On Wed, Jun 29, 2022 at 11:16:10AM -0600, Jens Axboe wrote: > Not sure what Christoph change you are referring to, but all the ones > that I did to improve the init side were all backed by numbers I ran at > that time (and most/all of the commit messages will have that data). So > yes, it is indeed still very noticeable. Maybe not at 100K IOPS, but at > 10M on a core it most certainly is. I was referring to 609be1066731fea86436f5f91022f82e592ab456. You signed off on it, you must remember it...? > I'm all for having solid and maintainable code, obviously, but frivolous > bloating of structures and more expensive setup cannot be hand waved > away with "it doesn't matter if we touch 3 or 6 cachelines" because we > obviously have a disagreement on that. I wouldn't propose inflating struct _bio_ like that. But Jens, to be blunt - I know we have different priorities in the way we write code. Your writeback throttling code was buggy for _ages_ and I had users hitting deadlocks there that I pinged you about, and I could not make heads or tails of how that code was supposed to work and not for lack of time spent trying! You should be well aware that I care about performance too - I was the one who pushed through the patches to not separately allocate mempools and biosets, and a lot of the work I did ages ago was specifically to work towards getting rif of the counting segments pass (work I believe Ming completed); that was a _major_ chunk of cpu time in any block layer profile I've looked at. So sure, tell me I don't care about performance enough. *sigh* -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel
