On 07.02.20 08:58, Michael S. Tsirkin wrote: > On Fri, Feb 07, 2020 at 08:47:14AM +0100, Christian Borntraeger wrote: >> Also adding Cornelia. >> >> >> On 06.02.20 23:17, Michael S. Tsirkin wrote: >>> On Thu, Feb 06, 2020 at 04:12:21PM +0100, Christian Borntraeger wrote: >>>> >>>> >>>> On 06.02.20 15:22, eperezma@xxxxxxxxxx wrote: >>>>> Hi Christian. >>>>> >>>>> Could you try this patch on top of ("38ced0208491 vhost: use batched version by default")? >>>>> >>>>> It will not solve your first random crash but it should help with the lost of network connectivity. >>>>> >>>>> Please let me know how does it goes. >>>> >>>> >>>> 38ced0208491 + this seem to be ok. >>>> >>>> Not sure if you can make out anything of this (and the previous git bisect log) >>> >>> Yes it does - that this is just bad split-up of patches, and there's >>> still a real bug that caused worse crashes :) >>> >>> So I just pushed batch-v4. >>> I expect that will fail, and bisect to give us >>> vhost: batching fetches >>> Can you try that please? >>> >> >> yes. >> >> eccb852f1fe6bede630e2e4f1a121a81e34354ab is the first bad commit >> commit eccb852f1fe6bede630e2e4f1a121a81e34354ab >> Author: Michael S. Tsirkin <mst@xxxxxxxxxx> >> Date: Mon Oct 7 06:11:18 2019 -0400 >> >> vhost: batching fetches >> >> With this patch applied, new and old code perform identically. >> >> Lots of extra optimizations are now possible, e.g. >> we can fetch multiple heads with copy_from/to_user now. >> We can get rid of maintaining the log array. Etc etc. >> >> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> >> >> drivers/vhost/test.c | 2 +- >> drivers/vhost/vhost.c | 39 ++++++++++++++++++++++++++++++++++----- >> drivers/vhost/vhost.h | 4 +++- >> 3 files changed, 38 insertions(+), 7 deletions(-) >> > > > And the symptom is still the same - random crashes > after a bit of traffic, right? random guest crashes after a reboot of the guests. As if vhost would still write into now stale buffers.