On 06.01.20 11:50, Michael S. Tsirkin wrote: > On Wed, Dec 18, 2019 at 04:59:02PM +0100, Christian Borntraeger wrote: >> On 18.12.19 16:10, Michael S. Tsirkin wrote: >>> On Wed, Dec 18, 2019 at 03:43:43PM +0100, Christian Borntraeger wrote: >>>> Michael, >>>> >>>> with >>>> commit db7286b100b503ef80612884453bed53d74c9a16 (refs/bisect/skip-db7286b100b503ef80612884453bed53d74c9a16) >>>> vhost: use batched version by default >>>> plus >>>> commit 6bd262d5eafcdf8cdfae491e2e748e4e434dcda6 (HEAD, refs/bisect/bad) >>>> Revert "vhost/net: add an option to test new code" >>>> to make things compile (your next tree is not easily bisectable, can you fix that as well?). >>> >>> I'll try. >>> >>>> >>>> I get random crashes in my s390 KVM guests after reboot. >>>> Reverting both patches together with commit decd9b8 "vhost: use vhost_desc instead of vhost_log" to >>>> make it compile again) on top of linux-next-1218 makes the problem go away. >>>> >>>> Looks like the batched version is not yet ready for prime time. Can you drop these patches until >>>> we have fixed the issues? >>>> >>>> Christian >>>> >>> >>> Will do, thanks for letting me know. >> >> I have confirmed with the initial reporter (internal test team) that <driver name='qemu'/> >> with a known to be broken linux next kernel also fixes the problem, so it is really the >> vhost changes. > > OK I'm back and trying to make it more bisectable. > > I pushed a new tag "batch-v2". > It's same code but with this bisect should get more information. I get the following with this tag drivers/vhost/net.c: In function ‘vhost_net_tx_get_vq_desc’: drivers/vhost/net.c:574:7: error: implicit declaration of function ‘vhost_get_vq_desc_batch’; did you mean ‘vhost_get_vq_desc’? [-Werror=implicit-function-declaration] 574 | r = vhost_get_vq_desc_batch(tvq, tvq->iov, ARRAY_SIZE(tvq->iov), | ^~~~~~~~~~~~~~~~~~~~~~~ | vhost_get_vq_desc