Re: [PATCH] exec: remove page_table_lock for mm counters inacct_arg_size()

From: Oleg Nesterov
Date: Thu Jul 14 2011 - 09:20:42 EST


On 07/14, Frantisek Hrbata wrote:
>
> Commit 172703b mm: delete non-atomic mm counter implementation
> removed non-atomic mm counters implementation. I think there is no need to hold
> page_table_lock for add_mm_counter() when the splitted page table locks are not
> used. This patch removes the locking.
>
> Signed-off-by: Frantisek Hrbata <fhrbata@xxxxxxxxxx>
> ---
> fs/exec.c | 6 ------
> 1 files changed, 0 insertions(+), 6 deletions(-)
>
> diff --git a/fs/exec.c b/fs/exec.c
> index 6075a1e..e6fc5e1 100644
> --- a/fs/exec.c
> +++ b/fs/exec.c
> @@ -182,13 +182,7 @@ static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
>
> bprm->vma_pages = pages;
>
> -#ifdef SPLIT_RSS_COUNTING
> add_mm_counter(mm, MM_ANONPAGES, diff);
> -#else
> - spin_lock(&mm->page_table_lock);
> - add_mm_counter(mm, MM_ANONPAGES, diff);
> - spin_unlock(&mm->page_table_lock);
> -#endif

Heh. Thanks Frantisek, you are right. But this patch is already in mm-tree,
fs-execc-acct_arg_size-ptl-is-no-longer-needed-for-add_mm_counter.patch

Oleg.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/