--- /dev/null
+From 1306d603fcf1f6682f8575d1ff23631a24184b21 Mon Sep 17 00:00:00 2001
+From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
+Date: Fri, 8 Jan 2010 14:42:56 -0800
+Subject: proc: partially revert "procfs: provide stack information for threads"
+
+From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
+
+commit 1306d603fcf1f6682f8575d1ff23631a24184b21 upstream.
+
+Commit d899bf7b (procfs: provide stack information for threads) introduced
+to show stack information in /proc/{pid}/status. But it cause large
+performance regression. Unfortunately /proc/{pid}/status is used ps
+command too and ps is one of most important component. Because both to
+take mmap_sem and page table walk are heavily operation.
+
+If many process run, the ps performance is,
+
+[before d899bf7b]
+
+% perf stat ps >/dev/null
+
+ Performance counter stats for 'ps':
+
+ 4090.435806 task-clock-msecs # 0.032 CPUs
+ 229 context-switches # 0.000 M/sec
+ 0 CPU-migrations # 0.000 M/sec
+ 234 page-faults # 0.000 M/sec
+ 8587565207 cycles # 2099.425 M/sec
+ 9866662403 instructions # 1.149 IPC
+ 3789415411 cache-references # 926.409 M/sec
+ 30419509 cache-misses # 7.437 M/sec
+
+ 128.859521955 seconds time elapsed
+
+[after d899bf7b]
+
+% perf stat ps > /dev/null
+
+ Performance counter stats for 'ps':
+
+ 4305.081146 task-clock-msecs # 0.028 CPUs
+ 480 context-switches # 0.000 M/sec
+ 2 CPU-migrations # 0.000 M/sec
+ 237 page-faults # 0.000 M/sec
+ 9021211334 cycles # 2095.480 M/sec
+ 10605887536 instructions # 1.176 IPC
+ 3612650999 cache-references # 839.160 M/sec
+ 23917502 cache-misses # 5.556 M/sec
+
+ 152.277819582 seconds time elapsed
+
+Thus, this patch revert it. Fortunately /proc/{pid}/task/{tid}/smaps
+provide almost same information. we can use it.
+
+Commit d899bf7b introduced two features:
+
+ 1) Add the annotattion of [thread stack: xxxx] mark to
+ /proc/{pid}/task/{tid}/maps.
+ 2) Add StackUsage field to /proc/{pid}/status.
+
+I only revert (2), because I haven't seen (1) cause regression.
+
+Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
+Cc: Stefani Seibold <stefani@seibold.net>
+Cc: Ingo Molnar <mingo@elte.hu>
+Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
+Cc: Alexey Dobriyan <adobriyan@gmail.com>
+Cc: "Eric W. Biederman" <ebiederm@xmission.com>
+Cc: Randy Dunlap <randy.dunlap@oracle.com>
+Cc: Andrew Morton <akpm@linux-foundation.org>
+Cc: Andi Kleen <andi@firstfloor.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@suse.de>
+
+---
+ Documentation/filesystems/proc.txt | 2
+ fs/proc/array.c | 89 -------------------------------------
+ 2 files changed, 91 deletions(-)
+
+--- a/Documentation/filesystems/proc.txt
++++ b/Documentation/filesystems/proc.txt
+@@ -176,7 +176,6 @@ read the file /proc/PID/status:
+ CapBnd: ffffffffffffffff
+ voluntary_ctxt_switches: 0
+ nonvoluntary_ctxt_switches: 1
+- Stack usage: 12 kB
+
+ This shows you nearly the same information you would get if you viewed it with
+ the ps command. In fact, ps uses the proc file system to obtain its
+@@ -230,7 +229,6 @@ Table 1-2: Contents of the statm files (
+ Mems_allowed_list Same as previous, but in "list format"
+ voluntary_ctxt_switches number of voluntary context switches
+ nonvoluntary_ctxt_switches number of non voluntary context switches
+- Stack usage: stack usage high water mark (round up to page size)
+ ..............................................................................
+
+ Table 1-3: Contents of the statm files (as of 2.6.8-rc3)
+--- a/fs/proc/array.c
++++ b/fs/proc/array.c
+@@ -322,94 +322,6 @@ static inline void task_context_switch_c
+ p->nivcsw);
+ }
+
+-#ifdef CONFIG_MMU
+-
+-struct stack_stats {
+- struct vm_area_struct *vma;
+- unsigned long startpage;
+- unsigned long usage;
+-};
+-
+-static int stack_usage_pte_range(pmd_t *pmd, unsigned long addr,
+- unsigned long end, struct mm_walk *walk)
+-{
+- struct stack_stats *ss = walk->private;
+- struct vm_area_struct *vma = ss->vma;
+- pte_t *pte, ptent;
+- spinlock_t *ptl;
+- int ret = 0;
+-
+- pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+- for (; addr != end; pte++, addr += PAGE_SIZE) {
+- ptent = *pte;
+-
+-#ifdef CONFIG_STACK_GROWSUP
+- if (pte_present(ptent) || is_swap_pte(ptent))
+- ss->usage = addr - ss->startpage + PAGE_SIZE;
+-#else
+- if (pte_present(ptent) || is_swap_pte(ptent)) {
+- ss->usage = ss->startpage - addr + PAGE_SIZE;
+- pte++;
+- ret = 1;
+- break;
+- }
+-#endif
+- }
+- pte_unmap_unlock(pte - 1, ptl);
+- cond_resched();
+- return ret;
+-}
+-
+-static inline unsigned long get_stack_usage_in_bytes(struct vm_area_struct *vma,
+- struct task_struct *task)
+-{
+- struct stack_stats ss;
+- struct mm_walk stack_walk = {
+- .pmd_entry = stack_usage_pte_range,
+- .mm = vma->vm_mm,
+- .private = &ss,
+- };
+-
+- if (!vma->vm_mm || is_vm_hugetlb_page(vma))
+- return 0;
+-
+- ss.vma = vma;
+- ss.startpage = task->stack_start & PAGE_MASK;
+- ss.usage = 0;
+-
+-#ifdef CONFIG_STACK_GROWSUP
+- walk_page_range(KSTK_ESP(task) & PAGE_MASK, vma->vm_end,
+- &stack_walk);
+-#else
+- walk_page_range(vma->vm_start, (KSTK_ESP(task) & PAGE_MASK) + PAGE_SIZE,
+- &stack_walk);
+-#endif
+- return ss.usage;
+-}
+-
+-static inline void task_show_stack_usage(struct seq_file *m,
+- struct task_struct *task)
+-{
+- struct vm_area_struct *vma;
+- struct mm_struct *mm = get_task_mm(task);
+-
+- if (mm) {
+- down_read(&mm->mmap_sem);
+- vma = find_vma(mm, task->stack_start);
+- if (vma)
+- seq_printf(m, "Stack usage:\t%lu kB\n",
+- get_stack_usage_in_bytes(vma, task) >> 10);
+-
+- up_read(&mm->mmap_sem);
+- mmput(mm);
+- }
+-}
+-#else
+-static void task_show_stack_usage(struct seq_file *m, struct task_struct *task)
+-{
+-}
+-#endif /* CONFIG_MMU */
+-
+ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *task)
+ {
+@@ -429,7 +341,6 @@ int proc_pid_status(struct seq_file *m,
+ task_show_regs(m, task);
+ #endif
+ task_context_switch_counts(m, task);
+- task_show_stack_usage(m, task);
+ return 0;
+ }
+
--- /dev/null
+From 34441427aab4bdb3069a4ffcda69a99357abcb2e Mon Sep 17 00:00:00 2001
+From: Robin Holt <holt@sgi.com>
+Date: Tue, 11 May 2010 14:06:46 -0700
+Subject: revert "procfs: provide stack information for threads" and its fixup commits
+
+From: Robin Holt <holt@sgi.com>
+
+commit 34441427aab4bdb3069a4ffcda69a99357abcb2e upstream.
+
+Originally, commit d899bf7b ("procfs: provide stack information for
+threads") attempted to introduce a new feature for showing where the
+threadstack was located and how many pages are being utilized by the
+stack.
+
+Commit c44972f1 ("procfs: disable per-task stack usage on NOMMU") was
+applied to fix the NO_MMU case.
+
+Commit 89240ba0 ("x86, fs: Fix x86 procfs stack information for threads on
+64-bit") was applied to fix a bug in ia32 executables being loaded.
+
+Commit 9ebd4eba7 ("procfs: fix /proc/<pid>/stat stack pointer for kernel
+threads") was applied to fix a bug which had kernel threads printing a
+userland stack address.
+
+Commit 1306d603f ('proc: partially revert "procfs: provide stack
+information for threads"') was then applied to revert the stack pages
+being used to solve a significant performance regression.
+
+This patch nearly undoes the effect of all these patches.
+
+The reason for reverting these is it provides an unusable value in
+field 28. For x86_64, a fork will result in the task->stack_start
+value being updated to the current user top of stack and not the stack
+start address. This unpredictability of the stack_start value makes
+it worthless. That includes the intended use of showing how much stack
+space a thread has.
+
+Other architectures will get different values. As an example, ia64
+gets 0. The do_fork() and copy_process() functions appear to treat the
+stack_start and stack_size parameters as architecture specific.
+
+I only partially reverted c44972f1 ("procfs: disable per-task stack usage
+on NOMMU") . If I had completely reverted it, I would have had to change
+mm/Makefile only build pagewalk.o when CONFIG_PROC_PAGE_MONITOR is
+configured. Since I could not test the builds without significant effort,
+I decided to not change mm/Makefile.
+
+I only partially reverted 89240ba0 ("x86, fs: Fix x86 procfs stack
+information for threads on 64-bit") . I left the KSTK_ESP() change in
+place as that seemed worthwhile.
+
+Signed-off-by: Robin Holt <holt@sgi.com>
+Cc: Stefani Seibold <stefani@seibold.net>
+Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
+Cc: Michal Simek <monstr@monstr.eu>
+Cc: Ingo Molnar <mingo@elte.hu>
+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@suse.de>
+
+---
+ Documentation/filesystems/proc.txt | 3 +--
+ fs/compat.c | 2 --
+ fs/exec.c | 2 --
+ fs/proc/array.c | 3 +--
+ fs/proc/task_mmu.c | 19 -------------------
+ include/linux/sched.h | 1 -
+ kernel/fork.c | 2 --
+ 7 files changed, 2 insertions(+), 30 deletions(-)
+
+--- a/Documentation/filesystems/proc.txt
++++ b/Documentation/filesystems/proc.txt
+@@ -307,7 +307,7 @@ address perms offset dev in
+ 08049000-0804a000 rw-p 00001000 03:00 8312 /opt/test
+ 0804a000-0806b000 rw-p 00000000 00:00 0 [heap]
+ a7cb1000-a7cb2000 ---p 00000000 00:00 0
+-a7cb2000-a7eb2000 rw-p 00000000 00:00 0 [threadstack:001ff4b4]
++a7cb2000-a7eb2000 rw-p 00000000 00:00 0
+ a7eb2000-a7eb3000 ---p 00000000 00:00 0
+ a7eb3000-a7ed5000 rw-p 00000000 00:00 0
+ a7ed5000-a8008000 r-xp 00000000 03:00 4222 /lib/libc.so.6
+@@ -343,7 +343,6 @@ is not associated with a file:
+ [stack] = the stack of the main process
+ [vdso] = the "virtual dynamic shared object",
+ the kernel system call handler
+- [threadstack:xxxxxxxx] = the stack of the thread, xxxxxxxx is the stack size
+
+ or if empty, the mapping is anonymous.
+
+--- a/fs/compat.c
++++ b/fs/compat.c
+@@ -1532,8 +1532,6 @@ int compat_do_execve(char * filename,
+ if (retval < 0)
+ goto out;
+
+- current->stack_start = current->mm->start_stack;
+-
+ /* execve succeeded */
+ current->fs->in_exec = 0;
+ current->in_execve = 0;
+--- a/fs/exec.c
++++ b/fs/exec.c
+@@ -1379,8 +1379,6 @@ int do_execve(char * filename,
+ if (retval < 0)
+ goto out;
+
+- current->stack_start = current->mm->start_stack;
+-
+ /* execve succeeded */
+ current->fs->in_exec = 0;
+ current->in_execve = 0;
+--- a/fs/proc/array.c
++++ b/fs/proc/array.c
+@@ -82,7 +82,6 @@
+ #include <linux/pid_namespace.h>
+ #include <linux/ptrace.h>
+ #include <linux/tracehook.h>
+-#include <linux/swapops.h>
+
+ #include <asm/pgtable.h>
+ #include <asm/processor.h>
+@@ -482,7 +481,7 @@ static int do_task_stat(struct seq_file
+ rsslim,
+ mm ? mm->start_code : 0,
+ mm ? mm->end_code : 0,
+- (permitted && mm) ? task->stack_start : 0,
++ (permitted && mm) ? mm->start_stack : 0,
+ esp,
+ eip,
+ /* The signal information here is obsolete.
+--- a/fs/proc/task_mmu.c
++++ b/fs/proc/task_mmu.c
+@@ -243,25 +243,6 @@ static void show_map_vma(struct seq_file
+ } else if (vma->vm_start <= mm->start_stack &&
+ vma->vm_end >= mm->start_stack) {
+ name = "[stack]";
+- } else {
+- unsigned long stack_start;
+- struct proc_maps_private *pmp;
+-
+- pmp = m->private;
+- stack_start = pmp->task->stack_start;
+-
+- if (vma->vm_start <= stack_start &&
+- vma->vm_end >= stack_start) {
+- pad_len_spaces(m, len);
+- seq_printf(m,
+- "[threadstack:%08lx]",
+-#ifdef CONFIG_STACK_GROWSUP
+- vma->vm_end - stack_start
+-#else
+- stack_start - vma->vm_start
+-#endif
+- );
+- }
+ }
+ } else {
+ name = "[vdso]";
+--- a/include/linux/sched.h
++++ b/include/linux/sched.h
+@@ -1541,7 +1541,6 @@ struct task_struct {
+ /* bitmask of trace recursion */
+ unsigned long trace_recursion;
+ #endif /* CONFIG_TRACING */
+- unsigned long stack_start;
+ };
+
+ /* Future-safe accessor for struct task_struct's cpus_allowed. */
+--- a/kernel/fork.c
++++ b/kernel/fork.c
+@@ -1123,8 +1123,6 @@ static struct task_struct *copy_process(
+
+ p->bts = NULL;
+
+- p->stack_start = stack_start;
+-
+ /* Perform scheduler related setup. Assign this task to a CPU. */
+ sched_fork(p, clone_flags);
+
x86-amd-check-x86_feature_osvw-bit-before-accessing-osvw-msrs.patch
btrfs-check-for-read-permission-on-src-file-in-the-clone-ioctl.patch
alsa-hda-new-intel-hda-controller.patch
+proc-partially-revert-procfs-provide-stack-information-for-threads.patch
+revert-procfs-provide-stack-information-for-threads-and-its-fixup-commits.patch
projects / thirdparty / kernel / stable-queue.git / commitdiff
