On Tue, Jan 07, 2020 at 12:34:50PM +0100, Christian Borntraeger wrote: > > > On 07.01.20 10:39, Michael S. Tsirkin wrote: > > On Tue, Jan 07, 2020 at 09:59:16AM +0100, Christian Borntraeger wrote: > >> > >> > >> 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 > >> > > > > Not sure why but I pushed a wrong commit. Sorry. Should be good now. > > > > during bisect: > > drivers/vhost/vhost.c: In function ‘vhost_get_vq_desc_batch’: > drivers/vhost/vhost.c:2634:8: error: ‘id’ undeclared (first use in this function); did you mean ‘i’? > 2634 | ret = id; > | ^~ > | i > > I changed that to i > > > The last step then gave me (on commit 50297a8480b439efc5f3f23088cb2d90b799acef vhost: use batched version by default) > net enc1: Unexpected TXQ (0) queue failure: -5 > in the guest. > > bisect log so far: > [cborntra@m83lp52 linux]$ git bisect log > git bisect start > # bad: [3131e79bb9e9892a5a6bd33513de9bc90b20e867] vhost: use vhost_desc instead of vhost_log > git bisect bad 3131e79bb9e9892a5a6bd33513de9bc90b20e867 > # good: [d1281e3a562ec6a08f944a876481dd043ba739b9] virtio-blk: remove VIRTIO_BLK_F_SCSI support > git bisect good d1281e3a562ec6a08f944a876481dd043ba739b9 > # good: [5b00aab5b6332a67e32dace1dcd3a198ab94ed56] vhost: option to fetch descriptors through an independent struct > git bisect good 5b00aab5b6332a67e32dace1dcd3a198ab94ed56 > # good: [5b00aab5b6332a67e32dace1dcd3a198ab94ed56] vhost: option to fetch descriptors through an independent struct > git bisect good 5b00aab5b6332a67e32dace1dcd3a198ab94ed56 > # bad: [1414d7ee3d10d2ec2bc4ee652d1d90ec91da1c79] vhost: batching fetches > git bisect bad 1414d7ee3d10d2ec2bc4ee652d1d90ec91da1c79 > > I pushed batched-v3 - same head but bisect should work now. -- MST
