On Wed, Feb 27, 2013 at 05:58:37PM +1030, Rusty Russell wrote: > Paolo Bonzini <pbonzini@xxxxxxxxxx> writes: > > Il 24/02/2013 23:12, Michael S. Tsirkin ha scritto: > >> On Tue, Feb 19, 2013 at 06:26:20PM +1030, Rusty Russell wrote: > >>> virtio_scsi can really use this, to avoid the current hack of copying > >>> the whole sg array. Some other things get slightly neater, too. > >>> > >>> Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx> > >> > >> Hmm, this makes add_buf a bit slower. virtio_test results > >> (I'll send a patch to update the test shortly): > >> > >> Before: > >> 0.09user 0.01system 0:00.12elapsed 91%CPU (0avgtext+0avgdata 480maxresident)k > >> 0inputs+0outputs (0major+145minor)pagefaults 0swaps > >> > >> After: > >> 0.11user 0.01system 0:00.13elapsed 90%CPU (0avgtext+0avgdata 480maxresident)k > >> 0inputs+0outputs (0major+145minor)pagefaults 0swaps > > > > Not unexpected at all... :( > > > > Some of it can be recovered, but if it's 20% I doubt all of it. So my > > patches were not premature optimization; you really can take just two > > among speed, flexibility, and having a nice API. > > The error bars on this are far too large to say "20%". > > Here are my numbers, using 50 runs of: > time tools/virtio/vringh_test --indirect --eventidx --parallel and > stats --trim-outliers: > > Baseline (before add_sgs): > 2.840000-3.040000(2.927292)user > > After add_sgs: > 2.970000-3.150000(3.053750)user > > After simplifying add_buf a little: > 2.950000-3.210000(3.081458)user > > After inlining virtqueue_add/vring_add_indirect: > 2.920000-3.150000(3.026875)user > > After passing in iteration functions (chained vs unchained): > 2.760000-2.970000(2.883542)user > > After removing the now-unnecessary chain-cleaning in add_buf: > 2.660000-2.830000(2.753542)user > > Any questions? > Rusty. Sorry, so which patches are included in the last stage? Something I didn't make clear: I tested 2/16 (the patch I replied to). -- MST _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
