Jens Axboe <axboe@xxxxxxxxx> writes: > On 12/6/18 12:27 PM, Jeff Moyer wrote: >> Jens Axboe <axboe@xxxxxxxxx> writes: >> >>> It's 192 bytes, fairly substantial. Most items don't need to be cleared, >>> especially not upfront. Clear the ones we do need to clear, and leave >>> the other ones for setup when the iocb is prepared and submitted. >> >> What performance gains do you see from this? > > Before this, I had 1% in memset doing high IOPS. With it, that's gone. > 1% is a lot, when you have just one thread doing everything from submission > to completion. I'm used to customers complaining about fractions of a percent, so I get it. :-) I just wanted to know we had some measurable impact, as I've seen bugs crop up from code like this in the past. Thanks! Jeff
