lkml.org 
[lkml]   [2009]   [Jun]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: + procfs-provide-stack-information-for-threads-v08.patch added to -mm tree
On Mon, Jun 15, 2009 at 03:02:05PM -0700, akpm@linux-foundation.org wrote:
> procfs-provide-stack-information-for-threads-v08.patch
> --- a/fs/proc/array.c~procfs-provide-stack-information-for-threads-v08

> +++ a/fs/proc/array.c
> @@ -321,6 +321,54 @@ static inline void task_context_switch_c
> p->nivcsw);
> }
>
> +static inline unsigned long get_stack_usage_in_bytes(struct vm_area_struct *vma,
> + struct task_struct *p)
> +{
> + unsigned long i;
> + struct page *page;
> + unsigned long stkpage;
> +
> + stkpage = KSTK_ESP(p) & PAGE_MASK;
> +
> +#ifdef CONFIG_STACK_GROWSUP
> + for (i = vma->vm_end; i-PAGE_SIZE > stkpage; i -= PAGE_SIZE) {
> +
> + page = follow_page(vma, i-PAGE_SIZE, 0);

How can this work?

If stack page got swapped out, you'll get smaller than actual result.

> +
> + if (!IS_ERR(page) && page)
> + break;
> + }
> + return i - (p->stack_start & PAGE_MASK);
> +#else
> + for (i = vma->vm_start; i+PAGE_SIZE <= stkpage; i += PAGE_SIZE) {
> +
> + page = follow_page(vma, i, 0);
> +
> + if (!IS_ERR(page) && page)
> + break;
> + }
> + return (p->stack_start & PAGE_MASK) - i + PAGE_SIZE;
> +#endif
> +}
> +
> +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);
> + }
> +}


\
 
 \ /
  Last update: 2009-06-16 00:37    [W:0.059 / U:0.236 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site