[TLDR: I'm adding the regression report below to regzbot, the Linux kernel regression tracking bot; all text you find below is compiled from a few templates paragraphs you might have encountered already already from similar mails.] On 07.03.22 19:15, Larkin Lowrey wrote: > I am seeing a 'check' speed regression between kernels 5.15 and 5.16. > One host with a 20 drive array went from 170MB/s to 11MB/s. Another host > with a 15 drive array went from 180MB/s to 43MB/s. In both cases the > arrays are almost completely idle. I can flip between the two kernels > with no other changes and observe the performance changes. > > Is this a known issue? Hi, this is your Linux kernel regression tracker. Thanks for the report. CCing the regression mailing list, as it should be in the loop for all regressions, as explained here: https://www.kernel.org/doc/html/latest/admin-guide/reporting-issues.html To be sure below issue doesn't fall through the cracks unnoticed, I'm adding it to regzbot, my Linux kernel regression tracking bot: #regzbot ^introduced v5.15..v5.16 #regzbot title md: Raid6 check performance regression #regzbot ignore-activity If it turns out this isn't a regression, free free to remove it from the tracking by sending a reply to this thread containing a paragraph like "#regzbot invalid: reason why this is invalid" (without the quotes). Reminder for developers: when fixing the issue, please add a 'Link:' tags pointing to the report (the mail quoted above) using lore.kernel.org/r/, as explained in 'Documentation/process/submitting-patches.rst' and 'Documentation/process/5.Posting.rst'. Regzbot needs them to automatically connect reports with fixes, but they are useful in general, too. I'm sending this to everyone that got the initial report, to make everyone aware of the tracking. I also hope that messages like this motivate people to directly get at least the regression mailing list and ideally even regzbot involved when dealing with regressions, as messages like this wouldn't be needed then. And don't worry, if I need to send other mails regarding this regression only relevant for regzbot I'll send them to the regressions lists only (with a tag in the subject so people can filter them away). With a bit of luck no such messages will be needed anyway. Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) P.S.: As the Linux kernel's regression tracker I'm getting a lot of reports on my table. I can only look briefly into most of them and lack knowledge about most of the areas they concern. I thus unfortunately will sometimes get things wrong or miss something important. I hope that's not the case here; if you think it is, don't hesitate to tell me in a public reply, it's in everyone's interest to set the public record straight. -- Additional information about regzbot: If you want to know more about regzbot, check out its web-interface, the getting start guide, and the references documentation: https://linux-regtracking.leemhuis.info/regzbot/ https://gitlab.com/knurd42/regzbot/-/blob/main/docs/getting_started.md https://gitlab.com/knurd42/regzbot/-/blob/main/docs/reference.md The last two documents will explain how you can interact with regzbot yourself if your want to. Hint for reporters: when reporting a regression it's in your interest to CC the regression list and tell regzbot about the issue, as that ensures the regression makes it onto the radar of the Linux kernel's regression tracker -- that's in your interest, as it ensures your report won't fall through the cracks unnoticed. Hint for developers: you normally don't need to care about regzbot once it's involved. Fix the issue as you normally would, just remember to include 'Link:' tag in the patch descriptions pointing to all reports about the issue. This has been expected from developers even before regzbot showed up for reasons explained in 'Documentation/process/submitting-patches.rst' and 'Documentation/process/5.Posting.rst'.
