Re: Memory pressure handling with iSCSI

On Tue, 2005-07-26 at 16:07 -0700, Andrew Morton wrote:

Badari Pulavarty [off-list ref] wrote:

quoted

Here is the data with 5 ext2 filesystems. I also collected /proc/meminfo
every 5 seconds. As you can see, we seem to dirty 6GB of data in 20
seconds of starting the test. I am not sure if its bad, since we have
lots of free memory..

It's bad.  The logic in balance_dirty_pages() should block those write()
callers as soon as we hit 40% dirty memory or whatever is in
/proc/sys/vm/dirty_ratio.  So something is horridly busted.

Can you try reducing the number of filesystems even further?

Single ext2 filesystem. We still dirty pretty quickly (data collected
every 5 seconds).

 # grep Dirty OUT
Dirty:             312 kB
Dirty:         1121852 kB
Dirty:         2896952 kB
Dirty:         4344564 kB
Dirty:         5310856 kB
Dirty:         5507812 kB
Dirty:         5714884 kB
Dirty:         5865132 kB
Dirty:         6004276 kB
Dirty:         6206544 kB
Dirty:         6380524 kB
Dirty:         6583200 kB
Dirty:         6727296 kB
Dirty:         6708564 kB
Dirty:         6733768 kB
Dirty:         6737868 kB

Thanks,
Badari

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>