| Message ID | 20220408223443.3303509-1-song@kernel.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | vmalloc: bpf: introduce VM_ALLOW_HUGE_VMAP | expand |
Hi, this is your Linux kernel regression tracker. On 09.04.22 00:34, Song Liu wrote: > Enabling HAVE_ARCH_HUGE_VMALLOC on x86_64 and use it for bpf_prog_pack has > caused some issues [1], as many users of vmalloc are not yet ready to > handle huge pages. To enable a more smooth transition to use huge page > backed vmalloc memory, this set replaces VM_NO_HUGE_VMAP flag with an new > opt-in flag, VM_ALLOW_HUGE_VMAP. More discussions about this topic can be > found at [2]. > > Patch 1 removes VM_NO_HUGE_VMAP and adds VM_ALLOW_HUGE_VMAP. > Patch 2 uses VM_ALLOW_HUGE_VMAP in bpf_prog_pack. > > [1] https://lore.kernel.org/lkml/20220204185742.271030-1-song@kernel.org/ > [2] https://lore.kernel.org/linux-mm/20220330225642.1163897-1-song@kernel.org/ These patches apparently fix a regression (one that's mentioned in your [2]) that I tracked. Hence in the next iteration of your patches could you please instead add a 'Link:' tag pointing to the report for anyone wanting to look into the backstory in the future, as explained in 'Documentation/process/submitting-patches.rst' and 'Documentation/process/5.Posting.rst'? E.g. like this: "Link: https://lore.kernel.org/netdev/14444103-d51b-0fb3-ee63-c3f182f0b546@molgen.mpg.de/" Not totally sure, but I guess it needs a Fixes tag as well specifying the change that cause this regression (that's "fac54e2bfb5b"). The documents mentioned above explain this, too. A "Reported-by" might be appropriate as well. In anyone wonders why I care: there are internal and publicly used tools and scripts out there that reply on proper "Link" tags. I don't known how many, but there is at least one public tool I'm running that cares: regzbot, my regression tracking bot, which I use to track Linux kernel regressions and generate the regression reports sent to Linus. Proper "Link:" tags allow the bot to automatically connect regression reports with fixes being posted or applied to resolve the particular regression -- which makes regression tracking a whole lot easier and feasible for the Linux kernel. That's why it's a great help for me if people set proper "Link" tags. While at it, let me tell regzbot about this thread: #regzbot ^backmonitor: https://lore.kernel.org/netdev/14444103-d51b-0fb3-ee63-c3f182f0b546@molgen.mpg.de/ 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.
> On Apr 9, 2022, at 4:43 AM, Thorsten Leemhuis <regressions@leemhuis.info> wrote: > > Hi, this is your Linux kernel regression tracker. > > On 09.04.22 00:34, Song Liu wrote: >> Enabling HAVE_ARCH_HUGE_VMALLOC on x86_64 and use it for bpf_prog_pack has >> caused some issues [1], as many users of vmalloc are not yet ready to >> handle huge pages. To enable a more smooth transition to use huge page >> backed vmalloc memory, this set replaces VM_NO_HUGE_VMAP flag with an new >> opt-in flag, VM_ALLOW_HUGE_VMAP. More discussions about this topic can be >> found at [2]. >> >> Patch 1 removes VM_NO_HUGE_VMAP and adds VM_ALLOW_HUGE_VMAP. >> Patch 2 uses VM_ALLOW_HUGE_VMAP in bpf_prog_pack. >> >> [1] https://lore.kernel.org/lkml/20220204185742.271030-1-song@kernel.org/ >> [2] https://lore.kernel.org/linux-mm/20220330225642.1163897-1-song@kernel.org/ > > These patches apparently fix a regression (one that's mentioned in your > [2]) that I tracked. Hence in the next iteration of your patches could > you please instead add a 'Link:' tag pointing to the report for anyone > wanting to look into the backstory in the future, as explained in > 'Documentation/process/submitting-patches.rst' and > 'Documentation/process/5.Posting.rst'? E.g. like this: > > "Link: > https://lore.kernel.org/netdev/14444103-d51b-0fb3-ee63-c3f182f0b546@molgen.mpg.de/" > > Not totally sure, but I guess it needs a Fixes tag as well specifying > the change that cause this regression (that's "fac54e2bfb5b"). The > documents mentioned above explain this, too. A "Reported-by" might be > appropriate as well. > > In anyone wonders why I care: there are internal and publicly used tools > and scripts out there that reply on proper "Link" tags. I don't known > how many, but there is at least one public tool I'm running that cares: > regzbot, my regression tracking bot, which I use to track Linux kernel > regressions and generate the regression reports sent to Linus. Proper > "Link:" tags allow the bot to automatically connect regression reports > with fixes being posted or applied to resolve the particular regression > -- which makes regression tracking a whole lot easier and feasible for > the Linux kernel. That's why it's a great help for me if people set > proper "Link" tags. > > While at it, let me tell regzbot about this thread: > #regzbot ^backmonitor: > https://lore.kernel.org/netdev/14444103-d51b-0fb3-ee63-c3f182f0b546@molgen.mpg.de/ > > 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. Thanks for the reminder. I will add the Fixes tag, and try to work with regzbot. Song