dereference ASoC: dpcm: don't merge format from invalid codec dai udl-kms: fix crash due to uninitialized memory udl-kms: handle allocation failure udl-kms: change down_interruptible to down fuse: Add missed unlock_page() to fuse_readpages_fill() fuse: Fix oops at process_init_reply() fuse: umount should wait for all requests fuse: fix unlocked access to processing queue fuse: fix double request_end() fuse: Don't access pipe->buffers without pipe_lock() x86/process: Re-export start_thread() x86/speculation/l1tf: Suggest what to do on systems with too much RAM x86/speculation/l1tf: Fix off-by-one error when warning that system has too much RAM x86/speculation/l1tf: Fix overflow in l1tf_pfn_limit() on 32bit KVM: arm/arm64: Skip updating PMD entry if no change KVM: arm/arm64: Skip updating PTE entry if no change arm64: mm: check for upper PAGE_SHIFT bits in pfn_valid() ext4: reset error code in ext4_find_entry in fallback ext4: sysfs: print ext4_super_block fields as little-endian ext4: check for NUL characters in extended attribute's name s390/kvm: fix deadlock when killed by oom btrfs: don't leak ret from do_chunk_alloc smb3: don't request leases in symlink creation and query smb3: Do not send SMB3 SET_INFO if nothing changed cifs: check kmalloc before use cifs: add missing debug entries for kconfig options mm/memory.c: check return value of ioremap_prot scsi: vmw_pvscsi: Return DID_RESET for status SAM_STAT_COMMAND_TERMINATED scsi: fcoe: drop frames in ELS LOGO error path drivers: net: lmc: fix case value for target abort error arc: fix type warnings in arc/mm/cache.c arc: fix build errors in arc/include/asm/delay.h enic: handle mtu change for vf properly Revert "MIPS: BCM47XX: Enable 74K Core ExternalSync for PCIe erratum" tools/power turbostat: Read extended processor family from CPUID zswap: re-check zswap_is_full() after do zswap_shrink() selftests/ftrace: Add snapshot and tracing_on test case cachefiles: Wait rather than BUG'ing on "Unexpected object collision" cachefiles: Fix refcounting bug in backing-file read monitoring fscache: Allow cancelled operations to be enqueued net: axienet: Fix double deregister of mdio bnx2x: Fix invalid memory access in rss hash config path. media: staging: omap4iss: Include asm/cacheflush.h after generic includes i2c: davinci: Avoid zero value of CLKH can: mpc5xxx_can: check of_iomap return before use net: prevent ISA drivers from building on PPC32 atl1c: reserve min skb headroom qed: Fix possible race for the link state value. net: caif: Add a missing rcu_read_unlock() in caif_flow_cb tools/power turbostat: fix -S on UP systems usb: gadget: f_uac2: fix endianness of 'struct cntrl_*_lay3' tools: usb: ffs-test: Fix build on big endian systems usb/phy: fix PPC64 build errors in phy-fsl-usb.c usb: gadget: r8a66597: Fix a possible sleep-in-atomic-context bugs in r8a66597_queue() usb: gadget: r8a66597: Fix two possible sleep-in-atomic-context bugs in init_controller() drm/imx: imx-ldb: check if channel is enabled before printing warning drm/imx: imx-ldb: disable LDB on driver bind scsi: libiscsi: fix possible NULL pointer dereference in case of TMF drm/bridge: adv7511: Reset registers on hotplug nl80211: Add a missing break in parse_station_flags mac80211: add stations tied to AP_VLANs during hw reconfig xfrm: free skb if nlsk pointer is NULL xfrm: fix missing dst_release() after policy blocking lbcast and multicast vti6: fix PMTU caching and reporting on xmit Cipso: cipso_v4_optptr enter infinite loop sched/sysctl: Check user input value of sysctl_sched_time_avg BACKPORT: zram: drop max_zpage_size and use zs_huge_class_size() BACKPORT: zsmalloc: introduce zs_huge_class_size() ANDROID: tracing: fix race condition reading saved tgids Conflicts: mm/zsmalloc.c Change-Id: I1add2f0311c887c135ddc6160963702beeb7bb88 Signed-off-by: Srinivasarao P <spathi@codeaurora.org>
| * | BACKPORT: zsmalloc: introduce zs_huge_class_size()Sergey Senozhatsky2018-08-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "zsmalloc/zram: drop zram's max_zpage_size", v3. ZRAM's max_zpage_size is a bad thing. It forces zsmalloc to store normal objects as huge ones, which results in bigger zsmalloc memory usage. Drop it and use actual zsmalloc huge-class value when decide if the object is huge or not. This patch (of 2): Not every object can be share its zspage with other objects, e.g. when the object is as big as zspage or nearly as big a zspage. For such objects zsmalloc has a so called huge class - every object which belongs to huge class consumes the entire zspage (which consists of a physical page). On x86_64, PAGE_SHIFT 12 box, the first non-huge class size is 3264, so starting down from size 3264, objects can share page(-s) and thus minimize memory wastage. ZRAM, however, has its own statically defined watermark for huge objects, namely "3 * PAGE_SIZE / 4 = 3072", and forcibly stores every object larger than this watermark (3072) as a PAGE_SIZE object, in other words, to a huge class, while zsmalloc can keep some of those objects in non-huge classes. This results in increased memory consumption. zsmalloc knows better if the object is huge or not. Introduce zs_huge_class_size() function which tells if the given object can be stored in one of non-huge classes or not. This will let us to drop ZRAM's huge object watermark and fully rely on zsmalloc when we decide if the object is huge. [sergey.senozhatsky.work@gmail.com: add pool param to zs_huge_class_size()] Link: http://lkml.kernel.org/r/20180314081833.1096-2-sergey.senozhatsky@gmail.com Link: http://lkml.kernel.org/r/20180306070639.7389-2-sergey.senozhatsky@gmail.com Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> (cherry picked from commit 010b495e2fa32353d0ef6aa70a8169e5ef617a15) Signed-off-by: Peter Kalauskas <peskal@google.com> Bug: 113183619 Change-Id: Ic35f8c1ec75f0b78bf2d83729b6aedd2999f25c8
| * | BACKPORT: zsmalloc: require GFP in zs_malloc()Sergey Senozhatsky2018-08-23
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pass GFP flags to zs_malloc() instead of using a fixed mask supplied to zs_create_pool(), so we can be more flexible, but, more importantly, we need this to switch zram to per-cpu compression streams -- zram will try to allocate handle with preemption disabled in a fast path and switch to a slow path (using different gfp mask) if the fast one has failed. Apart from that, this also align zs_malloc() interface with zspool/zbud. [sergey.senozhatsky@gmail.com: pass GFP flags to zs_malloc() instead of using a fixed mask] Link: http://lkml.kernel.org/r/20160429150942.GA637@swordfish Link: http://lkml.kernel.org/r/20160429150942.GA637@swordfish Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> (cherry picked from commit d0d8da2dc49dfdfe1d788eaf4d55eb5d4964d926) Signed-off-by: Peter Kalauskas <peskal@google.com> Bug: 112488418 Change-Id: I31276c9351be21a4ed588681b332e98142b76526
* | mm: fix build warnings in <linux/compaction.h>Minchan Kim2017-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Randy reported below build error. > In file included from ../include/linux/balloon_compaction.h:48:0, > from ../mm/balloon_compaction.c:11: > ../include/linux/compaction.h:237:51: warning: 'struct node' declared inside parameter list [enabled by default] > static inline int compaction_register_node(struct node *node) > ../include/linux/compaction.h:237:51: warning: its scope is only this definition or declaration, which is probably not what you want [enabled by default] > ../include/linux/compaction.h:242:54: warning: 'struct node' declared inside parameter list [enabled by default] > static inline void compaction_unregister_node(struct node *node) > It was caused by non-lru page migration which needs compaction.h but compaction.h doesn't include any header to be standalone. I think proper header for non-lru page migration is migrate.h rather than compaction.h because migrate.h has already headers needed to work non-lru page migration indirectly like isolate_mode_t, migrate_mode MIGRATEPAGE_SUCCESS. [akpm@linux-foundation.org: revert mm-balloon-use-general-non-lru-movable-page-feature-fix.patch temp fix] Link: http://lkml.kernel.org/r/20160610003304.GE29779@bbox Signed-off-by: Minchan Kim <minchan@kernel.org> Reported-by: Randy Dunlap <rdunlap@infradead.org> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Gioh Kim <gi-oh.kim@profitbricks.com> Cc: Rafael Aquini <aquini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Git-commit: dd4123f324bbaec7618b677b7bce2b11aee9594e Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Change-Id: If9a33a471f69bf008f4c2d40f21ff30abce200bb Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* | zsmalloc: page migration supportMinchan Kim2017-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces run-time migration feature for zspage. For migration, VM uses page.lru field so it would be better to not use page.next field which is unified with page.lru for own purpose. For that, firstly, we can get first object offset of the page via runtime calculation instead of using page.index so we can use page.index as link for page chaining instead of page.next. In case of huge object, it stores handle to page.index instead of next link of page chaining because huge object doesn't need to next link for page chaining. So get_next_page need to identify huge object to return NULL. For it, this patch uses PG_owner_priv_1 flag of the page flag. For migration, it supports three functions * zs_page_isolate It isolates a zspage which includes a subpage VM want to migrate from class so anyone cannot allocate new object from the zspage. We could try to isolate a zspage by the number of subpage so subsequent isolation trial of other subpage of the zpsage shouldn't fail. For that, we introduce zspage.isolated count. With that, zs_page_isolate can know whether zspage is already isolated or not for migration so if it is isolated for migration, subsequent isolation trial can be successful without trying further isolation. * zs_page_migrate First of all, it holds write-side zspage->lock to prevent migrate other subpage in zspage. Then, lock all objects in the page VM want to migrate. The reason we should lock all objects in the page is due to race between zs_map_object and zs_page_migrate. zs_map_object zs_page_migrate pin_tag(handle) obj = handle_to_obj(handle) obj_to_location(obj, &page, &obj_idx); write_lock(&zspage->lock) if (!trypin_tag(handle)) goto unpin_object zspage = get_zspage(page); read_lock(&zspage->lock); If zs_page_migrate doesn't do trypin_tag, zs_map_object's page can be stale by migration so it goes crash. If it locks all of objects successfully, it copies content from old page to new one, finally, create new zspage chain with new page. And if it's last isolated subpage in the zspage, put the zspage back to class. * zs_page_putback It returns isolated zspage to right fullness_group list if it fails to migrate a page. If it find a zspage is ZS_EMPTY, it queues zspage freeing to workqueue. See below about async zspage freeing. This patch introduces asynchronous zspage free. The reason to need it is we need page_lock to clear PG_movable but unfortunately, zs_free path should be atomic so the apporach is try to grab page_lock. If it got page_lock of all of pages successfully, it can free zspage immediately. Otherwise, it queues free request and free zspage via workqueue in process context. If zs_free finds the zspage is isolated when it try to free zspage, it delays the freeing until zs_page_putback finds it so it will free free the zspage finally. In this patch, we expand fullness_list from ZS_EMPTY to ZS_FULL. First of all, it will use ZS_EMPTY list for delay freeing. And with adding ZS_FULL list, it makes to identify whether zspage is isolated or not via list_empty(&zspage->list) test. [minchan@kernel.org: zsmalloc: keep first object offset in struct page] Link: http://lkml.kernel.org/r/1465788015-23195-1-git-send-email-minchan@kernel.org [minchan@kernel.org: zsmalloc: zspage sanity check] Link: http://lkml.kernel.org/r/20160603010129.GC3304@bbox Link: http://lkml.kernel.org/r/1464736881-24886-12-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Git-commit: 48b4800a1c6af2cdda344ea4e2c843dcc1f6afc9 Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Change-Id: Iee2c3448872d258d5bed71fe4c0870ba186f0d05 Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* | zsmalloc: use freeobj for indexMinchan Kim2017-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Zsmalloc stores first free object's <PFN, obj_idx> position into freeobj in each zspage. If we change it with index from first_page instead of position, it makes page migration simple because we don't need to correct other entries for linked list if a page is migrated out. Link: http://lkml.kernel.org/r/1464736881-24886-11-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Git-commit: bfd093f5e7f09c1e41c43e7605893069975cd734 Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Change-Id: I435ac58d8a87767e884901397358f4a8253ae163 Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* | zsmalloc: separate free_zspage from putback_zspageMinchan Kim2017-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, putback_zspage does free zspage under class->lock if fullness become ZS_EMPTY but it makes trouble to implement locking scheme for new zspage migration. So, this patch is to separate free_zspage from putback_zspage and free zspage out of class->lock which is preparation for zspage migration. Link: http://lkml.kernel.org/r/1464736881-24886-10-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Git-commit: 4aa409cab7c39c90f4b725ff22f52bbf5d2fc4e0 Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Change-Id: I5cb0c37206d1bb7ceb0a362733103cde335ace39 Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* | zsmalloc: introduce zspage structureMinchan Kim2017-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have squeezed meta data of zspage into first page's descriptor. So, to get meta data from subpage, we should get first page first of all. But it makes trouble to implment page migration feature of zsmalloc because any place where to get first page from subpage can be raced with first page migration. IOW, first page it got could be stale. For preventing it, I have tried several approahces but it made code complicated so finally, I concluded to separate metadata from first page. Of course, it consumes more memory. IOW, 16bytes per zspage on 32bit at the moment. It means we lost 1% at *worst case*(40B/4096B) which is not bad I think at the cost of maintenance. Link: http://lkml.kernel.org/r/1464736881-24886-9-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Git-commit: 3783689a1aa82ef27a6418b043dd7a077b8330c5 Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Change-Id: I2f0c67d7b85ebfe0655b92e13854fdbde5f26f2b Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* | zsmalloc: factor page chain functionality outMinchan Kim2017-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For page migration, we need to create page chain of zspage dynamically so this patch factors it out from alloc_zspage. Link: http://lkml.kernel.org/r/1464736881-24886-8-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Git-commit: bdb0af7ca8f0e9f4c03a9169a744b22890641b64 Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Change-Id: I6e6c925a85afb92ec2e24ea0109b9032f96fcbf0 Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* | zsmalloc: use accessorMinchan Kim2017-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Upcoming patch will change how to encode zspage meta so for easy review, this patch wraps code to access metadata as accessor. Link: http://lkml.kernel.org/r/1464736881-24886-7-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Git-commit: 4f42047bbde059823fe70381387257a9e3bd229c Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Change-Id: I972605e6a4c048dbf49ea7b52a4b2eb896a2c8d6 Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* | zsmalloc: use bit_spin_lockMinchan Kim2017-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use kernel standard bit spin-lock instead of custom mess. Even, it has a bug which doesn't disable preemption. The reason we don't have any problem is that we have used it during preemption disable section by class->lock spinlock. So no need to go to stable. Link: http://lkml.kernel.org/r/1464736881-24886-6-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Git-commit: 1b8320b620d6caa5879380f83f3884908ceedd4a Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Change-Id: I07548b9ea31f5379265217f6fa0362befc6f8663 Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* | zsmalloc: keep max_object in size_classMinchan Kim2017-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Every zspage in a size_class has same number of max objects so we could move it to a size_class. Link: http://lkml.kernel.org/r/1464736881-24886-5-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Git-commit: 1fc6e27d7b8613afe6e5c1b8cdf94339a1bce640 Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Change-Id: I45f4f956c49628cb44fdaef23c93fbe9bd2a59a4 Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* | zsmalloc: require GFP in zs_malloc()Sergey Senozhatsky2017-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pass GFP flags to zs_malloc() instead of using a fixed mask supplied to zs_create_pool(), so we can be more flexible, but, more importantly, we need this to switch zram to per-cpu compression streams -- zram will try to allocate handle with preemption disabled in a fast path and switch to a slow path (using different gfp mask) if the fast one has failed. Apart from that, this also align zs_malloc() interface with zspool/zbud. [sergey.senozhatsky@gmail.com: pass GFP flags to zs_malloc() instead of using a fixed mask] Link: http://lkml.kernel.org/r/20160429150942.GA637@swordfish Link: http://lkml.kernel.org/r/20160429150942.GA637@swordfish Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Git-commit: d0d8da2dc49dfdfe1d788eaf4d55eb5d4964d926 Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Change-Id: I61b1339bd244a3ea4e31eed893aea9a2f3ffe248 Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* | zsmalloc: remove unused pool param in obj_freeMinchan Kim2017-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | Let's remove unused pool param in obj_free Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Git-commit: 1ee4716585ed80b7917ba3c5aa38e5e0d677d583 Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Change-Id: I559b31e0a5416bda730235937387f2c7158f2959 Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* | zsmalloc: reorder function parametersMinchan Kim2017-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Clean up function parameter ordering to order higher data structure first. Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Git-commit: 251cbb951b831acd8451d75b40696834f07c29c5 Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Change-Id: Ic9d549a087415f18634d48e255d19749c735addb Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* | zsmalloc: clean up many BUG_ONMinchan Kim2017-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are many BUG_ON in zsmalloc.c which is not recommened so change them as alternatives. Normal rule is as follows: 1. avoid BUG_ON if possible. Instead, use VM_BUG_ON or VM_BUG_ON_PAGE 2. use VM_BUG_ON_PAGE if we need to see struct page's fields 3. use those assertion in primitive functions so higher functions can rely on the assertion in the primitive function. 4. Don't use assertion if following instruction can trigger Oops Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Git-commit: 830e4bc5baa9fda5d45257e9a3dbb3555c6c180e Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Change-Id: Ia4b15fb09ad5398165781861952d075665c8b8e9 Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* | zsmalloc: use first_page rather than pageMinchan Kim2017-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clean up function parameter "struct page". Many functions of zsmalloc expect that page paramter is "first_page" so use "first_page" rather than "page" for code readability. Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Git-commit: a42094676f076534bf4998625456fe0bb99c1f1e Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Change-Id: I68c0a37a1fd5c8a9f34c7e7a0d2a580c1720685d Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* | mm/zsmalloc: add `freeable' column to pool statSergey Senozhatsky2017-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new column to pool stats, which will tell how many pages ideally can be freed by class compaction, so it will be easier to analyze zsmalloc fragmentation. At the moment, we have only numbers of FULL and ALMOST_EMPTY classes, but they don't tell us how badly the class is fragmented internally. The new /sys/kernel/debug/zsmalloc/zramX/classes output look as follows: class size almost_full almost_empty obj_allocated obj_used pages_used pages_per_zspage freeable [..] 12 224 0 2 146 5 8 4 4 13 240 0 0 0 0 0 1 0 14 256 1 13 1840 1672 115 1 10 15 272 0 0 0 0 0 1 0 [..] 49 816 0 3 745 735 149 1 2 51 848 3 4 361 306 76 4 8 52 864 12 14 378 268 81 3 21 54 896 1 12 117 57 26 2 12 57 944 0 0 0 0 0 3 0 [..] Total 26 131 12709 10994 1071 134 For example, from this particular output we can easily conclude that class-896 is heavily fragmented -- it occupies 26 pages, 12 can be freed by compaction. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Git-commit: 1120ed5483941d9cd2cf52cb9644a4311dbd1011 Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Change-Id: Ib3cf57a59c3c3ec469f43f594a1b20514ea8e452 Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* | zsmalloc: drop unused member 'mapping_area->huge'YiPing Xu2017-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When unmapping a huge class page in zs_unmap_object, the page will be unmapped by kmap_atomic. the "!area->huge" branch in __zs_unmap_object is alway true, and no code set "area->huge" now, so we can drop it. Signed-off-by: YiPing Xu <xuyiping@huawei.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Git-commit: a82cbf07131b56e7e51fbb008b82ef769af08790 Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Change-Id: I332dc03f886d1e6547b0b59914046a7924405d1b Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* | zsmalloc: reorganize struct size_class to pack 4 bytes holeWeijie Yang2017-02-21
|/ | | | | | | | | | | | | | | Reoder the pages_per_zspage field in struct size_class which can eliminate the 4 bytes hole between it and stats field. Signed-off-by: Weijie Yang <weijie.yang@samsung.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Git-commit: 7dfa4612204b511c934ca2a0e4f306f9981bd9aa Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Change-Id: I82fdd68951448d78540e61f70d8d0123604d7e28 Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
* zsmalloc: fix zs_can_compact() integer overflowSergey Senozhatsky2016-05-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 44f43e99fe70833058482d183e99fdfd11220996 upstream. zs_can_compact() has two race conditions in its core calculation: unsigned long obj_wasted = zs_stat_get(class, OBJ_ALLOCATED) - zs_stat_get(class, OBJ_USED); 1) classes are not locked, so the numbers of allocated and used objects can change by the concurrent ops happening on other CPUs 2) shrinker invokes it from preemptible context Depending on the circumstances, thus, OBJ_ALLOCATED can become less than OBJ_USED, which can result in either very high or negative `total_scan' value calculated later in do_shrink_slab(). do_shrink_slab() has some logic to prevent those cases: vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-62 vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-62 vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-64 vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-62 vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-62 vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-62 However, due to the way `total_scan' is calculated, not every shrinker->count_objects() overflow can be spotted and handled. To demonstrate the latter, I added some debugging code to do_shrink_slab() (x86_64) and the results were: vmscan: OVERFLOW: shrinker->count_objects() == -1 [18446744073709551615] vmscan: but total_scan > 0: 92679974445502 vmscan: resulting total_scan: 92679974445502 [..] vmscan: OVERFLOW: shrinker->count_objects() == -1 [18446744073709551615] vmscan: but total_scan > 0: 22634041808232578 vmscan: resulting total_scan: 22634041808232578 Even though shrinker->count_objects() has returned an overflowed value, the resulting `total_scan' is positive, and, what is more worrisome, it is insanely huge. This value is getting used later on in shrinker->scan_objects() loop: while (total_scan >= batch_size || total_scan >= freeable) { unsigned long ret; unsigned long nr_to_scan = min(batch_size, total_scan); shrinkctl->nr_to_scan = nr_to_scan; ret = shrinker->scan_objects(shrinker, shrinkctl); if (ret == SHRINK_STOP) break; freed += ret; count_vm_events(SLABS_SCANNED, nr_to_scan); total_scan -= nr_to_scan; cond_resched(); } `total_scan >= batch_size' is true for a very-very long time and 'total_scan >= freeable' is also true for quite some time, because `freeable < 0' and `total_scan' is large enough, for example, 22634041808232578. The only break condition, in the given scheme of things, is shrinker->scan_objects() == SHRINK_STOP test, which is a bit too weak to rely on, especially in heavy zsmalloc-usage scenarios. To fix the issue, take a pool stat snapshot and use it instead of racy zs_stat_get() calls. Link: http://lkml.kernel.org/r/20160509140052.3389-1-sergey.senozhatsky@gmail.com Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* zsmalloc: fix migrate_zspage-zs_free race conditionJunil Lee2016-02-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit c102f07ca0b04f2cb49cfc161c83f6239d17f491 upstream. record_obj() in migrate_zspage() does not preserve handle's HANDLE_PIN_BIT, set by find_aloced_obj()->trypin_tag(), and implicitly (accidentally) un-pins the handle, while migrate_zspage() still performs an explicit unpin_tag() on the that handle. This additional explicit unpin_tag() introduces a race condition with zs_free(), which can pin that handle by this time, so the handle becomes un-pinned. Schematically, it goes like this: CPU0 CPU1 migrate_zspage find_alloced_obj trypin_tag set HANDLE_PIN_BIT zs_free() pin_tag() obj_malloc() -- new object, no tag record_obj() -- remove HANDLE_PIN_BIT set HANDLE_PIN_BIT unpin_tag() -- remove zs_free's HANDLE_PIN_BIT The race condition may result in a NULL pointer dereference: Unable to handle kernel NULL pointer dereference at virtual address 00000000 CPU: 0 PID: 19001 Comm: CookieMonsterCl Tainted: PC is at get_zspage_mapping+0x0/0x24 LR is at obj_free.isra.22+0x64/0x128 Call trace: get_zspage_mapping+0x0/0x24 zs_free+0x88/0x114 zram_free_page+0x64/0xcc zram_slot_free_notify+0x90/0x108 swap_entry_free+0x278/0x294 free_swap_and_cache+0x38/0x11c unmap_single_vma+0x480/0x5c8 unmap_vmas+0x44/0x60 exit_mmap+0x50/0x110 mmput+0x58/0xe0 do_exit+0x320/0x8dc do_group_exit+0x44/0xa8 get_signal+0x538/0x580 do_signal+0x98/0x4b8 do_notify_resume+0x14/0x5c This patch keeps the lock bit in migration path and update value atomically. Signed-off-by: Junil Lee <junil0814.lee@lge.com> Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* zsmalloc: use page->private instead of page->first_pageKirill A. Shutemov2015-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | We are going to rework how compound_head() work. It will not use page->first_page as we have it now. The only other user of page->first_page beyond compound pages is zsmalloc. Let's use page->private instead of page->first_page here. It occupies the same storage space. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: reduce size_class memory usageSergey Senozhatsky2015-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Each `struct size_class' contains `struct zs_size_stat': an array of NR_ZS_STAT_TYPE `unsigned long'. For zsmalloc built with no CONFIG_ZSMALLOC_STAT this results in a waste of `2 * sizeof(unsigned long)' per-class. The patch removes unneeded `struct zs_size_stat' members by redefining NR_ZS_STAT_TYPE (max stat idx in array). Since both NR_ZS_STAT_TYPE and zs_stat_type are compile time constants, GCC can eliminate zs_stat_inc()/zs_stat_dec() calls that use zs_stat_type larger than NR_ZS_STAT_TYPE: CLASS_ALMOST_EMPTY and CLASS_ALMOST_FULL at the moment. ./scripts/bloat-o-meter mm/zsmalloc.o.old mm/zsmalloc.o.new add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-39 (-39) function old new delta fix_fullness_group 97 94 -3 insert_zspage 100 86 -14 remove_zspage 141 119 -22 To summarize: a) each class now uses less memory b) we avoid a number of dec/inc stats (a minor optimization, but still). The gain will increase once we introduce additional stats. A simple IO test. iozone -t 4 -R -r 32K -s 60M -I +Z patched base " Initial write " 4145599.06 4127509.75 " Rewrite " 4146225.94 4223618.50 " Read " 17157606.00 17211329.50 " Re-read " 17380428.00 17267650.50 " Reverse Read " 16742768.00 16162732.75 " Stride read " 16586245.75 16073934.25 " Random read " 16349587.50 15799401.75 " Mixed workload " 10344230.62 9775551.50 " Random write " 4277700.62 4260019.69 " Pwrite " 4302049.12 4313703.88 " Pread " 6164463.16 6126536.72 " Fwrite " 7131195.00 6952586.00 " Fread " 12682602.25 12619207.50 Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/zsmalloc.c: remove useless line in obj_free()Hui Zhu2015-11-06
| | | | | | | | Signed-off-by: Hui Zhu <zhuhui@xiaomi.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: don't test shrinker_enabled in zs_shrinker_count()Sergey Senozhatsky2015-11-06
| | | | | | | | | | | We don't let user to disable shrinker in zsmalloc (once it's been enabled), so no need to check ->shrinker_enabled in zs_shrinker_count(), at the moment at least. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: use preempt.h for in_interrupt()Sergey Senozhatsky2015-11-06
| | | | | | | | | | | | | | A cosmetic change. Commit c60369f01125 ("staging: zsmalloc: prevent mappping in interrupt context") added in_interrupt() check to zs_map_object() and 'hardirq.h' include; but in_interrupt() macro is defined in 'preempt.h' not in 'hardirq.h', so include it instead. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: fix obj_to_head use page_private(page) as value but not pointerHui Zhu2015-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In obj_malloc(): if (!class->huge) /* record handle in the header of allocated chunk */ link->handle = handle; else /* record handle in first_page->private */ set_page_private(first_page, handle); In the hugepage we save handle to private directly. But in obj_to_head(): if (class->huge) { VM_BUG_ON(!is_first_page(page)); return *(unsigned long *)page_private(page); } else return *(unsigned long *)obj; It is used as a pointer. The reason why there is no problem until now is huge-class page is born with ZS_FULL so it can't be migrated. However, we need this patch for future work: "VM-aware zsmalloced page migration" to reduce external fragmentation. Signed-off-by: Hui Zhu <zhuhui@xiaomi.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: add comments for ->inuse to zspageHui Zhu2015-11-06
| | | | | | | | | | [akpm@linux-foundation.org: fix grammar] Signed-off-by: Hui Zhu <zhuhui@xiaomi.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: zsmalloc: constify struct zs_pool nameSergey SENOZHATSKY2015-11-06
| | | | | | | | | | | Constify `struct zs_pool' ->name. [akpm@inux-foundation.org: constify zpool_create_pool()'s `type' arg also] Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Dan Streetman <ddstreet@ieee.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: zpool: constify the zpool_opsKrzysztof Kozlowski2015-09-08
| | | | | | | | | | The structure zpool_ops is not modified so make the pointer to it a pointer to const. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Acked-by: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: remove null check from destroy_handle_cache()Sergey Senozhatsky2015-09-08
| | | | | | | | | | | We can pass a NULL cache pointer to kmem_cache_destroy(), because it NULL-checks its argument now. Remove redundant test from destroy_handle_cache(). Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: do not take class lock in zs_shrinker_count()Sergey Senozhatsky2015-09-08
| | | | | | | | | | | | | | | | | | | | | We can avoid taking class ->lock around zs_can_compact() in zs_shrinker_count(), because the number that we return back is outdated in general case, by design. We have different sources that are able to change class's state right after we return from zs_can_compact() -- ongoing I/O operations, manually triggered compaction, or two of them happening simultaneously. We re-do this calculations during compaction on a per class basis anyway. zs_unregister_shrinker() will not return until we have an active shrinker, so classes won't unexpectedly disappear while zs_shrinker_count() iterates them. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: use class->pages_per_zspageMinchan Kim2015-09-08
| | | | | | | | | | There is no need to recalcurate pages_per_zspage in runtime. Just use class->pages_per_zspage to avoid unnecessary runtime overhead. Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: consider ZS_ALMOST_FULL as migrate sourceMinchan Kim2015-09-08
| | | | | | | | | | | | There is no reason to prevent select ZS_ALMOST_FULL as migration source if we cannot find source from ZS_ALMOST_EMPTY. With this patch, zs_can_compact will return more exact result. Signed-off-by: Minchan Kim <minchan.kim@lge.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: partial page ordering within a fullness_listSergey Senozhatsky2015-09-08
| | | | | | | | | | | | | | | | | | | | | We want to see more ZS_FULL pages and less ZS_ALMOST_{FULL, EMPTY} pages. Put a page with higher ->inuse count first within its ->fullness_list, which will give us better chances to fill up this page with new objects (find_get_zspage() return ->fullness_list head for new object allocation), so some zspages will become ZS_ALMOST_FULL/ZS_FULL quicker. It performs a trivial and cheap ->inuse compare which does not slow down zsmalloc and in the worst case keeps the list pages in no particular order. A more expensive solution could sort fullness_list by ->inuse count. [minchan@kernel.org: code adjustments] Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: use shrinker to trigger auto-compactionSergey Senozhatsky2015-09-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Perform automatic pool compaction by a shrinker when system is getting tight on memory. User-space has a very little knowledge regarding zsmalloc fragmentation and basically has no mechanism to tell whether compaction will result in any memory gain. Another issue is that user space is not always aware of the fact that system is getting tight on memory. Which leads to very uncomfortable scenarios when user space may start issuing compaction 'randomly' or from crontab (for example). Fragmentation is not always necessarily bad, allocated and unused objects, after all, may be filled with the data later, w/o the need of allocating a new zspage. On the other hand, we obviously don't want to waste memory when the system needs it. Compaction now has a relatively quick pool scan so we are able to estimate the number of pages that will be freed easily, which makes it possible to call this function from a shrinker->count_objects() callback. We also abort compaction as soon as we detect that we can't free any pages any more, preventing wasteful objects migrations. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Suggested-by: Minchan Kim <minchan@kernel.org> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: account the number of compacted pagesSergey Senozhatsky2015-09-08
| | | | | | | | | | | | | | | | | | | | | Compaction returns back to zram the number of migrated objects, which is quite uninformative -- we have objects of different sizes so user space cannot obtain any valuable data from that number. Change compaction to operate in terms of pages and return back to compaction issuer the number of pages that were freed during compaction. So from now on we will export more meaningful value in zram<id>/mm_stat -- the number of freed (compacted) pages. This requires: (a) a rename of `num_migrated' to 'pages_compacted' (b) a internal API change -- return first_page's fullness_group from putback_zspage(), so we know when putback_zspage() did free_zspage(). It helps us to account compaction stats correctly. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc/zram: introduce zs_pool_stats apiSergey Senozhatsky2015-09-08
| | | | | | | | | | | | | | | | | | | | | | | | `zs_compact_control' accounts the number of migrated objects but it has a limited lifespan -- we lose it as soon as zs_compaction() returns back to zram. It worked fine, because (a) zram had it's own counter of migrated objects and (b) only zram could trigger compaction. However, this does not work for automatic pool compaction (not issued by zram). To account objects migrated during auto-compaction (issued by the shrinker) we need to store this number in zs_pool. Define a new `struct zs_pool_stats' structure to keep zs_pool's stats there. It provides only `num_migrated', as of this writing, but it surely can be extended. A new zsmalloc zs_pool_stats() symbol exports zs_pool's stats back to caller. Use zs_pool_stats() in zram and remove `num_migrated' from zram_stats. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Suggested-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: cosmetic compaction code adjustmentsSergey Senozhatsky2015-09-08
| | | | | | | | | | | | | | | | | Change zs_object_copy() argument order to be (DST, SRC) rather than (SRC, DST). copy/move functions usually have (to, from) arguments order. Rename alloc_target_page() to isolate_target_page(). This function doesn't allocate anything, it isolates target page, pretty much like isolate_source_page(). Tweak __zs_compact() comment. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: introduce zs_can_compact() functionSergey Senozhatsky2015-09-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This function checks if class compaction will free any pages. Rephrasing -- do we have enough unused objects to form at least one ZS_EMPTY page and free it. It aborts compaction if class compaction will not result in any (further) savings. EXAMPLE (this debug output is not part of this patch set): - class size - number of allocated objects - number of used objects - max objects per zspage - pages per zspage - estimated number of pages that will be freed [..] class-512 objs:544 inuse:540 maxobj-per-zspage:8 pages-per-zspage:1 zspages-to-free:0 ... class-512 compaction is useless. break class-496 objs:660 inuse:570 maxobj-per-zspage:33 pages-per-zspage:4 zspages-to-free:2 class-496 objs:627 inuse:570 maxobj-per-zspage:33 pages-per-zspage:4 zspages-to-free:1 class-496 objs:594 inuse:570 maxobj-per-zspage:33 pages-per-zspage:4 zspages-to-free:0 ... class-496 compaction is useless. break class-448 objs:657 inuse:617 maxobj-per-zspage:9 pages-per-zspage:1 zspages-to-free:4 class-448 objs:648 inuse:617 maxobj-per-zspage:9 pages-per-zspage:1 zspages-to-free:3 class-448 objs:639 inuse:617 maxobj-per-zspage:9 pages-per-zspage:1 zspages-to-free:2 class-448 objs:630 inuse:617 maxobj-per-zspage:9 pages-per-zspage:1 zspages-to-free:1 class-448 objs:621 inuse:617 maxobj-per-zspage:9 pages-per-zspage:1 zspages-to-free:0 ... class-448 compaction is useless. break class-432 objs:728 inuse:685 maxobj-per-zspage:28 pages-per-zspage:3 zspages-to-free:1 class-432 objs:700 inuse:685 maxobj-per-zspage:28 pages-per-zspage:3 zspages-to-free:0 ... class-432 compaction is useless. break class-416 objs:819 inuse:705 maxobj-per-zspage:39 pages-per-zspage:4 zspages-to-free:2 class-416 objs:780 inuse:705 maxobj-per-zspage:39 pages-per-zspage:4 zspages-to-free:1 class-416 objs:741 inuse:705 maxobj-per-zspage:39 pages-per-zspage:4 zspages-to-free:0 ... class-416 compaction is useless. break class-400 objs:690 inuse:674 maxobj-per-zspage:10 pages-per-zspage:1 zspages-to-free:1 class-400 objs:680 inuse:674 maxobj-per-zspage:10 pages-per-zspage:1 zspages-to-free:0 ... class-400 compaction is useless. break class-384 objs:736 inuse:709 maxobj-per-zspage:32 pages-per-zspage:3 zspages-to-free:0 ... class-384 compaction is useless. break [..] Every "compaction is useless" indicates that we saved CPU cycles. class-512 has 544 object allocated 540 objects used 8 objects per-page Even if we have a ALMOST_EMPTY zspage, we still don't have enough room to migrate all of its objects and free this zspage; so compaction will not make a lot of sense, it's better to just leave it as is. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: always keep per-class statsSergey Senozhatsky2015-09-08
| | | | | | | | | | | | | | | | | | | | | | Always account per-class `zs_size_stat' stats. This data will help us make better decisions during compaction. We are especially interested in OBJ_ALLOCATED and OBJ_USED, which can tell us if class compaction will result in any memory gain. For instance, we know the number of allocated objects in the class, the number of objects being used (so we also know how many objects are not used) and the number of objects per-page. So we can ensure if we have enough unused objects to form at least one ZS_EMPTY zspage during compaction. We calculate this value on per-class basis so we can calculate a total number of zspages that can be released. Which is exactly what a shrinker wants to know. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: drop unused variable `nr_to_migrate'Sergey Senozhatsky2015-09-08
| | | | | | | | | | | | | | | | | | | | | | | | | | This patchset tweaks compaction and makes it possible to trigger pool compaction automatically when system is getting low on memory. zsmalloc in some cases can suffer from a notable fragmentation and compaction can release some considerable amount of memory. The problem here is that currently we fully rely on user space to perform compaction when needed. However, performing zsmalloc compaction is not always an obvious thing to do. For example, suppose we have a `idle' fragmented (compaction was never performed) zram device and system is getting low on memory due to some 3rd party user processes (gcc LTO, or firefox, etc.). It's quite unlikely that user space will issue zpool compaction in this case. Besides, user space cannot tell for sure how badly pool is fragmented; however, this info is known to zsmalloc and, hence, to a shrinker. This patch (of 7): __zs_compact() does not use `nr_to_migrate', drop it. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zpool: remove zpool_evict()Dan Streetman2015-06-25
| | | | | | | | | | | | | | | | | | | | | | | Remove zpool_evict() helper function. As zbud is currently the only zpool implementation that supports eviction, add zpool and zpool_ops references to struct zbud_pool and directly call zpool_ops->evict(zpool, handle) on eviction. Currently zpool provides the zpool_evict helper which locks the zpool list lock and searches through all pools to find the specific one matching the caller, and call the corresponding zpool_ops->evict function. However, this is unnecessary, as the zbud pool can simply keep a reference to the zpool that created it, as well as the zpool_ops, and directly call the zpool_ops->evict function, when it needs to evict a page. This avoids a spinlock and list search in zpool for each eviction. Signed-off-by: Dan Streetman <ddstreet@ieee.org> Cc: Seth Jennings <sjennings@variantweb.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: remove obsolete ZSMALLOC_DEBUGMarcin Jabrzyk2015-06-25
| | | | | | | | | | | The DEBUG define in zsmalloc is useless, there is no usage of it at all. Signed-off-by: Marcin Jabrzyk <m.jabrzyk@samsung.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: fix a null pointer dereference in destroy_handle_cache()Sergey Senozhatsky2015-06-10
| | | | | | | | | | | | | If zs_create_pool()->create_handle_cache()->kmem_cache_create() or pool->name allocation fails, zs_create_pool()->destroy_handle_cache() will dereference the NULL pool->handle_cachep. Modify destroy_handle_cache() to avoid this. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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