On Thu, Mar 18, 2010 at 12:23:27AM +0530, Balbir Singh wrote: > * Vivek Goyal <vgoyal@xxxxxxxxxx> [2010-03-17 09:34:07]: > > > > > > > > > root cgroup > > > > ========== > > > > #time dd if=/dev/zero of=/root/zerofile bs=4K count=1M > > > > 4294967296 bytes (4.3 GB) copied, 56.098 s, 76.6 MB/s > > > > > > > > real 0m56.614s > > > > > > > > test1 cgroup with memory limit 100M > > > > =================================== > > > > # time dd if=/dev/zero of=/root/zerofile1 bs=4K count=1M > > > > 4294967296 bytes (4.3 GB) copied, 19.8097 s, 217 MB/s > > > > > > > > real 0m19.992s > > > > > > > > > > This is strange, did you flish the cache between the two runs? > > > NOTE: Since the files are same, we reuse page cache from the > > > other cgroup. > > > > Files are different. Note suffix "1". > > > > Thanks, I'll get the perf output and see what I get. One more thing I noticed and that is, it happens only if we limit the memory of cgroup to 100M. If same cgroup test1 is unlimited memory thing, then it did not happen. I also did not notice this happening on other system where I have 4G of memory. So it also seems to be related with only bigger configurations. Thanks Vivek > > -- > Three Cheers, > Balbir -- 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>