On Wed, Mar 05, 2025 at 02:53:07PM +0530, Malladi, Meghana wrote: > Hi Dan, > > On 3/3/2025 7:38 PM, Dan Carpenter wrote: > > What I mean is just compile the .o file with and without the unlikely(). > > $ md5sum drivers/net/ethernet/ti/icssg/icssg_common. o* > > 2de875935222b9ecd8483e61848c4fc9 drivers/net/ethernet/ti/icssg/ > > icssg_common. o. annotation 2de875935222b9ecd8483e61848c4fc9 > > ZjQcmQRYFpfptBannerStart > > This message was sent from outside of Texas Instruments. > > Do not click links or open attachments unless you recognize the source > > of this email and know the content is safe. > > Report Suspicious > > <https://us-phishalarm-ewt.proofpoint.com/EWT/v1/G3vK! > > uldq3TevVoc7KuXEXHnDf- TXtuZ0bON9iO0jTE7PyIS1jjfs_CzpvIiMi93PVt0MVDzjHGQSK__vY_-6rO7q86rFmBMGW4SSqK5pvNE$> > > ZjQcmQRYFpfptBannerEnd > > > > What I mean is just compile the .o file with and without the unlikely(). > > > > $ md5sum drivers/net/ethernet/ti/icssg/icssg_common.o* > > 2de875935222b9ecd8483e61848c4fc9 drivers/net/ethernet/ti/icssg/icssg_common.o.annotation > > 2de875935222b9ecd8483e61848c4fc9 drivers/net/ethernet/ti/icssg/icssg_common.o.no_anotation > > > > Generally the rule is that you should leave likely/unlikely() annotations > > out unless it's going to make a difference on a benchmark. I'm not going > > to jump down people's throat about this, and if you want to leave it, > > it's fine. But it just struct me as weird so that's why I commented on > > it. > > > > I have done some performance tests to see if unlikely() is gonna make any > impact and I see around ~9000 pps and 6Mbps drop without unlikely() for > small packet sizes (60 Bytes) > > You can see summary of the tests here: > > packet size with unlikely(pps) without unlikely(pps) regression > > 60 462377 453251 9126 > > 80 403020 399372 3648 > > 96 402059 396881 5178 > > 120 392725 391312 4413 > > 140 327706 327099 607 > > packet size with unlikely(Mbps) without unlikely(Mbps) regression > > 60 311 305 6 > > 80 335 332 3 > > 96 386 381 5 > > 120 456 451 5 > > 140 430 429 1 > > For more details on the logs, please refer:https://gist.github.com/MeghanaMalladiTI/cc6cc7709791376cb486eb1222de67be > Huh. That's very interesting. Fine, then. regards, dan carpenter
