lkml.org 
[lkml]   [2007]   [Jul]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectFull buffer cache not working properly
I run several times the following test and what I've seen is that when 
the buffer cache becomes full, unneeded dirty buffer heads are not evicted
and no other memory allocation can happen (including reading a block
from the disk to the buffer cache). Should this happen?
Here's the code that reproduces this issue:

for(i = 0; i < get_capacity(bdev->bd_disk)/8; i++) {
bh = __bread(bdev, i, PAGE_SIZE);
lock_buffer(bh);
memset(bh->b_data, 0, PAGE_SIZE);
set_buffer_dirty(bh);
unlock_buffer(bh);
__brelse(bh);
}

I added some printks printing the buffer head's reference counter: after
the '__bread' ref count is 2, after '__brelse' ref count is 1. Shouldn't
these
numbers be 1 and 0 respectively? I added an extra 'put_bh' before (or
after) the '__brelse' but I get a BUG().
-
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: 2007-07-13 04:01    [W:0.045 / U:0.144 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site