[lkml]   [2003]   [Jun]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] Remove page_table_lock from vma manipulations
On Wed, Jun 04, 2003 at 05:30:25PM -0500, Dave McCracken wrote:
> After more careful consideration, I don't see any reasons why
> page_table_lock is necessary for dealing with vmas. I found one spot in
> swapoff, but it was easily changed to mmap_sem. I've beat on this code and
> mjb has beat on this code with no problems. Here's the patch to remove it.
> Feel free to poke holes in it.

shrink_list() calls try_to_unmap() under pte_chain_lock(page), and
hence try_to_unmap() cannot sleep. Furthermore try_to_unmap() calls
find_vma() under the sole protection of
spin_trylock(&mm->page_table_lock), which I don't see changed to a
read_trylock(&mm->mmap_sem) here.

Hence, this is racy.

-- wli
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:36    [W:0.091 / U:0.412 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site