On Tue, 18 Sep 2012, Jeff Moyer wrote: > Mikulas Patocka <mpatocka@xxxxxxxxxx> writes: > > > Hi Jeff > > > > Thanks for testing. > > > > It would be interesting ... what happens if you take the patch 3, leave > > "struct percpu_rw_semaphore bd_block_size_semaphore" in "struct > > block_device", but remove any use of the semaphore from fs/block_dev.c? - > > will the performance be like unpatched kernel or like patch 3? It could be > > that the change in the alignment affects performance on your CPU too, just > > differently than on my CPU. > > I'll give it a try and report back. > > > What is the CPU model that you used for testing? > > http://ark.intel.com/products/53570/Intel-Xeon-Processor-E7-2860-%2824M-Cache-2_26-GHz-6_40-GTs-Intel-QPI%29 > > Cheers, > Jeff BTW. why did you use just 4 processes? - the processor has 10 cores and 20 threads (so theoretically, you could run 20 processes bound on a single numa node). Were the results not stable with more than 4 processes? Mikulas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
