On 05.07.23 09:08, Greg KH wrote: > On Tue, Jul 04, 2023 at 01:22:54PM -0700, Suren Baghdasaryan wrote: >> On Tue, Jul 4, 2023 at 9:18 AM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: >>> On Tue, 4 Jul 2023 09:00:19 +0100 Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: >>>>>>>> Thanks! I'll investigate this later today. After discussing with >>>>>>>> Andrew, we would like to disable CONFIG_PER_VMA_LOCK by default until >>>>>>>> the issue is fixed. I'll post a patch shortly. >>>>>>> >>>>>>> Posted at: https://lore.kernel.org/all/20230703182150.2193578-1-surenb@xxxxxxxxxx/ >>>>>> >>>>>> As that change fixes something in 6.4, why not cc: stable on it as well? >>>>> >>>>> Sorry, I thought since per-VMA locks were introduced in 6.4 and this >>>>> patch is fixing 6.4 I didn't need to send it to stable for older >>>>> versions. Did I miss something? >>>> >>>> 6.4.y is a stable kernel tree right now, so yes, it needs to be included >>>> there :) >>> >>> I'm in wait-a-few-days-mode on this. To see if we have a backportable >>> fix rather than disabling the feature in -stable. Andrew, how long will you remain in "wait-a-few-days-mode"? Given what Greg said below and that we already had three reports I know of I'd prefer if we could fix this rather sooner than later in mainline -- especially as Arch Linux and openSUSE Tumbleweed likely have switched to 6.4.y already or will do so soon. >> Ok, I think we have a fix posted at [2] and it's cleanly applies to >> 6.4.y stable branch as well. However fork() performance might slightly >> regress, therefore disabling per-VMA locks by default for now seems to >> be preferable even with this fix (see discussion at >> https://lore.kernel.org/all/54cd9ffb-8f4b-003f-c2d6-3b6b0d2cb7d9@xxxxxxxxxx/). >> IOW, both [1] and [2] should be applied to 6.4.y stable. Both apply >> cleanly and I CC'ed stable on [2]. Greg, should I send [1] separately >> to stable@vger? > > We can't do anything for stable until it lands in Linus's tree, so if > you didn't happen to have the stable@ tag in the patch, just email us > the git SHA1 and I can pick it up that way. > > thanks, > > greg k-h Ciao, Thorsten
