On 26.09.23 15:04, Michael Roth wrote: > On Sun, Sep 03, 2023 at 06:13:38PM -0400, Michael S. Tsirkin wrote: >> virtio_net: merge dma operations when filling mergeable buffers > > This ^ patch (upstream commit 295525e29a) seems to cause a > network-related regression when using SWIOTLB in the guest. I noticed > this initially testing SEV guests, which use SWIOTLB by default, but > it can also be seen with normal guests when forcing SWIOTLB via > swiotlb=force kernel cmdline option. I see it with both 6.6-rc1 and > 6.6-rc2 (haven't tried rc3 yet, but don't see any related changes > there), and reverting 714073495f seems to avoid the issue. > > Steps to reproduce: > > [...] Thanks for the report. To be sure the issue doesn't fall through the cracks unnoticed, I'm adding it to regzbot, the Linux kernel regression tracking bot: #regzbot ^introduced 295525e29a #regzbot title virtio: network-related regression when using SWIOTLB in the guest #regzbot ignore-activity This isn't a regression? This issue or a fix for it are already discussed somewhere else? It was fixed already? You want to clarify when the regression started to happen? Or point out I got the title or something else totally wrong? Then just reply and tell me -- ideally while also telling regzbot about it, as explained by the page listed in the footer of this mail. Developers: When fixing the issue, remember to add 'Link:' tags pointing to the report (the parent of this mail). See page linked in footer for details. Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) -- Everything you wanna know about Linux kernel regression tracking: https://linux-regtracking.leemhuis.info/about/#tldr That page also explains what to do if mails like this annoy you.
