On Thu, Mar 18, 2010 at 12:47:43AM +0530, Balbir Singh wrote: > * Vivek Goyal <vgoyal@xxxxxxxxxx> [2010-03-17 09:34:07]: > > > On Wed, Mar 17, 2010 at 05:24:28PM +0530, Balbir Singh wrote: > > > * Vivek Goyal <vgoyal@xxxxxxxxxx> [2010-03-15 13:19:21]: > > > > > > > On Mon, Mar 15, 2010 at 01:12:09PM -0400, Vivek Goyal wrote: > > > > > On Mon, Mar 15, 2010 at 12:26:37AM +0100, Andrea Righi wrote: > > > > > > Control the maximum amount of dirty pages a cgroup can have at any given time. > > > > > > > > > > > > Per cgroup dirty limit is like fixing the max amount of dirty (hard to reclaim) > > > > > > page cache used by any cgroup. So, in case of multiple cgroup writers, they > > > > > > will not be able to consume more than their designated share of dirty pages and > > > > > > will be forced to perform write-out if they cross that limit. > > > > > > > > > > > > > > > > For me even with this version I see that group with 100M limit is getting > > > > > much more BW. > > > > > > > > > > root cgroup > > > > > ========== > > > > > #time dd if=/dev/zero of=/root/zerofile bs=4K count=1M > > > > > 4294967296 bytes (4.3 GB) copied, 55.7979 s, 77.0 MB/s > > > > > > > > > > real 0m56.209s > > > > > > > > > > test1 cgroup with memory limit of 100M > > > > > ====================================== > > > > > # time dd if=/dev/zero of=/root/zerofile1 bs=4K count=1M > > > > > 4294967296 bytes (4.3 GB) copied, 20.9252 s, 205 MB/s > > > > > > > > > > real 0m21.096s > > > > > > > > > > Note, these two jobs are not running in parallel. These are running one > > > > > after the other. > > > > > > > > > > > The data is not always repeatable at my end. Are you able to modify > the order and get repeatable results? > > In fact, I saw > > for cgroup != root > ------------------ > 4294967296 bytes (4.3 GB) copied, 120.359 s, 35.7 MB/s > > for cgroup = root > ----------------- > 4294967296 bytes (4.3 GB) copied, 84.504 s, 50.8 MB/s > > This is without the patches applied. I lost the access to the big configuration machine but on that machine I could reproduce it all the time. But on smaller machine (4core, 4G), I could not. I will do some more tests later. Vivek -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>