On Thu, 19 Nov 2020 at 12:36, Guilherme G. Piccoli <gpiccoli@xxxxxxxxxxxxx> wrote: > > > > On 19/11/2020 05:36, Vincent Guittot wrote: > > On Thu, 19 Nov 2020 at 01:36, Tao Zhou <t1zhou@xxxxxxx> wrote: > >> > >> On Thu, Nov 19, 2020 at 07:50:15AM +0800, Tao Zhou wrote: > >>> On Wed, Nov 18, 2020 at 07:56:38PM -0300, Guilherme G. Piccoli wrote: > >>>> Hi Vincent (and all CCed), I'm sorry to ping about such "old" patch, but > >>>> we experienced a similar condition to what this patch addresses; it's an > >>>> older kernel (4.15.x) but when suggesting the users to move to an > >>>> updated 5.4.x kernel, we noticed that this patch is not there, although > >>>> similar ones are (like [0] and [1]). > >>>> > >>>> So, I'd like to ask if there's any particular reason to not backport > >>>> this fix to stable kernels, specially the longterm 5.4. The main reason > >>>> behind the question is that the code is very complex for non-experienced > >>>> scheduler developers, and I'm afraid in suggesting such backport to 5.4 > >>>> and introduce complex-to-debug issues. > >>>> > >>>> Let me know your thoughts Vincent (and all CCed), thanks in advance. > >>>> Cheers, > >>>> > >>>> > >>>> Guilherme > >>>> > >>>> > >>>> P.S. For those that deleted this thread from the email client, here's a > >>>> link: > >>>> https://lore.kernel.org/lkml/20200513135528.4742-1-vincent.guittot@xxxxxxxxxx/ > >>>> > >>>> > >>>> [0] > >>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fe61468b2cb > >>>> > >>>> [1] > >>>> https://lore.kernel.org/lkml/20200506141821.GA9773@xxxxxxxxxxxxxxxxxxxxxxxxx/ > >>>> <- great thread BTW! > >>> > >>> 'sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to > >>> 5.4-stable tree' > >>> > >>> You could check above. But I do not have the link about this. Can't search it > >>> on LKML web: https://lore.kernel.org/lkml/ > >>> > >>> BTW: 'ouwen210@xxxxxxxxxxx' and 'zohooouoto@xxxxxxxxxxx' all is myself. > >>> > >>> Sorry for the confusing.. > >>> > >>> Thanks. > >> > >> Sorry again. I forget something. It is in the stable. > >> > >> Here it is: > >> > >> https://lore.kernel.org/stable/159041776924279@xxxxxxxxx/ > > > > I think it has never been applied to stable. > > As you mentioned, the backport has been sent : > > https://lore.kernel.org/stable/20200525172709.GB7427@vingu-book/ > > > > I received another emailed in September and pointed out to the > > backport : https://www.spinics.net/lists/stable/msg410445.html > > > > > >> > > Thanks a lot Tao and Vincent! Nice to know that you already worked the > backport, gives much more confidence when the author does that heheh > > So, this should go to stable 5.4.y, but not 4.19.y IIUC? Yeah. they should be backported up to v5.1 but not earlier Regards, Vincent > Cheers, > > > Guilherme
