On Fri, Jul 10, 2020 at 7:58 AM Michael S. Tsirkin <mst@xxxxxxxxxx> wrote: > > On Fri, Jul 10, 2020 at 07:39:26AM +0200, Eugenio Perez Martin wrote: > > > > How about playing with the batch size? Make it a mod parameter instead > > > > of the hard coded 64, and measure for all values 1 to 64 ... > > > > > > > > > Right, according to the test result, 64 seems to be too aggressive in > > > the case of TX. > > > > > > > Got it, thanks both! > > In particular I wonder whether with batch size 1 > we get same performance as without batching > (would indicate 64 is too aggressive) > or not (would indicate one of the code changes > affects performance in an unexpected way). > > -- > MST > Hi! Varying batch_size as drivers/vhost/net.c:VHOST_NET_BATCH, and testing the pps as previous mail says. This means that we have either only vhost_net batching (in base testing, like previously to apply this patch) or both batching sizes the same. I've checked that vhost process (and pktgen) goes 100% cpu also. For tx: Batching decrements always the performance, in all cases. Not sure why bufapi made things better the last time. Batching makes improvements until 64 bufs, I see increments of pps but like 1%. For rx: Batching always improves performance. It seems that if we batch little, bufapi decreases performance, but beyond 64, bufapi is much better. The bufapi version keeps improving until I set a batching of 1024. So I guess it is super good to have a bunch of buffers to receive. Since with this test I cannot disable event_idx or things like that, what would be the next step for testing? Thanks! -- Results: # Buf size: 1,16,32,64,128,256,512 # Tx # === # Base 2293304.308,3396057.769,3540860.615,3636056.077,3332950.846,3694276.154,3689820 # Batch 2286723.857,3307191.643,3400346.571,3452527.786,3460766.857,3431042.5,3440722.286 # Batch + Bufapi 2257970.769,3151268.385,3260150.538,3379383.846,3424028.846,3433384.308,3385635.231,3406554.538 # Rx # == # pktgen results (pps) 1223275,1668868,1728794,1769261,1808574,1837252,1846436 1456924,1797901,1831234,1868746,1877508,1931598,1936402 1368923,1719716,1794373,1865170,1884803,1916021,1975160 # Testpmd pps results 1222698.143,1670604,1731040.6,1769218,1811206,1839308.75,1848478.75 1450140.5,1799985.75,1834089.75,1871290,1880005.5,1934147.25,1939034 1370621,1721858,1796287.75,1866618.5,1885466.5,1918670.75,1976173.5,1988760.75,1978316 pktgen was run again for rx with 1024 and 2048 buf size, giving 1988760.75 and 1978316 pps. Testpmd goes the same way.
