From 857eceebd2803c9a3459f784acf45e5266921e4d Mon Sep 17 00:00:00 2001 From: Tim Abbott Date: Tue, 23 Jun 2009 19:59:36 -0400 Subject: Add new __init_task_data macro to be used in arch init_task.c files. This patch is preparation for replacing most ".data.init_task" in the kernel with macros, so that the section name can later be changed without having to touch a lot of the kernel. The long-term goal here is to be able to change the kernel's magic section names to those that are compatible with -ffunction-sections -fdata-sections. This requires renaming all magic sections with names of the form ".data.foo". Signed-off-by: Tim Abbott Signed-off-by: Sam Ravnborg --- include/linux/init_task.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 5368fbdc7801..7fc01b13be43 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -183,5 +183,8 @@ extern struct cred init_cred; LIST_HEAD_INIT(cpu_timers[2]), \ } +/* Attach to the init_task data structure for proper alignment */ +#define __init_task_data __attribute__((__section__(".data.init_task"))) + #endif -- cgit v1.2.3 From f41d911f8c49a5d65c86504c19e8204bb605c4fd Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sat, 22 Aug 2009 13:56:52 -0700 Subject: rcu: Merge preemptable-RCU functionality into hierarchical RCU Create a kernel/rcutree_plugin.h file that contains definitions for preemptable RCU (or, under the #else branch of the #ifdef, empty definitions for the classic non-preemptable semantics). These definitions fit into plugins defined in kernel/rcutree.c for this purpose. This variant of preemptable RCU uses a new algorithm whose read-side expense is roughly that of classic hierarchical RCU under CONFIG_PREEMPT. This new algorithm's update-side expense is similar to that of classic hierarchical RCU, and, in absence of read-side preemption or blocking, is exactly that of classic hierarchical RCU. Perhaps more important, this new algorithm has a much simpler implementation, saving well over 1,000 lines of code compared to mainline's implementation of preemptable RCU, which will hopefully be retired in favor of this new algorithm. The simplifications are obtained by maintaining per-task nesting state for running tasks, and using a simple lock-protected algorithm to handle accounting when tasks block within RCU read-side critical sections, making use of lessons learned while creating numerous user-level RCU implementations over the past 18 months. Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <12509746134003-git-send-email-> Signed-off-by: Ingo Molnar --- include/linux/init_task.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 7fc01b13be43..971a968831bf 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -94,6 +94,20 @@ extern struct group_info init_groups; # define CAP_INIT_BSET CAP_INIT_EFF_SET #endif +#ifdef CONFIG_PREEMPT_RCU +#define INIT_TASK_RCU_PREEMPT(tsk) \ + .rcu_read_lock_nesting = 0, \ + .rcu_flipctr_idx = 0, +#elif defined(CONFIG_TREE_PREEMPT_RCU) +#define INIT_TASK_RCU_PREEMPT(tsk) \ + .rcu_read_lock_nesting = 0, \ + .rcu_read_unlock_special = 0, \ + .rcu_blocked_cpu = -1, \ + .rcu_node_entry = LIST_HEAD_INIT(tsk.rcu_node_entry), +#else +#define INIT_TASK_RCU_PREEMPT(tsk) +#endif + extern struct cred init_cred; #ifdef CONFIG_PERF_COUNTERS @@ -173,6 +187,7 @@ extern struct cred init_cred; INIT_LOCKDEP \ INIT_FTRACE_GRAPH \ INIT_TRACE_RECURSION \ + INIT_TASK_RCU_PREEMPT(tsk) \ } -- cgit v1.2.3 From 6b3ef48adf847f7adf11c870e3ffacac150f1564 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sat, 22 Aug 2009 13:56:53 -0700 Subject: rcu: Remove CONFIG_PREEMPT_RCU Now that CONFIG_TREE_PREEMPT_RCU is in place, there is no further need for CONFIG_PREEMPT_RCU. Remove it, along with whatever subtle bugs it may (or may not) contain. Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <125097461396-git-send-email-> Signed-off-by: Ingo Molnar --- include/linux/init_task.h | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 971a968831bf..79d4baee31b6 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -94,11 +94,7 @@ extern struct group_info init_groups; # define CAP_INIT_BSET CAP_INIT_EFF_SET #endif -#ifdef CONFIG_PREEMPT_RCU -#define INIT_TASK_RCU_PREEMPT(tsk) \ - .rcu_read_lock_nesting = 0, \ - .rcu_flipctr_idx = 0, -#elif defined(CONFIG_TREE_PREEMPT_RCU) +#ifdef CONFIG_TREE_PREEMPT_RCU #define INIT_TASK_RCU_PREEMPT(tsk) \ .rcu_read_lock_nesting = 0, \ .rcu_read_unlock_special = 0, \ -- cgit v1.2.3 From dd5d19bafd90d33043a4a14b2e2d98612caa293c Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 27 Aug 2009 14:58:16 -0700 Subject: rcu: Create rcutree plugins to handle hotplug CPU for multi-level trees When offlining CPUs from a multi-level tree, there is the possibility of offlining the last CPU from a given node when there are preempted RCU read-side critical sections that started life on one of the CPUs on that node. In this case, the corresponding tasks will be enqueued via the task_struct's rcu_node_entry list_head onto one of the rcu_node's blocked_tasks[] lists. These tasks need to be moved somewhere else so that they will prevent the current grace period from ending. That somewhere is the root rcu_node. Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <20090827215816.GA30472@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar --- include/linux/init_task.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 79d4baee31b6..9e7f2e8fc66e 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -98,7 +98,7 @@ extern struct group_info init_groups; #define INIT_TASK_RCU_PREEMPT(tsk) \ .rcu_read_lock_nesting = 0, \ .rcu_read_unlock_special = 0, \ - .rcu_blocked_cpu = -1, \ + .rcu_blocked_node = NULL, \ .rcu_node_entry = LIST_HEAD_INIT(tsk.rcu_node_entry), #else #define INIT_TASK_RCU_PREEMPT(tsk) -- cgit v1.2.3 From cdd6c482c9ff9c55475ee7392ec8f672eddb7be6 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 21 Sep 2009 12:02:48 +0200 Subject: perf: Do the big rename: Performance Counters -> Performance Events Bye-bye Performance Counters, welcome Performance Events! In the past few months the perfcounters subsystem has grown out its initial role of counting hardware events, and has become (and is becoming) a much broader generic event enumeration, reporting, logging, monitoring, analysis facility. Naming its core object 'perf_counter' and naming the subsystem 'perfcounters' has become more and more of a misnomer. With pending code like hw-breakpoints support the 'counter' name is less and less appropriate. All in one, we've decided to rename the subsystem to 'performance events' and to propagate this rename through all fields, variables and API names. (in an ABI compatible fashion) The word 'event' is also a bit shorter than 'counter' - which makes it slightly more convenient to write/handle as well. Thanks goes to Stephane Eranian who first observed this misnomer and suggested a rename. User-space tooling and ABI compatibility is not affected - this patch should be function-invariant. (Also, defconfigs were not touched to keep the size down.) This patch has been generated via the following script: FILES=$(find * -type f | grep -vE 'oprofile|[^K]config') sed -i \ -e 's/PERF_EVENT_/PERF_RECORD_/g' \ -e 's/PERF_COUNTER/PERF_EVENT/g' \ -e 's/perf_counter/perf_event/g' \ -e 's/nb_counters/nb_events/g' \ -e 's/swcounter/swevent/g' \ -e 's/tpcounter_event/tp_event/g' \ $FILES for N in $(find . -name perf_counter.[ch]); do M=$(echo $N | sed 's/perf_counter/perf_event/g') mv $N $M done FILES=$(find . -name perf_event.*) sed -i \ -e 's/COUNTER_MASK/REG_MASK/g' \ -e 's/COUNTER/EVENT/g' \ -e 's/\/event_id/g' \ -e 's/counter/event/g' \ -e 's/Counter/Event/g' \ $FILES ... to keep it as correct as possible. This script can also be used by anyone who has pending perfcounters patches - it converts a Linux kernel tree over to the new naming. We tried to time this change to the point in time where the amount of pending patches is the smallest: the end of the merge window. Namespace clashes were fixed up in a preparatory patch - and some stylistic fallout will be fixed up in a subsequent patch. ( NOTE: 'counters' are still the proper terminology when we deal with hardware registers - and these sed scripts are a bit over-eager in renaming them. I've undone some of that, but in case there's something left where 'counter' would be better than 'event' we can undo that on an individual basis instead of touching an otherwise nicely automated patch. ) Suggested-by: Stephane Eranian Acked-by: Peter Zijlstra Acked-by: Paul Mackerras Reviewed-by: Arjan van de Ven Cc: Mike Galbraith Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: Steven Rostedt Cc: Benjamin Herrenschmidt Cc: David Howells Cc: Kyle McMartin Cc: Martin Schwidefsky Cc: "David S. Miller" Cc: Thomas Gleixner Cc: "H. Peter Anvin" Cc: LKML-Reference: Signed-off-by: Ingo Molnar --- include/linux/init_task.h | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 9e7f2e8fc66e..21a6f5d9af22 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -106,13 +106,13 @@ extern struct group_info init_groups; extern struct cred init_cred; -#ifdef CONFIG_PERF_COUNTERS -# define INIT_PERF_COUNTERS(tsk) \ - .perf_counter_mutex = \ - __MUTEX_INITIALIZER(tsk.perf_counter_mutex), \ - .perf_counter_list = LIST_HEAD_INIT(tsk.perf_counter_list), +#ifdef CONFIG_PERF_EVENTS +# define INIT_PERF_EVENTS(tsk) \ + .perf_event_mutex = \ + __MUTEX_INITIALIZER(tsk.perf_event_mutex), \ + .perf_event_list = LIST_HEAD_INIT(tsk.perf_event_list), #else -# define INIT_PERF_COUNTERS(tsk) +# define INIT_PERF_EVENTS(tsk) #endif /* @@ -178,7 +178,7 @@ extern struct cred init_cred; }, \ .dirties = INIT_PROP_LOCAL_SINGLE(dirties), \ INIT_IDS \ - INIT_PERF_COUNTERS(tsk) \ + INIT_PERF_EVENTS(tsk) \ INIT_TRACE_IRQFLAGS \ INIT_LOCKDEP \ INIT_FTRACE_GRAPH \ -- cgit v1.2.3 From b3a222e52e4d4be77cc4520a57af1a4a0d8222d1 Mon Sep 17 00:00:00 2001 From: "Serge E. Hallyn" Date: Mon, 23 Nov 2009 16:21:30 -0600 Subject: remove CONFIG_SECURITY_FILE_CAPABILITIES compile option As far as I know, all distros currently ship kernels with default CONFIG_SECURITY_FILE_CAPABILITIES=y. Since having the option on leaves a 'no_file_caps' option to boot without file capabilities, the main reason to keep the option is that turning it off saves you (on my s390x partition) 5k. In particular, vmlinux sizes came to: without patch fscaps=n: 53598392 without patch fscaps=y: 53603406 with this patch applied: 53603342 with the security-next tree. Against this we must weigh the fact that there is no simple way for userspace to figure out whether file capabilities are supported, while things like per-process securebits, capability bounding sets, and adding bits to pI if CAP_SETPCAP is in pE are not supported with SECURITY_FILE_CAPABILITIES=n, leaving a bit of a problem for applications wanting to know whether they can use them and/or why something failed. It also adds another subtly different set of semantics which we must maintain at the risk of severe security regressions. So this patch removes the SECURITY_FILE_CAPABILITIES compile option. It drops the kernel size by about 50k over the stock SECURITY_FILE_CAPABILITIES=y kernel, by removing the cap_limit_ptraced_target() function. Changelog: Nov 20: remove cap_limit_ptraced_target() as it's logic was ifndef'ed. Signed-off-by: Serge E. Hallyn Acked-by: Andrew G. Morgan" Signed-off-by: James Morris --- include/linux/init_task.h | 4 ---- 1 file changed, 4 deletions(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 21a6f5d9af22..8d10aa7fd4c9 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -83,16 +83,12 @@ extern struct group_info init_groups; #define INIT_IDS #endif -#ifdef CONFIG_SECURITY_FILE_CAPABILITIES /* * Because of the reduced scope of CAP_SETPCAP when filesystem * capabilities are in effect, it is safe to allow CAP_SETPCAP to * be available in the default configuration. */ # define CAP_INIT_BSET CAP_FULL_SET -#else -# define CAP_INIT_BSET CAP_INIT_EFF_SET -#endif #ifdef CONFIG_TREE_PREEMPT_RCU #define INIT_TASK_RCU_PREEMPT(tsk) \ -- cgit v1.2.3 From 1d615482547584b9a8bb6316a58fed6ce90dd9ff Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 17 Nov 2009 14:54:03 +0100 Subject: sched: Convert pi_lock to raw_spinlock Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Acked-by: Ingo Molnar --- include/linux/init_task.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 8d10aa7fd4c9..abec69b63d7e 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -165,7 +165,7 @@ extern struct cred init_cred; .journal_info = NULL, \ .cpu_timers = INIT_CPU_TIMERS(tsk.cpu_timers), \ .fs_excl = ATOMIC_INIT(0), \ - .pi_lock = __SPIN_LOCK_UNLOCKED(tsk.pi_lock), \ + .pi_lock = __RAW_SPIN_LOCK_UNLOCKED(tsk.pi_lock), \ .timer_slack_ns = 50000, /* 50 usec default slack */ \ .pids = { \ [PIDTYPE_PID] = INIT_PID_LINK(PIDTYPE_PID), \ -- cgit v1.2.3 From e4c570c4cb7a95dbfafa3d016d2739bf3fdfe319 Mon Sep 17 00:00:00 2001 From: Hiroshi Shimamoto Date: Mon, 14 Dec 2009 18:00:26 -0800 Subject: task_struct: make journal_info conditional journal_info in task_struct is used in journaling file system only. So introduce CONFIG_FS_JOURNAL_INFO and make it conditional. Signed-off-by: Hiroshi Shimamoto Cc: Chris Mason Cc: "Theodore Ts'o" Cc: Steven Whitehouse Cc: KONISHI Ryusuke Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/init_task.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 8d10aa7fd4c9..8ed0abf06f89 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -111,6 +111,12 @@ extern struct cred init_cred; # define INIT_PERF_EVENTS(tsk) #endif +#ifdef CONFIG_FS_JOURNAL_INFO +#define INIT_JOURNAL_INFO .journal_info = NULL, +#else +#define INIT_JOURNAL_INFO +#endif + /* * INIT_TASK is used to set up the first task table, touch at * your own risk!. Base=0, limit=0x1fffff (=2MB) @@ -162,7 +168,6 @@ extern struct cred init_cred; .signal = {{0}}}, \ .blocked = {{0}}, \ .alloc_lock = __SPIN_LOCK_UNLOCKED(tsk.alloc_lock), \ - .journal_info = NULL, \ .cpu_timers = INIT_CPU_TIMERS(tsk.cpu_timers), \ .fs_excl = ATOMIC_INIT(0), \ .pi_lock = __SPIN_LOCK_UNLOCKED(tsk.pi_lock), \ @@ -173,6 +178,7 @@ extern struct cred init_cred; [PIDTYPE_SID] = INIT_PID_LINK(PIDTYPE_SID), \ }, \ .dirties = INIT_PROP_LOCAL_SINGLE(dirties), \ + INIT_JOURNAL_INFO \ INIT_IDS \ INIT_PERF_EVENTS(tsk) \ INIT_TRACE_IRQFLAGS \ -- cgit v1.2.3 From b6e3224fb20954f155e41ec5709b2ab70b50ae2d Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Thu, 17 Dec 2009 13:23:24 -0800 Subject: Revert "task_struct: make journal_info conditional" This reverts commit e4c570c4cb7a95dbfafa3d016d2739bf3fdfe319, as requested by Alexey: "I think I gave a good enough arguments to not merge it. To iterate: * patch makes impossible to start using ext3 on EXT3_FS=n kernels without reboot. * this is done only for one pointer on task_struct" None of config options which define task_struct are tristate directly or effectively." Requested-by: Alexey Dobriyan Acked-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/init_task.h | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 5ed8b9c50355..abec69b63d7e 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -111,12 +111,6 @@ extern struct cred init_cred; # define INIT_PERF_EVENTS(tsk) #endif -#ifdef CONFIG_FS_JOURNAL_INFO -#define INIT_JOURNAL_INFO .journal_info = NULL, -#else -#define INIT_JOURNAL_INFO -#endif - /* * INIT_TASK is used to set up the first task table, touch at * your own risk!. Base=0, limit=0x1fffff (=2MB) @@ -168,6 +162,7 @@ extern struct cred init_cred; .signal = {{0}}}, \ .blocked = {{0}}, \ .alloc_lock = __SPIN_LOCK_UNLOCKED(tsk.alloc_lock), \ + .journal_info = NULL, \ .cpu_timers = INIT_CPU_TIMERS(tsk.cpu_timers), \ .fs_excl = ATOMIC_INIT(0), \ .pi_lock = __RAW_SPIN_LOCK_UNLOCKED(tsk.pi_lock), \ @@ -178,7 +173,6 @@ extern struct cred init_cred; [PIDTYPE_SID] = INIT_PID_LINK(PIDTYPE_SID), \ }, \ .dirties = INIT_PROP_LOCAL_SINGLE(dirties), \ - INIT_JOURNAL_INFO \ INIT_IDS \ INIT_PERF_EVENTS(tsk) \ INIT_TRACE_IRQFLAGS \ -- cgit v1.2.3 From 2af7687f1ad2c4571b9835f9bb2e3db9a738d258 Mon Sep 17 00:00:00 2001 From: Tim Abbott Date: Sat, 20 Feb 2010 01:03:35 +0100 Subject: Rename .data.init_task to .data..init_task. Signed-off-by: Tim Abbott Cc: Sam Ravnborg Signed-off-by: Denys Vlasenko Signed-off-by: Michal Marek --- include/linux/init_task.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index abec69b63d7e..f00253b3fc47 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -191,7 +191,7 @@ extern struct cred init_cred; } /* Attach to the init_task data structure for proper alignment */ -#define __init_task_data __attribute__((__section__(".data.init_task"))) +#define __init_task_data __attribute__((__section__(".data..init_task"))) #endif -- cgit v1.2.3 From 8467005da3ef6104b89a4cc5e9c9d9445b75565f Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Wed, 10 Mar 2010 15:23:10 -0800 Subject: nsproxy: remove INIT_NSPROXY() Remove INIT_NSPROXY(), use C99 initializer. Remove INIT_IPC_NS(), INIT_NET_NS() while I'm at it. Note: headers trim will be done later, now it's quite pointless because results will be invalidated by merge window. Signed-off-by: Alexey Dobriyan Acked-by: Serge Hallyn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/init_task.h | 8 -------- 1 file changed, 8 deletions(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index abec69b63d7e..b1ed1cd8e2a8 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -32,14 +32,6 @@ extern struct fs_struct init_fs; } extern struct nsproxy init_nsproxy; -#define INIT_NSPROXY(nsproxy) { \ - .pid_ns = &init_pid_ns, \ - .count = ATOMIC_INIT(1), \ - .uts_ns = &init_uts_ns, \ - .mnt_ns = NULL, \ - INIT_NET_NS(net_ns) \ - INIT_IPC_NS(ipc_ns) \ -} #define INIT_SIGHAND(sighand) { \ .count = ATOMIC_INIT(1), \ -- cgit v1.2.3 From 72d5a9f7a9542f88397558c65bcfc3b115a65e34 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 10 May 2010 17:12:17 -0700 Subject: rcu: remove all rcu head initializations, except on_stack initializations Remove all rcu head inits. We don't care about the RCU head state before passing it to call_rcu() anyway. Only leave the "on_stack" variants so debugobjects can keep track of objects on stack. Signed-off-by: Mathieu Desnoyers Signed-off-by: Paul E. McKenney --- include/linux/init_task.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index b1ed1cd8e2a8..7996fc2c9ba9 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -49,7 +49,6 @@ extern struct group_info init_groups; { .first = &init_task.pids[PIDTYPE_PGID].node }, \ { .first = &init_task.pids[PIDTYPE_SID].node }, \ }, \ - .rcu = RCU_HEAD_INIT, \ .level = 0, \ .numbers = { { \ .nr = 0, \ -- cgit v1.2.3 From b3ac022cb9dc5883505a88b159d1b240ad1ef405 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 26 May 2010 14:43:24 -0700 Subject: proc: turn signal_struct->count into "int nr_threads" No functional changes, just s/atomic_t count/int nr_threads/. With the recent changes this counter has a single user, get_nr_threads() And, none of its callers need the really accurate number of threads, not to mention each caller obviously races with fork/exit. It is only used to report this value to the user-space, except first_tid() uses it to avoid the unnecessary while_each_thread() loop in the unlikely case. It is a bit sad we need a word in struct signal_struct for this, perhaps we can change get_nr_threads() to approximate the number of threads using signal->live and kill ->nr_threads later. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Oleg Nesterov Cc: Alexey Dobriyan Cc: "Eric W. Biederman" Acked-by: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/init_task.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 7996fc2c9ba9..0551e0dcb71b 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -16,7 +16,7 @@ extern struct files_struct init_files; extern struct fs_struct init_fs; #define INIT_SIGNALS(sig) { \ - .count = ATOMIC_INIT(1), \ + .nr_threads = 1, \ .wait_chldexit = __WAIT_QUEUE_HEAD_INITIALIZER(sig.wait_chldexit),\ .shared_pending = { \ .list = LIST_HEAD_INIT(sig.shared_pending.list), \ -- cgit v1.2.3 From fa2755e20ab0c7215d99c2dc7c262e98a09b01df Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 26 May 2010 14:44:08 -0700 Subject: INIT_TASK() should initialize ->thread_group list The trivial /sbin/init doing int main(void) { kill(0, SIGKILL) } crashes the kernel. This happens because __kill_pgrp_info(init_struct_pid) also sends SIGKILL to the swapper process which runs with the uninitialized ->thread_group. Change INIT_TASK() to initialize ->thread_group properly. Note: the real problem is that the swapper process must not be visible to signals, see the next patch. But this change is right anyway and fixes the crash. Reported-and-tested-by: Mathias Krause Signed-off-by: Oleg Nesterov Cc: Cedric Le Goater Cc: Dave Hansen Cc: Eric Biederman Cc: Herbert Poetzl Cc: Mathias Krause Acked-by: Roland McGrath Acked-by: Serge Hallyn Acked-by: Sukadev Bhattiprolu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/init_task.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 0551e0dcb71b..6deb1ba52fdb 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -163,6 +163,7 @@ extern struct cred init_cred; [PIDTYPE_PGID] = INIT_PID_LINK(PIDTYPE_PGID), \ [PIDTYPE_SID] = INIT_PID_LINK(PIDTYPE_SID), \ }, \ + .thread_group = LIST_HEAD_INIT(tsk.thread_group), \ .dirties = INIT_PROP_LOCAL_SINGLE(dirties), \ INIT_IDS \ INIT_PERF_EVENTS(tsk) \ -- cgit v1.2.3 From f20011457f41c11edb5ea5038ad0c8ea9f392023 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 26 May 2010 14:44:10 -0700 Subject: pids: init_struct_pid.tasks should never see the swapper process "statically initialize struct pid for swapper" commit 820e45db says: Statically initialize a struct pid for the swapper process (pid_t == 0) and attach it to init_task. This is needed so task_pid(), task_pgrp() and task_session() interfaces work on the swapper process also. OK, but: - it doesn't make sense to add init_task.pids[].node into init_struct_pid.tasks[], and in fact this just wrong. idle threads are special, they shouldn't be visible on any global list. In particular do_each_pid_task(init_struct_pid) shouldn't see swapper. This is the actual reason why kill(0, SIGKILL) from /sbin/init (which starts with 0,0 special pids) crashes the kernel. The signal sent to pgid/sid == 0 must never see idle threads, even if the previous patch fixed the crash itself. - we have other idle threads running on the non-boot CPUs, see the next patch. Change INIT_STRUCT_PID/INIT_PID_LINK to create the empty/unhashed hlist_head/hlist_node. Like any other idle thread swapper can never exit, so detach_pid()->__hlist_del() is not possible, but we could change INIT_PID_LINK() to set pprev = &next if needed. All we need is the valid swapper->pids[].pid == &init_struct_pid. Reported-by: Mathias Krause Signed-off-by: Oleg Nesterov Cc: Cedric Le Goater Cc: Dave Hansen Cc: Eric Biederman Cc: Herbert Poetzl Cc: Mathias Krause Acked-by: Roland McGrath Acked-by: Serge Hallyn Cc: Sukadev Bhattiprolu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/init_task.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 6deb1ba52fdb..94fecb748a28 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -45,9 +45,9 @@ extern struct group_info init_groups; #define INIT_STRUCT_PID { \ .count = ATOMIC_INIT(1), \ .tasks = { \ - { .first = &init_task.pids[PIDTYPE_PID].node }, \ - { .first = &init_task.pids[PIDTYPE_PGID].node }, \ - { .first = &init_task.pids[PIDTYPE_SID].node }, \ + { .first = NULL }, \ + { .first = NULL }, \ + { .first = NULL }, \ }, \ .level = 0, \ .numbers = { { \ @@ -61,7 +61,7 @@ extern struct group_info init_groups; { \ .node = { \ .next = NULL, \ - .pprev = &init_struct_pid.tasks[type].first, \ + .pprev = NULL, \ }, \ .pid = &init_struct_pid, \ } -- cgit v1.2.3 From 0a14a130cac9c6826bc81a089b12ab5cbb2b97fc Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 26 May 2010 14:44:12 -0700 Subject: INIT_SIGHAND: use SIG_DFL instead of NULL Cosmetic, no changes in the compiled code. Just s/NULL/SIG_DFL/ to make it more readable and grep-friendly. Note: probably SIG_IGN makes more sense, we could kill ignore_signals(). But then kernel_init() should do flush_signal_handlers() before exec(). Signed-off-by: Oleg Nesterov Cc: Cedric Le Goater Cc: Dave Hansen Cc: Eric Biederman Cc: Herbert Poetzl Cc: Mathias Krause Acked-by: Roland McGrath Acked-by: Serge Hallyn Cc: Sukadev Bhattiprolu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/init_task.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 94fecb748a28..2beaa13492be 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -35,7 +35,7 @@ extern struct nsproxy init_nsproxy; #define INIT_SIGHAND(sighand) { \ .count = ATOMIC_INIT(1), \ - .action = { { { .sa_handler = NULL, } }, }, \ + .action = { { { .sa_handler = SIG_DFL, } }, }, \ .siglock = __SPIN_LOCK_UNLOCKED(sighand.siglock), \ .signalfd_wqh = __WAIT_QUEUE_HEAD_INITIALIZER(sighand.signalfd_wqh), \ } -- cgit v1.2.3 From 4d2deb40b20c2608486598364e63e37b09a9ac2f Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 24 Feb 2010 20:01:56 +0100 Subject: kernel: __rcu annotations This adds annotations for RCU operations in core kernel components Signed-off-by: Arnd Bergmann Signed-off-by: Paul E. McKenney Cc: Al Viro Cc: Jens Axboe Cc: Andrew Morton Reviewed-by: Josh Triplett --- include/linux/init_task.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 1f43fa56f600..6460fc65ed6b 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -137,8 +137,8 @@ extern struct cred init_cred; .children = LIST_HEAD_INIT(tsk.children), \ .sibling = LIST_HEAD_INIT(tsk.sibling), \ .group_leader = &tsk, \ - .real_cred = &init_cred, \ - .cred = &init_cred, \ + RCU_INIT_POINTER(.real_cred, &init_cred), \ + RCU_INIT_POINTER(.cred, &init_cred), \ .cred_guard_mutex = \ __MUTEX_INITIALIZER(tsk.cred_guard_mutex), \ .comm = "swapper", \ -- cgit v1.2.3 From a57eb940d130477a799dfb24a570ee04979c0f7f Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 29 Jun 2010 16:49:16 -0700 Subject: rcu: Add a TINY_PREEMPT_RCU MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Implement a small-memory-footprint uniprocessor-only implementation of preemptible RCU. This implementation uses but a single blocked-tasks list rather than the combinatorial number used per leaf rcu_node by TREE_PREEMPT_RCU, which reduces memory consumption and greatly simplifies processing. This version also takes advantage of uniprocessor execution to accelerate grace periods in the case where there are no readers. The general design is otherwise broadly similar to that of TREE_PREEMPT_RCU. This implementation is a step towards having RCU implementation driven off of the SMP and PREEMPT kernel configuration variables, which can happen once this implementation has accumulated sufficient experience. Removed ACCESS_ONCE() from __rcu_read_unlock() and added barrier() as suggested by Steve Rostedt in order to avoid the compiler-reordering issue noted by Mathieu Desnoyers (http://lkml.org/lkml/2010/8/16/183). As can be seen below, CONFIG_TINY_PREEMPT_RCU represents almost 5Kbyte savings compared to CONFIG_TREE_PREEMPT_RCU. Of course, for non-real-time workloads, CONFIG_TINY_RCU is even better. CONFIG_TREE_PREEMPT_RCU text data bss dec filename 13 0 0 13 kernel/rcupdate.o 6170 825 28 7023 kernel/rcutree.o ---- 7026 Total CONFIG_TINY_PREEMPT_RCU text data bss dec filename 13 0 0 13 kernel/rcupdate.o 2081 81 8 2170 kernel/rcutiny.o ---- 2183 Total CONFIG_TINY_RCU (non-preemptible) text data bss dec filename 13 0 0 13 kernel/rcupdate.o 719 25 0 744 kernel/rcutiny.o --- 757 Total Requested-by: Loïc Minier Signed-off-by: Paul E. McKenney --- include/linux/init_task.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 6460fc65ed6b..2fea6c8ef6ba 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -82,11 +82,17 @@ extern struct group_info init_groups; # define CAP_INIT_BSET CAP_FULL_SET #ifdef CONFIG_TREE_PREEMPT_RCU +#define INIT_TASK_RCU_TREE_PREEMPT() \ + .rcu_blocked_node = NULL, +#else +#define INIT_TASK_RCU_TREE_PREEMPT(tsk) +#endif +#ifdef CONFIG_PREEMPT_RCU #define INIT_TASK_RCU_PREEMPT(tsk) \ .rcu_read_lock_nesting = 0, \ .rcu_read_unlock_special = 0, \ - .rcu_blocked_node = NULL, \ - .rcu_node_entry = LIST_HEAD_INIT(tsk.rcu_node_entry), + .rcu_node_entry = LIST_HEAD_INIT(tsk.rcu_node_entry), \ + INIT_TASK_RCU_TREE_PREEMPT() #else #define INIT_TASK_RCU_PREEMPT(tsk) #endif -- cgit v1.2.3 From 9b1bf12d5d51bca178dea21b04a0805e29d60cf1 Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Wed, 27 Oct 2010 15:34:08 -0700 Subject: signals: move cred_guard_mutex from task_struct to signal_struct Oleg Nesterov pointed out we have to prevent multiple-threads-inside-exec itself and we can reuse ->cred_guard_mutex for it. Yes, concurrent execve() has no worth. Let's move ->cred_guard_mutex from task_struct to signal_struct. It naturally prevent multiple-threads-inside-exec. Signed-off-by: KOSAKI Motohiro Reviewed-by: Oleg Nesterov Acked-by: Roland McGrath Acked-by: David Howells Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/init_task.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 2fea6c8ef6ba..1f8c06ce0fa6 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -29,6 +29,8 @@ extern struct fs_struct init_fs; .running = 0, \ .lock = __SPIN_LOCK_UNLOCKED(sig.cputimer.lock), \ }, \ + .cred_guard_mutex = \ + __MUTEX_INITIALIZER(sig.cred_guard_mutex), \ } extern struct nsproxy init_nsproxy; @@ -145,8 +147,6 @@ extern struct cred init_cred; .group_leader = &tsk, \ RCU_INIT_POINTER(.real_cred, &init_cred), \ RCU_INIT_POINTER(.cred, &init_cred), \ - .cred_guard_mutex = \ - __MUTEX_INITIALIZER(tsk.cred_guard_mutex), \ .comm = "swapper", \ .thread = INIT_THREAD, \ .fs = &init_fs, \ -- cgit v1.2.3 From 24278d148316d2180be6df40e06db013d8b232b8 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 27 Sep 2010 17:25:23 -0700 Subject: rcu: priority boosting for TINY_PREEMPT_RCU Add priority boosting, but only for TINY_PREEMPT_RCU. This is enabled by the default-off RCU_BOOST kernel parameter. The priority to which to boost preempted RCU readers is controlled by the RCU_BOOST_PRIO kernel parameter (defaulting to real-time priority 1) and the time to wait before boosting the readers blocking a given grace period is controlled by the RCU_BOOST_DELAY kernel parameter (defaulting to 500 milliseconds). Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney --- include/linux/init_task.h | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 2fea6c8ef6ba..69f91aacdeee 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -81,6 +81,12 @@ extern struct group_info init_groups; */ # define CAP_INIT_BSET CAP_FULL_SET +#ifdef CONFIG_RCU_BOOST +#define INIT_TASK_RCU_BOOST() \ + .rcu_boost_mutex = NULL, +#else +#define INIT_TASK_RCU_BOOST() +#endif #ifdef CONFIG_TREE_PREEMPT_RCU #define INIT_TASK_RCU_TREE_PREEMPT() \ .rcu_blocked_node = NULL, @@ -92,7 +98,8 @@ extern struct group_info init_groups; .rcu_read_lock_nesting = 0, \ .rcu_read_unlock_special = 0, \ .rcu_node_entry = LIST_HEAD_INIT(tsk.rcu_node_entry), \ - INIT_TASK_RCU_TREE_PREEMPT() + INIT_TASK_RCU_TREE_PREEMPT() \ + INIT_TASK_RCU_BOOST() #else #define INIT_TASK_RCU_PREEMPT(tsk) #endif -- cgit v1.2.3 From 806c09a7db457be3758e14b1f152761135d89af5 Mon Sep 17 00:00:00 2001 From: Dario Faggioli Date: Tue, 30 Nov 2010 19:51:33 +0100 Subject: sched: Make pushable_tasks CONFIG_SMP dependant As noted by Peter Zijlstra at https://lkml.org/lkml/2010/11/10/391 (while reviewing other stuff, though), tracking pushable tasks only makes sense on SMP systems. Signed-off-by: Dario Faggioli Acked-by: Steven Rostedt Acked-by: Gregory Haskins Signed-off-by: Peter Zijlstra LKML-Reference: <1291143093.2697.298.camel@Palantir> Signed-off-by: Ingo Molnar --- include/linux/init_task.h | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 1f8c06ce0fa6..6ed8812bfe2d 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -12,6 +12,13 @@ #include #include +#ifdef CONFIG_SMP +# define INIT_PUSHABLE_TASKS(tsk) \ + .pushable_tasks = PLIST_NODE_INIT(tsk.pushable_tasks, MAX_PRIO), +#else +# define INIT_PUSHABLE_TASKS(tsk) +#endif + extern struct files_struct init_files; extern struct fs_struct init_fs; @@ -137,7 +144,7 @@ extern struct cred init_cred; .nr_cpus_allowed = NR_CPUS, \ }, \ .tasks = LIST_HEAD_INIT(tsk.tasks), \ - .pushable_tasks = PLIST_NODE_INIT(tsk.pushable_tasks, MAX_PRIO), \ + INIT_PUSHABLE_TASKS(tsk) \ .ptraced = LIST_HEAD_INIT(tsk.ptraced), \ .ptrace_entry = LIST_HEAD_INIT(tsk.ptrace_entry), \ .real_parent = &tsk, \ -- cgit v1.2.3