From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752442Ab2CAF0J (ORCPT ); Thu, 1 Mar 2012 00:26:09 -0500 Received: from mail-pw0-f46.google.com ([209.85.160.46]:56058 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751629Ab2CAF0F (ORCPT ); Thu, 1 Mar 2012 00:26:05 -0500 Authentication-Results: mr.google.com; spf=pass (google.com: domain of siddhesh.poyarekar@gmail.com designates 10.68.191.168 as permitted sender) smtp.mail=siddhesh.poyarekar@gmail.com; dkim=pass header.i=siddhesh.poyarekar@gmail.com From: Siddhesh Poyarekar To: Andrew Morton Cc: KOSAKI Motohiro , Alexander Viro , Jamie Lokier , Mike Frysinger , Alexey Dobriyan , Matt Mackall , linux-kernel@vger.kernel.org, Oleg Nesterov , Siddhesh Poyarekar Subject: [PATCH 2/2] procfs: Mark stack vma with pid of the owning task Date: Thu, 1 Mar 2012 10:50:59 +0530 Message-Id: <1330579259-3456-2-git-send-email-siddhesh.poyarekar@gmail.com> X-Mailer: git-send-email 1.7.7.4 In-Reply-To: <1330579259-3456-1-git-send-email-siddhesh.poyarekar@gmail.com> References: <20120228174049.GA11136@redhat.com> <201202241112.46337.vapier@gentoo.org> <1330579259-3456-1-git-send-email-siddhesh.poyarekar@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is a usability tweak to the earlier patch to mark thread stack vmas based on which vma a task is using as stack. With this patch, each marked stack is also marked with the pid of the task to make things that little bit easier while troubleshooting issues. I have tested to confirm that this does not break current procps behaviour. Thanks Mike Frysinger for the idea. An example output of cat /proc/self/maps with this patch: $ cat /proc/self/maps 00400000-0040b000 r-xp 00000000 fd:00 1048598 /bin/cat 0060a000-0060b000 r--p 0000a000 fd:00 1048598 /bin/cat 0060b000-0060c000 rw-p 0000b000 fd:00 1048598 /bin/cat 02370000-02391000 rw-p 00000000 00:00 0 [heap] 7fc8fbf93000-7fc9023b6000 r--p 00000000 fd:00 1714381 /usr/lib/locale/locale-archive 7fc9023b6000-7fc902561000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7fc902561000-7fc902761000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7fc902761000-7fc902765000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7fc902765000-7fc902767000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7fc902767000-7fc90276c000 rw-p 00000000 00:00 0 7fc90276c000-7fc90278e000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7fc90295f000-7fc902962000 rw-p 00000000 00:00 0 7fc90298c000-7fc90298d000 rw-p 00000000 00:00 0 7fc90298d000-7fc90298e000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7fc90298e000-7fc90298f000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7fc90298f000-7fc902990000 rw-p 00000000 00:00 0 7fff5fb8d000-7fff5fbae000 rw-p 00000000 00:00 0 [stack:2663] 7fff5fbff000-7fff5fc00000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] Signed-off-by: Siddhesh Poyarekar --- Documentation/filesystems/proc.txt | 12 ++++++------ fs/proc/task_mmu.c | 16 ++++++++++++---- fs/proc/task_nommu.c | 5 +++-- include/linux/mm.h | 2 +- mm/memory.c | 13 +++++++------ 5 files changed, 29 insertions(+), 19 deletions(-) diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index e0f9de3..a31434e 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -337,7 +337,7 @@ a8024000-a8027000 rw-p 00000000 00:00 0 a8027000-a8043000 r-xp 00000000 03:00 8317 /lib/ld-linux.so.2 a8043000-a8044000 r--p 0001b000 03:00 8317 /lib/ld-linux.so.2 a8044000-a8045000 rw-p 0001c000 03:00 8317 /lib/ld-linux.so.2 -aff35000-aff4a000 rw-p 00000000 00:00 0 [stack] +aff35000-aff4a000 rw-p 00000000 00:00 0 [stack:1001] ffffe000-fffff000 r-xp 00000000 00:00 0 [vdso] where "address" is the address space in the process that it occupies, "perms" @@ -356,8 +356,8 @@ The "pathname" shows the name associated file for this mapping. If the mapping is not associated with a file: [heap] = the heap of the program - [stack] = the mapping is used as a stack by one - of the threads of the process + [stack:1001] = the mapping is used as a stack by the thread + with tid 1001 [vdso] = the "virtual dynamic shared object", the kernel system call handler @@ -365,9 +365,9 @@ is not associated with a file: The /proc/PID/task/TID/maps is a view of the virtual memory from the viewpoint of the individual tasks of a process. In this file you will see a mapping marked -as [stack] only if that task sees it as a stack. This is a key difference from -the content of /proc/PID/maps, where you will see all mappings that are being -used as stack by all of those tasks. +as [stack:TID] only if that task sees it as a stack. This is a key difference +from the content of /proc/PID/maps, where you will see all mappings that are +being used as stack by all of those tasks. The /proc/PID/smaps is an extension based on maps, showing the memory consumption for each of the process's mappings. For each of mappings there diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index f94a12a..8e32e28 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -262,8 +262,14 @@ show_map_vma(struct seq_file *m, struct vm_area_struct *vma, int is_pid) if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) { name = "[heap]"; - } else if (vm_is_stack(task, vma, is_pid)) { - name = "[stack]"; + } else { + pid_t tid = + vm_is_stack(task, vma, is_pid); + if (tid != 0) { + pad_len_spaces(m, len); + seq_printf(m, "[stack:%d]", + tid); + } } } else { name = "[vdso]"; @@ -1099,8 +1105,10 @@ static int show_numa_map(struct seq_file *m, void *v, int is_pid) seq_path(m, &file->f_path, "\n\t= "); } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) { seq_printf(m, " heap"); - } else if (vm_is_stack(proc_priv->task, vma, is_pid)) { - seq_printf(m, " stack"); + } else { + pid_t tid = vm_is_stack(proc_priv->task, vma, is_pid); + if (tid != 0) + seq_printf(m, " stack:%d", tid); } if (is_vm_hugetlb_page(vma)) diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c index bdfff69..8aaba8c 100644 --- a/fs/proc/task_nommu.c +++ b/fs/proc/task_nommu.c @@ -170,9 +170,10 @@ static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma, pad_len_spaces(m, len); seq_path(m, &file->f_path, ""); } else if (mm) { - if (vm_is_stack(priv->task, vma, is_pid)) + pid_t tid = vm_is_stack(priv->task, vma, is_pid); + if (tid != 0) { pad_len_spaces(m, len); - seq_puts(m, "[stack]"); + seq_printf(m, "[stack:%d]", tid); } } diff --git a/include/linux/mm.h b/include/linux/mm.h index 58d47ae..53c3e75 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1040,7 +1040,7 @@ static inline int stack_guard_page_end(struct vm_area_struct *vma, !vma_growsup(vma->vm_next, addr); } -extern int +extern pid_t vm_is_stack(struct task_struct *task, struct vm_area_struct *vma, int in_group); extern unsigned long move_page_tables(struct vm_area_struct *vma, diff --git a/mm/memory.c b/mm/memory.c index d44b180..2533d9f 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3919,22 +3919,23 @@ void print_vma_addr(char *prefix, unsigned long ip) /* * Check if the vma is being used as a stack. * If is_group is non-zero, check in the entire thread group or else - * just check in the current task. + * just check in the current task. Returns the pid of the task that + * the vma is stack for. */ -int vm_is_stack(struct task_struct *task, - struct vm_area_struct *vma, int in_group) +pid_t vm_is_stack(struct task_struct *task, + struct vm_area_struct *vma, int in_group) { - int ret = 0; + pid_t ret = 0; if (vm_is_stack_for_task(task, vma)) - return 1; + return task->pid; if (in_group) { struct task_struct *t = task; rcu_read_lock(); while_each_thread(task, t) { if (vm_is_stack_for_task(t, vma)) { - ret = 1; + ret = t->pid; goto done; } } -- 1.7.7.4