lkml.org 
[lkml]   [2003]   [Feb]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: buffer leakage in kernel?


On Mon, 27 Jan 2003, Andrew Morton wrote:

>
> I suspect what is happening is that you've managed to find a code path in
> which the kernel is allocating lots of memory in a mode in which it cannot
> run effective page reclaim. This would be more likely to be true if you only
> see the failures when writing.
>
> It would help if you could change mm/vmscan.c:try_to_free_pages_zone()
> thusly:
>
> /*
> * Hmm.. Cache shrink failed - time to kill something?
> * Mhwahahhaha! This is the part I really like. Giggle.
> */
> + show_stack(0);
> out_of_memory();
> return 0;
> }
>
> and pass the resulting log output through ksyoops.
>
> And here's a protopatch to teach the kernel to make sure that there's a
> decent amount of free memory before it goes and performs GFP_NOFS pagecache
> allocations:
>
> diff -puN fs/buffer.c~a fs/buffer.c
> --- 24/fs/buffer.c~a 2003-01-27 12:28:02.000000000 -0800
> +++ 24-akpm/fs/buffer.c 2003-01-27 12:28:23.000000000 -0800
> @@ -2112,6 +2112,8 @@ int generic_direct_IO(int rw, struct ino
> for (i = 0; i < nr_blocks; i++, blocknr++) {
> struct buffer_head bh;
>
> + try_to_free_pages(GFP_KERNEL);
> +
> bh.b_state = 0;
> bh.b_dev = inode->i_dev;
> bh.b_size = blocksize;
>
>
> If that sheds no light, please send me the app and I'll see if I can
> reproduce it. Thanks.
>
>

I have not yet tried that because of the lack of time. Instead I installed
2.4.21-pre4. The problem seems to be fixed there.


Roman

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

\
 
 \ /
  Last update: 2005-03-22 13:32    [W:0.078 / U:2.380 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site