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. -- Jens Axboe