From b416d439eca0cf42482816cdc4ef6a8ab5a5ac2e Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Sat, 21 Mar 2020 18:22:41 -0700 Subject: x86/mm: split vmalloc_sync_all() commit 763802b53a427ed3cbd419dbba255c414fdd9e7c upstream. Commit 3f8fd02b1bf1 ("mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy()") introduced a call to vmalloc_sync_all() in the vunmap() code-path. While this change was necessary to maintain correctness on x86-32-pae kernels, it also adds additional cycles for architectures that don't need it. Specifically on x86-64 with CONFIG_VMAP_STACK=y some people reported severe performance regressions in micro-benchmarks because it now also calls the x86-64 implementation of vmalloc_sync_all() on vunmap(). But the vmalloc_sync_all() implementation on x86-64 is only needed for newly created mappings. To avoid the unnecessary work on x86-64 and to gain the performance back, split up vmalloc_sync_all() into two functions: * vmalloc_sync_mappings(), and * vmalloc_sync_unmappings() Most call-sites to vmalloc_sync_all() only care about new mappings being synchronized. The only exception is the new call-site added in the above mentioned commit. Shile Zhang directed us to a report of an 80% regression in reaim throughput. Fixes: 3f8fd02b1bf1 ("mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy()") Reported-by: kernel test robot Reported-by: Shile Zhang Signed-off-by: Joerg Roedel Signed-off-by: Andrew Morton Tested-by: Borislav Petkov Acked-by: Rafael J. Wysocki [GHES] Cc: Dave Hansen Cc: Andy Lutomirski Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Link: http://lkml.kernel.org/r/20191009124418.8286-1-joro@8bytes.org Link: https://lists.01.org/hyperkitty/list/lkp@lists.01.org/thread/4D3JPPHBNOSPFK2KEPC6KGKS6J25AIDB/ Link: http://lkml.kernel.org/r/20191113095530.228959-1-shile.zhang@linux.alibaba.com Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- include/linux/vmalloc.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 3bff87a25a42..ecc63f320a54 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -92,8 +92,9 @@ extern int remap_vmalloc_range_partial(struct vm_area_struct *vma, extern int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, unsigned long pgoff); -void vmalloc_sync_all(void); - +void vmalloc_sync_mappings(void); +void vmalloc_sync_unmappings(void); + /* * Lowlevel-APIs (not for driver use!) */ -- cgit v1.2.3 From 24bbfe34bb44c036c3a0874bf74fc2387d5557bf Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 4 Mar 2020 11:28:31 +0100 Subject: futex: Fix inode life-time issue commit 8019ad13ef7f64be44d4f892af9c840179009254 upstream. As reported by Jann, ihold() does not in fact guarantee inode persistence. And instead of making it so, replace the usage of inode pointers with a per boot, machine wide, unique inode identifier. This sequence number is global, but shared (file backed) futexes are rare enough that this should not become a performance issue. Reported-by: Jann Horn Suggested-by: Linus Torvalds Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Greg Kroah-Hartman --- include/linux/fs.h | 1 + include/linux/futex.h | 17 ++++++++++------- 2 files changed, 11 insertions(+), 7 deletions(-) (limited to 'include/linux') diff --git a/include/linux/fs.h b/include/linux/fs.h index 26c4bf47cc99..e79b31f273bd 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -658,6 +658,7 @@ struct inode { struct rcu_head i_rcu; }; u64 i_version; + atomic64_t i_sequence; /* see futex */ atomic_t i_count; atomic_t i_dio_count; atomic_t i_writecount; diff --git a/include/linux/futex.h b/include/linux/futex.h index 6435f46d6e13..c015fa91e7cc 100644 --- a/include/linux/futex.h +++ b/include/linux/futex.h @@ -34,23 +34,26 @@ handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int pi); union futex_key { struct { + u64 i_seq; unsigned long pgoff; - struct inode *inode; - int offset; + unsigned int offset; } shared; struct { + union { + struct mm_struct *mm; + u64 __tmp; + }; unsigned long address; - struct mm_struct *mm; - int offset; + unsigned int offset; } private; struct { + u64 ptr; unsigned long word; - void *ptr; - int offset; + unsigned int offset; } both; }; -#define FUTEX_KEY_INIT (union futex_key) { .both = { .ptr = NULL } } +#define FUTEX_KEY_INIT (union futex_key) { .both = { .ptr = 0ULL } } #ifdef CONFIG_FUTEX extern void exit_robust_list(struct task_struct *curr); -- cgit v1.2.3 From 10f89ef408c91496ddc0b2cfa5cf9662e253a1a5 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Wed, 19 Feb 2020 08:39:43 +0100 Subject: vt: selection, introduce vc_is_sel commit dce05aa6eec977f1472abed95ccd71276b9a3864 upstream. Avoid global variables (namely sel_cons) by introducing vc_is_sel. It checks whether the parameter is the current selection console. This will help putting sel_cons to a struct later. Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20200219073951.16151-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman --- include/linux/selection.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/selection.h b/include/linux/selection.h index 85193aa8c1e3..ca3d9513b5ac 100644 --- a/include/linux/selection.h +++ b/include/linux/selection.h @@ -12,8 +12,8 @@ struct tty_struct; -extern struct vc_data *sel_cons; struct tty_struct; +struct vc_data; extern void clear_selection(void); extern int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty); @@ -22,6 +22,8 @@ extern int sel_loadlut(char __user *p); extern int mouse_reporting(void); extern void mouse_report(struct tty_struct * tty, int butt, int mrx, int mry); +bool vc_is_sel(struct vc_data *vc); + extern int console_blanked; extern unsigned char color_table[]; -- cgit v1.2.3 From 94141b4fa4a439010436f8fe64861e5e6a38dba1 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Wed, 19 Feb 2020 08:39:48 +0100 Subject: vt: switch vt_dont_switch to bool commit f400991bf872debffb01c46da882dc97d7e3248e upstream. vt_dont_switch is pure boolean, no need for whole char. Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20200219073951.16151-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman --- include/linux/vt_kern.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/vt_kern.h b/include/linux/vt_kern.h index 8d7634247fb4..c39d30db067c 100644 --- a/include/linux/vt_kern.h +++ b/include/linux/vt_kern.h @@ -142,7 +142,7 @@ static inline bool vt_force_oops_output(struct vc_data *vc) return false; } -extern char vt_dont_switch; +extern bool vt_dont_switch; extern int default_utf8; extern int global_cursor_default; -- cgit v1.2.3 From 4d1f008a610586524a93f43a7cafdff90fd3b1a8 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 14 Nov 2016 17:29:48 +0100 Subject: locking/atomic, kref: Add kref_read() commit 2c935bc57221cc2edc787c72ea0e2d30cdcd3d5e upstream. Since we need to change the implementation, stop exposing internals. Provide kref_read() to read the current reference count; typically used for debug messages. Kills two anti-patterns: atomic_read(&kref->refcount) kref->refcount.counter Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Greg Kroah-Hartman Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar [only add kref_read() to kref.h for stable backports - gregkh] Signed-off-by: Greg Kroah-Hartman --- include/linux/kref.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux') diff --git a/include/linux/kref.h b/include/linux/kref.h index e15828fd71f1..e2df6d397ff0 100644 --- a/include/linux/kref.h +++ b/include/linux/kref.h @@ -33,6 +33,11 @@ static inline void kref_init(struct kref *kref) atomic_set(&kref->refcount, 1); } +static inline int kref_read(const struct kref *kref) +{ + return atomic_read(&kref->refcount); +} + /** * kref_get - increment refcount for object. * @kref: object. -- cgit v1.2.3