On Jul 19, 2022 / 17:31, Bjorn Helgaas wrote: > On Tue, Jul 19, 2022 at 04:50:36AM +0000, Shinichiro Kawasaki wrote: > > On Jun 15, 2022 / 17:16, Keith Busch wrote: > > > On Wed, Jun 15, 2022 at 02:47:27PM -0500, Bjorn Helgaas wrote: > > > > On Tue, Jun 14, 2022 at 04:00:45AM +0000, Shinichiro Kawasaki wrote: > > > > > > > > > > Yeah, this WARN is confusing for us then it would be valuable to > > > > > test by blktests not to repeat it. One point I wonder is: which test > > > > > group the test case will it fall in? The nvme group could be the > > > > > group to add, probably. > > > > > > > > > > Another point I wonder is other kernel test suite than blktests. > > > > > Don't we have more appropriate test suite to check PCI device > > > > > rescan/remove race ? Such a test sounds more like a PCI bus > > > > > sub-system test than block/storage test. > > > > > > > > I'm not aware of such a test, but it would be nice to have one. > > > > > > > > Can you share your qemu config so I can reproduce this locally? > > > > > > > > Thanks for finding and reporting this! > > > > > > This ought to be reproducible with any pci device that can be > > > removed. Since we initially observed with nvme, you can try with > > > such a device. A quick way to get one appearing in qemu is to add > > > parameters: > > > > > > -drive id=n,if=none,file=null-co://,format=raw \ > > > -device nvme,serial=foobar,drive=n > > > > Did you have chance to reproduce the WARN? Recently, it was reported > > again [1] and getting attention. > > I have not paid any attention to this yet. From what I can tell, the > problem was discovered by a test case (i.e., not reported by a > real-world user), it is not a recent regression, we haven't identified > a commit that introduced the problem, and we do not have a potential > fix for it. Obviously it needs to be fixed and I'm not trying to > minimize the problem; I just want to calibrate it against everything > else. Bjorn, thank you for sharing your view, which sounds reasonable for me. -- Shin'ichiro Kawasaki
