Messages in this thread | | | Subject | Re: WARNING in __mmdrop | From | Jason Wang <> | Date | Tue, 23 Jul 2019 21:37:23 +0800 |
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On 2019/7/23 下午6:42, Michael S. Tsirkin wrote: > On Tue, Jul 23, 2019 at 04:42:19PM +0800, Jason Wang wrote: >>> So how about this: do exactly what you propose but as a 2 patch series: >>> start with the slow safe patch, and add then return uaddr optimizations >>> on top. We can then more easily reason about whether they are safe. >> >> If you stick, I can do this. > So I definitely don't insist but I'd like us to get back to where > we know existing code is very safe (if not super fast) and > optimizing from there. Bugs happen but I'd like to see a bisect > giving us "oh it's because of XYZ optimization" and not the > general "it's somewhere within this driver" that we are getting > now.
Syzbot has bisected to the commit of metadata acceleration in fact :)
> > Maybe the way to do this is to revert for this release cycle > and target the next one. What do you think?
I would try to fix the issues consider packed virtqueue which may use this for a good performance number. But if you insist, I'm ok to revert. Or maybe introduce a config option to disable it by default (almost all optimized could be ruled out).
Thanks
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