Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Guilherme G. Piccoli]

Hi Sasha / Peter, is there anything blocking this backport from Vincent
to get merged in 5.4.y?

Thanks in advance,


Guilherme

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Guilherme Piccoli]

On Thu, Nov 19, 2020 at 11:56 AM Guilherme G. Piccoli
<gpiccoli@canonical.com> wrote:
>
> Hi Sasha / Peter, is there anything blocking this backport from Vincent
> to get merged in 5.4.y?
>
> Thanks in advance,
>
>
> Guilherme

Forgot to mention the original thread link:
https://lore.kernel.org/stable/20200525172709.GB7427@vingu-book/#t

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Guilherme Piccoli]

On Thu, Nov 19, 2020 at 1:44 PM Tao Zhou <ouwen210@hotmail.com> wrote:
> [...]
> That time I realized something, but..
> I try to remember something and get some impression.
>
> We need to update the below when do not need to enqueue entity because
> this is added for runnable_avg updating,
>
>         update_load_avg(cfs_rq, se, UPDATE_TG);
>         se_update_runnable(se);
>
> Earlier version do not introduce the above to only update runnable_avg.
> Use one *for loop* is enough though. Please correct me if I am wrong.
>

Thanks a lot Tao! I'm not sure, I'm definitely not an expert in the
scheduler. Will defer this one to Vincent / Peter / Phil / Ben.
Cheers!

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Sasha Levin]

On Thu, Nov 19, 2020 at 11:56:01AM -0300, Guilherme G. Piccoli wrote:
>Hi Sasha / Peter, is there anything blocking this backport from Vincent
>to get merged in 5.4.y?

An ack from Peter...

-- 
Thanks,
Sasha

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Nivedita Singhvi]

On 11/20/20 12:27 AM, Sasha Levin wrote:
> On Thu, Nov 19, 2020 at 11:56:01AM -0300, Guilherme G. Piccoli wrote:
>> Hi Sasha / Peter, is there anything blocking this backport from Vincent
>> to get merged in 5.4.y?
>
> An ack from Peter...
>

Hey Peter,

Any concerns with this patch getting merged?  We are seeing
it in production, looks like, so would be good to get it into stable.


Nivedita

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Guilherme G. Piccoli]

Hey Sasha, sorry to annoy again, but maybe Peter is very busy - wouldn't
be possible maybe to get that merged after a review from Ben or Ingo? I
see them in the MAINTAINERS file, specially Ben as CONFIG_CFS_BANDWIDTH
maintainer.

I understand the confidence in this patch is relatively high, since it's
a backport from the author, right?

Let me know your thoughts, and thanks all in advance!
Cheers,


Guilherme

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Greg KH]

On Tue, Dec 01, 2020 at 12:03:18PM -0300, Guilherme G. Piccoli wrote:
> Hey Sasha, sorry to annoy again, but maybe Peter is very busy - wouldn't
> be possible maybe to get that merged after a review from Ben or Ingo? I
> see them in the MAINTAINERS file, specially Ben as CONFIG_CFS_BANDWIDTH
> maintainer.
> 
> I understand the confidence in this patch is relatively high, since it's
> a backport from the author, right?

I still want to see an ack from the maintainer please.

thanks,

greg k-h

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Vincent Guittot]

On Wed, 2 Dec 2020 at 08:49, Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Tue, Dec 01, 2020 at 12:03:18PM -0300, Guilherme G. Piccoli wrote:
> > Hey Sasha, sorry to annoy again, but maybe Peter is very busy - wouldn't
> > be possible maybe to get that merged after a review from Ben or Ingo? I
> > see them in the MAINTAINERS file, specially Ben as CONFIG_CFS_BANDWIDTH
> > maintainer.
> >
> > I understand the confidence in this patch is relatively high, since it's
> > a backport from the author, right?
>
> I still want to see an ack from the maintainer please.

SCHEDULER
M: Ingo Molnar <mingo@redhat.com>
M: Peter Zijlstra <peterz@infradead.org>
M: Juri Lelli <juri.lelli@redhat.com> (SCHED_DEADLINE)
M: Vincent Guittot <vincent.guittot@linaro.org> (SCHED_NORMAL)
R: Dietmar Eggemann <dietmar.eggemann@arm.com> (SCHED_NORMAL)
R: Steven Rostedt <rostedt@goodmis.org> (SCHED_FIFO/SCHED_RR)
R: Ben Segall <bsegall@google.com> (CONFIG_CFS_BANDWIDTH)
R: Mel Gorman <mgorman@suse.de> (CONFIG_NUMA_BALANCING)
L: linux-kernel@vger.kernel.org
T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched/core
S: Maintained
F: kernel/sched/
F: include/linux/sched.h
F: include/uapi/linux/sched.h
F: include/linux/wait.h
F: include/linux/preempt.h

Isn't me and Ben enough in this case ?

>
> thanks,
>
> greg k-h

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Peter Zijlstra]

On Wed, Dec 02, 2020 at 09:21:19AM +0100, Vincent Guittot wrote:
> On Wed, 2 Dec 2020 at 08:49, Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> > On Tue, Dec 01, 2020 at 12:03:18PM -0300, Guilherme G. Piccoli wrote:
> > > Hey Sasha, sorry to annoy again, but maybe Peter is very busy - wouldn't
> > > be possible maybe to get that merged after a review from Ben or Ingo? I
> > > see them in the MAINTAINERS file, specially Ben as CONFIG_CFS_BANDWIDTH
> > > maintainer.
> > >
> > > I understand the confidence in this patch is relatively high, since it's
> > > a backport from the author, right?
> >
> > I still want to see an ack from the maintainer please.
> 
> SCHEDULER

> M: Vincent Guittot <vincent.guittot@linaro.org> (SCHED_NORMAL)

Vincent is also the one that knows that leaf code best, he did the
backport, you're not going to get better than that.

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Sasha Levin]

On Wed, Dec 02, 2020 at 10:44:28AM +0100, Peter Zijlstra wrote:
>On Wed, Dec 02, 2020 at 09:21:19AM +0100, Vincent Guittot wrote:
>> On Wed, 2 Dec 2020 at 08:49, Greg KH <gregkh@linuxfoundation.org> wrote:
>> >
>> > On Tue, Dec 01, 2020 at 12:03:18PM -0300, Guilherme G. Piccoli wrote:
>> > > Hey Sasha, sorry to annoy again, but maybe Peter is very busy - wouldn't
>> > > be possible maybe to get that merged after a review from Ben or Ingo? I
>> > > see them in the MAINTAINERS file, specially Ben as CONFIG_CFS_BANDWIDTH
>> > > maintainer.
>> > >
>> > > I understand the confidence in this patch is relatively high, since it's
>> > > a backport from the author, right?
>> >
>> > I still want to see an ack from the maintainer please.
>>
>> SCHEDULER
>
>> M: Vincent Guittot <vincent.guittot@linaro.org> (SCHED_NORMAL)
>
>Vincent is also the one that knows that leaf code best, he did the
>backport, you're not going to get better than that.

So I've asked for someone else to review this because the backport is
somehat different from the upstream commit. Ideally we want these types
of backports to be peer reviewed, just like any other commit that lands
upstream.

If the sched folks feel good about that backport (as indicated above...)
I'll happily merge it in.

-- 
Thanks,
Sasha

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Greg KH]

On Thu, Nov 19, 2020 at 11:56:01AM -0300, Guilherme G. Piccoli wrote:
> Hi Sasha / Peter, is there anything blocking this backport from Vincent
> to get merged in 5.4.y?

The backport doesn't apply to the tree.  How did you test this?

thanks,

greg k-h

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Nivedita Singhvi]

On 12/6/20 3:27 PM, Greg KH wrote:
> On Thu, Nov 19, 2020 at 11:56:01AM -0300, Guilherme G. Piccoli wrote:
>> Hi Sasha / Peter, is there anything blocking this backport from Vincent
>> to get merged in 5.4.y?
> 
> The backport doesn't apply to the tree.  How did you test this?
> 
> thanks,
> 
> greg k-h
> 

Thanks, Greg, Vincent, for sorting this out and committing
to stable upstream..

sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list
commit	294de8933adbdda78acaa3935971d26bb6de745e

I don't have a reproducer but we'll be testing this
to the extent we can beat up on it...


Nivedita

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Sasha Levin]

On Sun, Dec 06, 2020 at 01:07:09PM +0100, Greg KH wrote:
>On Sun, Dec 06, 2020 at 12:54:57PM +0100, Vincent Guittot wrote:
>> On Sun, 6 Dec 2020 at 12:47, Greg KH <gregkh@linuxfoundation.org> wrote:
>> >
>> > On Sun, Dec 06, 2020 at 12:25:12PM +0100, Vincent Guittot wrote:
>> > > On Sun, 6 Dec 2020 at 10:56, Greg KH <gregkh@linuxfoundation.org> wrote:
>> > > >
>> > > > On Mon, May 25, 2020 at 07:27:09PM +0200, Vincent Guittot wrote:
>> > > > > Le lundi 25 mai 2020 à 16:42:49 (+0200), gregkh@linuxfoundation.org a écrit :
>> > > > > >
>> > > > > > The patch below does not apply to the 5.4-stable tree.
>> > > > > > If someone wants it applied there, or to any other stable or longterm
>> > > > > > tree, then please email the backport, including the original git commit
>> > > > > > id to <stable@vger.kernel.org>.
>> > > > >
>> > > > > This patch needs  commit
>> > > > >     b34cb07dde7c ("sched/fair: Fix enqueue_task_fair() warning some more")
>> > > > > to be applied first. But then, it will not apply. The backport is :
>> > > > >
>> > > > > [ Upstream commit 39f23ce07b9355d05a64ae303ce20d1c4b92b957 upstream ]
>> > > > >
>> > > > > Although not exactly identical, unthrottle_cfs_rq() and enqueue_task_fair()
>> > > > > are quite close and follow the same sequence for enqueuing an entity in the
>> > > > > cfs hierarchy. Modify unthrottle_cfs_rq() to use the same pattern as
>> > > > > enqueue_task_fair(). This fixes a problem already faced with the latter and
>> > > > > add an optimization in the last for_each_sched_entity loop.
>> > > > >
>> > > > > Fixes: fe61468b2cb (sched/fair: Fix enqueue_task_fair warning)
>> > > > > Reported-by Tao Zhou <zohooouoto@zoho.com.cn>
>> > > > > Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
>> > > > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
>> > > > > Reviewed-by: Phil Auld <pauld@redhat.com>
>> > > > > Reviewed-by: Ben Segall <bsegall@google.com>
>> > > > > Link: https://lkml.kernel.org/r/20200513135528.4742-1-vincent.guittot@linaro.org
>> > > > > ---
>> > > > >  kernel/sched/fair.c | 36 ++++++++++++++++++++++++++++--------
>> > > > >  1 file changed, 28 insertions(+), 8 deletions(-)
>> > > >
>> > > > This patch doesn't apply to the 5.4.y tree at all.  Can someone please
>> > > > provide a working backport?
>> > >
>> > > It seems that commit b34cb07dde7c ("sched/fair: Fix
>> > > enqueue_task_fair() warning some more") has already been applied back
>> > > in May. But then, I'm able to apply this patch on top of
>> > > v5.4.y/v5.4.81
>> > >
>> >
>> > What is "this patch" here?  I tried to apply 39f23ce07b93 ("sched/fair:
>> > Fix unthrottle_cfs_rq() for leaf_cfs_rq list") directly to the 5.4 tree
>> > and it too did not apply.
>>
>> commit 39f23ce07b93 ("sched/fair: Fix unthrottle_cfs_rq() for
>> leaf_cfs_rq list") can't apply because there are several changes which
>> are not fixes which have been applied since v5.4 on the same code.
>>
>> This patch is the backport on v5.4 of the commit 39f23ce07b93
>
>What is "this"?  I tried to apply the above patch to the 5.4.y tree, and
>it didn't apply.  So I still do not understand what I can do here...

It's already in our 5.4 tree I've added it there a few days ago :)

-- 
Thanks,
Sasha

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Vincent Guittot]

On Sun, 6 Dec 2020 at 13:05, Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Sun, Dec 06, 2020 at 12:54:57PM +0100, Vincent Guittot wrote:
> > On Sun, 6 Dec 2020 at 12:47, Greg KH <gregkh@linuxfoundation.org> wrote:
> > >
> > > On Sun, Dec 06, 2020 at 12:25:12PM +0100, Vincent Guittot wrote:
> > > > On Sun, 6 Dec 2020 at 10:56, Greg KH <gregkh@linuxfoundation.org> wrote:
> > > > >
> > > > > On Mon, May 25, 2020 at 07:27:09PM +0200, Vincent Guittot wrote:
> > > > > > Le lundi 25 mai 2020 à 16:42:49 (+0200), gregkh@linuxfoundation.org a écrit :
> > > > > > >
> > > > > > > The patch below does not apply to the 5.4-stable tree.
> > > > > > > If someone wants it applied there, or to any other stable or longterm
> > > > > > > tree, then please email the backport, including the original git commit
> > > > > > > id to <stable@vger.kernel.org>.
> > > > > >
> > > > > > This patch needs  commit
> > > > > >     b34cb07dde7c ("sched/fair: Fix enqueue_task_fair() warning some more")
> > > > > > to be applied first. But then, it will not apply. The backport is :
> > > > > >
> > > > > > [ Upstream commit 39f23ce07b9355d05a64ae303ce20d1c4b92b957 upstream ]
> > > > > >
> > > > > > Although not exactly identical, unthrottle_cfs_rq() and enqueue_task_fair()
> > > > > > are quite close and follow the same sequence for enqueuing an entity in the
> > > > > > cfs hierarchy. Modify unthrottle_cfs_rq() to use the same pattern as
> > > > > > enqueue_task_fair(). This fixes a problem already faced with the latter and
> > > > > > add an optimization in the last for_each_sched_entity loop.
> > > > > >
> > > > > > Fixes: fe61468b2cb (sched/fair: Fix enqueue_task_fair warning)
> > > > > > Reported-by Tao Zhou <zohooouoto@zoho.com.cn>
> > > > > > Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> > > > > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> > > > > > Reviewed-by: Phil Auld <pauld@redhat.com>
> > > > > > Reviewed-by: Ben Segall <bsegall@google.com>
> > > > > > Link: https://lkml.kernel.org/r/20200513135528.4742-1-vincent.guittot@linaro.org
> > > > > > ---
> > > > > >  kernel/sched/fair.c | 36 ++++++++++++++++++++++++++++--------
> > > > > >  1 file changed, 28 insertions(+), 8 deletions(-)
> > > > >
> > > > > This patch doesn't apply to the 5.4.y tree at all.  Can someone please
> > > > > provide a working backport?
> > > >
> > > > It seems that commit b34cb07dde7c ("sched/fair: Fix
> > > > enqueue_task_fair() warning some more") has already been applied back
> > > > in May. But then, I'm able to apply this patch on top of
> > > > v5.4.y/v5.4.81
> > > >
> > >
> > > What is "this patch" here?  I tried to apply 39f23ce07b93 ("sched/fair:
> > > Fix unthrottle_cfs_rq() for leaf_cfs_rq list") directly to the 5.4 tree
> > > and it too did not apply.
> >
> > commit 39f23ce07b93 ("sched/fair: Fix unthrottle_cfs_rq() for
> > leaf_cfs_rq list") can't apply because there are several changes which
> > are not fixes which have been applied since v5.4 on the same code.
> >
> > This patch is the backport on v5.4 of the commit 39f23ce07b93
>
> What is "this"?  I tried to apply the above patch to the 5.4.y tree, and

I was referring to the email  <20200525172709.GB7427@vingu-book>

> it didn't apply.  So I still do not understand what I can do here...

Let me resend it with a clean subject title

>
> greg k-h

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Greg KH]

On Sun, Dec 06, 2020 at 12:54:57PM +0100, Vincent Guittot wrote:
> On Sun, 6 Dec 2020 at 12:47, Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> > On Sun, Dec 06, 2020 at 12:25:12PM +0100, Vincent Guittot wrote:
> > > On Sun, 6 Dec 2020 at 10:56, Greg KH <gregkh@linuxfoundation.org> wrote:
> > > >
> > > > On Mon, May 25, 2020 at 07:27:09PM +0200, Vincent Guittot wrote:
> > > > > Le lundi 25 mai 2020 à 16:42:49 (+0200), gregkh@linuxfoundation.org a écrit :
> > > > > >
> > > > > > The patch below does not apply to the 5.4-stable tree.
> > > > > > If someone wants it applied there, or to any other stable or longterm
> > > > > > tree, then please email the backport, including the original git commit
> > > > > > id to <stable@vger.kernel.org>.
> > > > >
> > > > > This patch needs  commit
> > > > >     b34cb07dde7c ("sched/fair: Fix enqueue_task_fair() warning some more")
> > > > > to be applied first. But then, it will not apply. The backport is :
> > > > >
> > > > > [ Upstream commit 39f23ce07b9355d05a64ae303ce20d1c4b92b957 upstream ]
> > > > >
> > > > > Although not exactly identical, unthrottle_cfs_rq() and enqueue_task_fair()
> > > > > are quite close and follow the same sequence for enqueuing an entity in the
> > > > > cfs hierarchy. Modify unthrottle_cfs_rq() to use the same pattern as
> > > > > enqueue_task_fair(). This fixes a problem already faced with the latter and
> > > > > add an optimization in the last for_each_sched_entity loop.
> > > > >
> > > > > Fixes: fe61468b2cb (sched/fair: Fix enqueue_task_fair warning)
> > > > > Reported-by Tao Zhou <zohooouoto@zoho.com.cn>
> > > > > Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> > > > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> > > > > Reviewed-by: Phil Auld <pauld@redhat.com>
> > > > > Reviewed-by: Ben Segall <bsegall@google.com>
> > > > > Link: https://lkml.kernel.org/r/20200513135528.4742-1-vincent.guittot@linaro.org
> > > > > ---
> > > > >  kernel/sched/fair.c | 36 ++++++++++++++++++++++++++++--------
> > > > >  1 file changed, 28 insertions(+), 8 deletions(-)
> > > >
> > > > This patch doesn't apply to the 5.4.y tree at all.  Can someone please
> > > > provide a working backport?
> > >
> > > It seems that commit b34cb07dde7c ("sched/fair: Fix
> > > enqueue_task_fair() warning some more") has already been applied back
> > > in May. But then, I'm able to apply this patch on top of
> > > v5.4.y/v5.4.81
> > >
> >
> > What is "this patch" here?  I tried to apply 39f23ce07b93 ("sched/fair:
> > Fix unthrottle_cfs_rq() for leaf_cfs_rq list") directly to the 5.4 tree
> > and it too did not apply.
> 
> commit 39f23ce07b93 ("sched/fair: Fix unthrottle_cfs_rq() for
> leaf_cfs_rq list") can't apply because there are several changes which
> are not fixes which have been applied since v5.4 on the same code.
> 
> This patch is the backport on v5.4 of the commit 39f23ce07b93

What is "this"?  I tried to apply the above patch to the 5.4.y tree, and
it didn't apply.  So I still do not understand what I can do here...

greg k-h

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Vincent Guittot]

On Sun, 6 Dec 2020 at 12:47, Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Sun, Dec 06, 2020 at 12:25:12PM +0100, Vincent Guittot wrote:
> > On Sun, 6 Dec 2020 at 10:56, Greg KH <gregkh@linuxfoundation.org> wrote:
> > >
> > > On Mon, May 25, 2020 at 07:27:09PM +0200, Vincent Guittot wrote:
> > > > Le lundi 25 mai 2020 à 16:42:49 (+0200), gregkh@linuxfoundation.org a écrit :
> > > > >
> > > > > The patch below does not apply to the 5.4-stable tree.
> > > > > If someone wants it applied there, or to any other stable or longterm
> > > > > tree, then please email the backport, including the original git commit
> > > > > id to <stable@vger.kernel.org>.
> > > >
> > > > This patch needs  commit
> > > >     b34cb07dde7c ("sched/fair: Fix enqueue_task_fair() warning some more")
> > > > to be applied first. But then, it will not apply. The backport is :
> > > >
> > > > [ Upstream commit 39f23ce07b9355d05a64ae303ce20d1c4b92b957 upstream ]
> > > >
> > > > Although not exactly identical, unthrottle_cfs_rq() and enqueue_task_fair()
> > > > are quite close and follow the same sequence for enqueuing an entity in the
> > > > cfs hierarchy. Modify unthrottle_cfs_rq() to use the same pattern as
> > > > enqueue_task_fair(). This fixes a problem already faced with the latter and
> > > > add an optimization in the last for_each_sched_entity loop.
> > > >
> > > > Fixes: fe61468b2cb (sched/fair: Fix enqueue_task_fair warning)
> > > > Reported-by Tao Zhou <zohooouoto@zoho.com.cn>
> > > > Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> > > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> > > > Reviewed-by: Phil Auld <pauld@redhat.com>
> > > > Reviewed-by: Ben Segall <bsegall@google.com>
> > > > Link: https://lkml.kernel.org/r/20200513135528.4742-1-vincent.guittot@linaro.org
> > > > ---
> > > >  kernel/sched/fair.c | 36 ++++++++++++++++++++++++++++--------
> > > >  1 file changed, 28 insertions(+), 8 deletions(-)
> > >
> > > This patch doesn't apply to the 5.4.y tree at all.  Can someone please
> > > provide a working backport?
> >
> > It seems that commit b34cb07dde7c ("sched/fair: Fix
> > enqueue_task_fair() warning some more") has already been applied back
> > in May. But then, I'm able to apply this patch on top of
> > v5.4.y/v5.4.81
> >
>
> What is "this patch" here?  I tried to apply 39f23ce07b93 ("sched/fair:
> Fix unthrottle_cfs_rq() for leaf_cfs_rq list") directly to the 5.4 tree
> and it too did not apply.

commit 39f23ce07b93 ("sched/fair: Fix unthrottle_cfs_rq() for
leaf_cfs_rq list") can't apply because there are several changes which
are not fixes which have been applied since v5.4 on the same code.

This patch is the backport on v5.4 of the commit 39f23ce07b93

>
> confused,
>
> greg k-h

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Greg KH]

On Sun, Dec 06, 2020 at 12:25:12PM +0100, Vincent Guittot wrote:
> On Sun, 6 Dec 2020 at 10:56, Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> > On Mon, May 25, 2020 at 07:27:09PM +0200, Vincent Guittot wrote:
> > > Le lundi 25 mai 2020 à 16:42:49 (+0200), gregkh@linuxfoundation.org a écrit :
> > > >
> > > > The patch below does not apply to the 5.4-stable tree.
> > > > If someone wants it applied there, or to any other stable or longterm
> > > > tree, then please email the backport, including the original git commit
> > > > id to <stable@vger.kernel.org>.
> > >
> > > This patch needs  commit
> > >     b34cb07dde7c ("sched/fair: Fix enqueue_task_fair() warning some more")
> > > to be applied first. But then, it will not apply. The backport is :
> > >
> > > [ Upstream commit 39f23ce07b9355d05a64ae303ce20d1c4b92b957 upstream ]
> > >
> > > Although not exactly identical, unthrottle_cfs_rq() and enqueue_task_fair()
> > > are quite close and follow the same sequence for enqueuing an entity in the
> > > cfs hierarchy. Modify unthrottle_cfs_rq() to use the same pattern as
> > > enqueue_task_fair(). This fixes a problem already faced with the latter and
> > > add an optimization in the last for_each_sched_entity loop.
> > >
> > > Fixes: fe61468b2cb (sched/fair: Fix enqueue_task_fair warning)
> > > Reported-by Tao Zhou <zohooouoto@zoho.com.cn>
> > > Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> > > Reviewed-by: Phil Auld <pauld@redhat.com>
> > > Reviewed-by: Ben Segall <bsegall@google.com>
> > > Link: https://lkml.kernel.org/r/20200513135528.4742-1-vincent.guittot@linaro.org
> > > ---
> > >  kernel/sched/fair.c | 36 ++++++++++++++++++++++++++++--------
> > >  1 file changed, 28 insertions(+), 8 deletions(-)
> >
> > This patch doesn't apply to the 5.4.y tree at all.  Can someone please
> > provide a working backport?
> 
> It seems that commit b34cb07dde7c ("sched/fair: Fix
> enqueue_task_fair() warning some more") has already been applied back
> in May. But then, I'm able to apply this patch on top of
> v5.4.y/v5.4.81
> 

What is "this patch" here?  I tried to apply 39f23ce07b93 ("sched/fair:
Fix unthrottle_cfs_rq() for leaf_cfs_rq list") directly to the 5.4 tree
and it too did not apply.

confused,

greg k-h

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Vincent Guittot]

On Sun, 6 Dec 2020 at 10:56, Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Mon, May 25, 2020 at 07:27:09PM +0200, Vincent Guittot wrote:
> > Le lundi 25 mai 2020 à 16:42:49 (+0200), gregkh@linuxfoundation.org a écrit :
> > >
> > > The patch below does not apply to the 5.4-stable tree.
> > > If someone wants it applied there, or to any other stable or longterm
> > > tree, then please email the backport, including the original git commit
> > > id to <stable@vger.kernel.org>.
> >
> > This patch needs  commit
> >     b34cb07dde7c ("sched/fair: Fix enqueue_task_fair() warning some more")
> > to be applied first. But then, it will not apply. The backport is :
> >
> > [ Upstream commit 39f23ce07b9355d05a64ae303ce20d1c4b92b957 upstream ]
> >
> > Although not exactly identical, unthrottle_cfs_rq() and enqueue_task_fair()
> > are quite close and follow the same sequence for enqueuing an entity in the
> > cfs hierarchy. Modify unthrottle_cfs_rq() to use the same pattern as
> > enqueue_task_fair(). This fixes a problem already faced with the latter and
> > add an optimization in the last for_each_sched_entity loop.
> >
> > Fixes: fe61468b2cb (sched/fair: Fix enqueue_task_fair warning)
> > Reported-by Tao Zhou <zohooouoto@zoho.com.cn>
> > Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> > Reviewed-by: Phil Auld <pauld@redhat.com>
> > Reviewed-by: Ben Segall <bsegall@google.com>
> > Link: https://lkml.kernel.org/r/20200513135528.4742-1-vincent.guittot@linaro.org
> > ---
> >  kernel/sched/fair.c | 36 ++++++++++++++++++++++++++++--------
> >  1 file changed, 28 insertions(+), 8 deletions(-)
>
> This patch doesn't apply to the 5.4.y tree at all.  Can someone please
> provide a working backport?

It seems that commit b34cb07dde7c ("sched/fair: Fix
enqueue_task_fair() warning some more") has already been applied back
in May. But then, I'm able to apply this patch on top of
v5.4.y/v5.4.81

Thanks

>
> thanks,
>
> greg k-h

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Greg KH]

On Mon, May 25, 2020 at 07:27:09PM +0200, Vincent Guittot wrote:
> Le lundi 25 mai 2020 à 16:42:49 (+0200), gregkh@linuxfoundation.org a écrit :
> > 
> > The patch below does not apply to the 5.4-stable tree.
> > If someone wants it applied there, or to any other stable or longterm
> > tree, then please email the backport, including the original git commit
> > id to <stable@vger.kernel.org>.
> 
> This patch needs  commit
>     b34cb07dde7c ("sched/fair: Fix enqueue_task_fair() warning some more")
> to be applied first. But then, it will not apply. The backport is :
> 
> [ Upstream commit 39f23ce07b9355d05a64ae303ce20d1c4b92b957 upstream ]
> 
> Although not exactly identical, unthrottle_cfs_rq() and enqueue_task_fair()
> are quite close and follow the same sequence for enqueuing an entity in the
> cfs hierarchy. Modify unthrottle_cfs_rq() to use the same pattern as
> enqueue_task_fair(). This fixes a problem already faced with the latter and
> add an optimization in the last for_each_sched_entity loop.
> 
> Fixes: fe61468b2cb (sched/fair: Fix enqueue_task_fair warning)
> Reported-by Tao Zhou <zohooouoto@zoho.com.cn>
> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Reviewed-by: Phil Auld <pauld@redhat.com>
> Reviewed-by: Ben Segall <bsegall@google.com>
> Link: https://lkml.kernel.org/r/20200513135528.4742-1-vincent.guittot@linaro.org
> ---
>  kernel/sched/fair.c | 36 ++++++++++++++++++++++++++++--------
>  1 file changed, 28 insertions(+), 8 deletions(-)

This patch doesn't apply to the 5.4.y tree at all.  Can someone please
provide a working backport?

thanks,

greg k-h

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Sasha Levin]

On Mon, May 25, 2020 at 07:27:09PM +0200, Vincent Guittot wrote:
>Le lundi 25 mai 2020 à 16:42:49 (+0200), gregkh@linuxfoundation.org a écrit :
>>
>> The patch below does not apply to the 5.4-stable tree.
>> If someone wants it applied there, or to any other stable or longterm
>> tree, then please email the backport, including the original git commit
>> id to <stable@vger.kernel.org>.
>
>This patch needs  commit
>    b34cb07dde7c ("sched/fair: Fix enqueue_task_fair() warning some more")
>to be applied first. But then, it will not apply. The backport is :
>
>[ Upstream commit 39f23ce07b9355d05a64ae303ce20d1c4b92b957 upstream ]
>
>Although not exactly identical, unthrottle_cfs_rq() and enqueue_task_fair()
>are quite close and follow the same sequence for enqueuing an entity in the
>cfs hierarchy. Modify unthrottle_cfs_rq() to use the same pattern as
>enqueue_task_fair(). This fixes a problem already faced with the latter and
>add an optimization in the last for_each_sched_entity loop.
>
>Fixes: fe61468b2cb (sched/fair: Fix enqueue_task_fair warning)
>Reported-by Tao Zhou <zohooouoto@zoho.com.cn>
>Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
>Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
>Reviewed-by: Phil Auld <pauld@redhat.com>
>Reviewed-by: Ben Segall <bsegall@google.com>
>Link: https://lkml.kernel.org/r/20200513135528.4742-1-vincent.guittot@linaro.org

Peter, could you review/ack the backport please? It's very different
from the upstream version.

-- 
Thanks,
Sasha

Re: FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[Vincent Guittot]

Le lundi 25 mai 2020 à 16:42:49 (+0200), gregkh@linuxfoundation.org a écrit :
> 
> The patch below does not apply to the 5.4-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.

This patch needs  commit
    b34cb07dde7c ("sched/fair: Fix enqueue_task_fair() warning some more")
to be applied first. But then, it will not apply. The backport is :

[ Upstream commit 39f23ce07b9355d05a64ae303ce20d1c4b92b957 upstream ]

Although not exactly identical, unthrottle_cfs_rq() and enqueue_task_fair()
are quite close and follow the same sequence for enqueuing an entity in the
cfs hierarchy. Modify unthrottle_cfs_rq() to use the same pattern as
enqueue_task_fair(). This fixes a problem already faced with the latter and
add an optimization in the last for_each_sched_entity loop.

Fixes: fe61468b2cb (sched/fair: Fix enqueue_task_fair warning)
Reported-by Tao Zhou <zohooouoto@zoho.com.cn>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Phil Auld <pauld@redhat.com>
Reviewed-by: Ben Segall <bsegall@google.com>
Link: https://lkml.kernel.org/r/20200513135528.4742-1-vincent.guittot@linaro.org
---
 kernel/sched/fair.c | 36 ++++++++++++++++++++++++++++--------
 1 file changed, 28 insertions(+), 8 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 193b6ab74d7f..36e3bb990845 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4560,7 +4560,6 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
 	struct rq *rq = rq_of(cfs_rq);
 	struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
 	struct sched_entity *se;
-	int enqueue = 1;
 	long task_delta, idle_task_delta;

 	se = cfs_rq->tg->se[cpu_of(rq)];
@@ -4584,21 +4583,41 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
 	idle_task_delta = cfs_rq->idle_h_nr_running;
 	for_each_sched_entity(se) {
 		if (se->on_rq)
-			enqueue = 0;
+			break;
+		cfs_rq = cfs_rq_of(se);
+		enqueue_entity(cfs_rq, se, ENQUEUE_WAKEUP);
+
+		cfs_rq->h_nr_running += task_delta;
+		cfs_rq->idle_h_nr_running += idle_task_delta;

+		/* end evaluation on encountering a throttled cfs_rq */
+		if (cfs_rq_throttled(cfs_rq))
+			goto unthrottle_throttle;
+	}
+
+	for_each_sched_entity(se) {
 		cfs_rq = cfs_rq_of(se);
-		if (enqueue)
-			enqueue_entity(cfs_rq, se, ENQUEUE_WAKEUP);
+
 		cfs_rq->h_nr_running += task_delta;
 		cfs_rq->idle_h_nr_running += idle_task_delta;

+
+		/* end evaluation on encountering a throttled cfs_rq */
 		if (cfs_rq_throttled(cfs_rq))
-			break;
+			goto unthrottle_throttle;
+
+		/*
+		 * One parent has been throttled and cfs_rq removed from the
+		 * list. Add it back to not break the leaf list.
+		 */
+		if (throttled_hierarchy(cfs_rq))
+			list_add_leaf_cfs_rq(cfs_rq);
 	}

-	if (!se)
-		add_nr_running(rq, task_delta);
+	/* At this point se is NULL and we are at root level*/
+	add_nr_running(rq, task_delta);

+unthrottle_throttle:
 	/*
 	 * The cfs_rq_throttled() breaks in the above iteration can result in
 	 * incomplete leaf list maintenance, resulting in triggering the
@@ -4607,7 +4626,8 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
 	for_each_sched_entity(se) {
 		cfs_rq = cfs_rq_of(se);

-		list_add_leaf_cfs_rq(cfs_rq);
+		if (list_add_leaf_cfs_rq(cfs_rq))
+			break;
 	}

 	assert_list_leaf_cfs_rq(rq);
--
2.17.1
 

FAILED: patch "[PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list" failed to apply to 5.4-stable tree

[gregkh]

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 39f23ce07b9355d05a64ae303ce20d1c4b92b957 Mon Sep 17 00:00:00 2001
From: Vincent Guittot <vincent.guittot@linaro.org>
Date: Wed, 13 May 2020 15:55:28 +0200
Subject: [PATCH] sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq list

Although not exactly identical, unthrottle_cfs_rq() and enqueue_task_fair()
are quite close and follow the same sequence for enqueuing an entity in the
cfs hierarchy. Modify unthrottle_cfs_rq() to use the same pattern as
enqueue_task_fair(). This fixes a problem already faced with the latter and
add an optimization in the last for_each_sched_entity loop.

Fixes: fe61468b2cb (sched/fair: Fix enqueue_task_fair warning)
Reported-by Tao Zhou <zohooouoto@zoho.com.cn>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Phil Auld <pauld@redhat.com>
Reviewed-by: Ben Segall <bsegall@google.com>
Link: https://lkml.kernel.org/r/20200513135528.4742-1-vincent.guittot@linaro.org

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c6d57c334d51..538ba5d94e99 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4774,7 +4774,6 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
 	struct rq *rq = rq_of(cfs_rq);
 	struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
 	struct sched_entity *se;
-	int enqueue = 1;
 	long task_delta, idle_task_delta;
 
 	se = cfs_rq->tg->se[cpu_of(rq)];
@@ -4798,26 +4797,44 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
 	idle_task_delta = cfs_rq->idle_h_nr_running;
 	for_each_sched_entity(se) {
 		if (se->on_rq)
-			enqueue = 0;
+			break;
+		cfs_rq = cfs_rq_of(se);
+		enqueue_entity(cfs_rq, se, ENQUEUE_WAKEUP);
 
+		cfs_rq->h_nr_running += task_delta;
+		cfs_rq->idle_h_nr_running += idle_task_delta;
+
+		/* end evaluation on encountering a throttled cfs_rq */
+		if (cfs_rq_throttled(cfs_rq))
+			goto unthrottle_throttle;
+	}
+
+	for_each_sched_entity(se) {
 		cfs_rq = cfs_rq_of(se);
-		if (enqueue) {
-			enqueue_entity(cfs_rq, se, ENQUEUE_WAKEUP);
-		} else {
-			update_load_avg(cfs_rq, se, 0);
-			se_update_runnable(se);
-		}
+
+		update_load_avg(cfs_rq, se, UPDATE_TG);
+		se_update_runnable(se);
 
 		cfs_rq->h_nr_running += task_delta;
 		cfs_rq->idle_h_nr_running += idle_task_delta;
 
+
+		/* end evaluation on encountering a throttled cfs_rq */
 		if (cfs_rq_throttled(cfs_rq))
-			break;
+			goto unthrottle_throttle;
+
+		/*
+		 * One parent has been throttled and cfs_rq removed from the
+		 * list. Add it back to not break the leaf list.
+		 */
+		if (throttled_hierarchy(cfs_rq))
+			list_add_leaf_cfs_rq(cfs_rq);
 	}
 
-	if (!se)
-		add_nr_running(rq, task_delta);
+	/* At this point se is NULL and we are at root level*/
+	add_nr_running(rq, task_delta);
 
+unthrottle_throttle:
 	/*
 	 * The cfs_rq_throttled() breaks in the above iteration can result in
 	 * incomplete leaf list maintenance, resulting in triggering the
@@ -4826,7 +4843,8 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
 	for_each_sched_entity(se) {
 		cfs_rq = cfs_rq_of(se);
 
-		list_add_leaf_cfs_rq(cfs_rq);
+		if (list_add_leaf_cfs_rq(cfs_rq))
+			break;
 	}
 
 	assert_list_leaf_cfs_rq(rq);