"Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote on 06/07/2011 09:38:30 PM: > > This is on top of the patches applied by Rusty. > > > > Warning: untested. Posting now to give people chance to > > comment on the API. > > OK, this seems to have survived some testing so far, > after I dropped patch 4 and fixed build for patch 3 > (build fixup patch sent in reply to the original). > > I'll be mostly offline until Sunday, would appreciate > testing reports. Hi Michael, I ran the latest patches with 1K I/O (guest->local host) and the results are (60 sec run for each test case): ______________________________ #sessions BW% SD% ______________________________ 1 -25.6 47.0 2 -29.3 22.9 4 .8 1.6 8 1.6 0 16 -1.6 4.1 32 -5.3 2.1 48 11.3 -7.8 64 -2.8 .7 96 -6.2 .6 128 -10.6 12.7 ______________________________ BW: -4.8 SD: 5.4 I tested it again to see if the regression is fleeting (since the numbers vary quite a bit for 1K I/O even between guest-> local host), but: ______________________________ #sessions BW% SD% ______________________________ 1 14.0 -17.3 2 19.9 -11.1 4 7.9 -15.3 8 9.6 -13.1 16 1.2 -7.3 32 -.6 -13.5 48 -28.7 10.0 64 -5.7 -.7 96 -9.4 -8.1 128 -9.4 .7 ______________________________ BW: -3.7 SD: -2.0 With 16K, there was an improvement in SD, but higher sessions seem to slightly degrade BW/SD: ______________________________ #sessions BW% SD% ______________________________ 1 30.9 -25.0 2 16.5 -19.4 4 -1.3 7.9 8 1.4 6.2 16 3.9 -5.4 32 0 4.3 48 -.5 .1 64 32.1 -1.5 96 -2.1 23.2 128 -7.4 3.8 ______________________________ BW: 5.0 SD: 7.5 Thanks, - KK -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html