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[2/9] mm: vmscan: use nid from shrink_control for tracepoint

Message ID 20201202182725.265020-3-shy828301@gmail.com (mailing list archive)
State New
Headers show
Series Make shrinker's nr_deferred memcg aware | expand

Commit Message

Yang Shi Dec. 2, 2020, 6:27 p.m. UTC
The tracepoint's nid should show what node the shrink happens on, the start tracepoint
uses nid from shrinkctl, but the nid might be set to 0 before end tracepoint if the
shrinker is not NUMA aware, so the traceing log may show the shrink happens on one
node but end up on the other node.  It seems confusing.  And the following patch
will remove using nid directly in do_shrink_slab(), this patch also helps cleanup
the code.

Signed-off-by: Yang Shi <shy828301@gmail.com>
---
 mm/vmscan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Xiaqing (A) Dec. 3, 2020, 3:13 a.m. UTC | #1
On 2020/12/3 2:27, Yang Shi wrote:
> The tracepoint's nid should show what node the shrink happens on, the start tracepoint
> uses nid from shrinkctl, but the nid might be set to 0 before end tracepoint if the
> shrinker is not NUMA aware, so the traceing log may show the shrink happens on one
> node but end up on the other node.  It seems confusing.  And the following patch
> will remove using nid directly in do_shrink_slab(), this patch also helps cleanup
> the code.
>
> Signed-off-by: Yang Shi <shy828301@gmail.com>
> ---
>   mm/vmscan.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 7d6186a07daf..457ce04eebf2 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -533,7 +533,7 @@ static unsigned long do_shrink_slab(struct shrink_control *shrinkctl,
>   	new_nr = atomic_long_add_return(next_deferred,
>   					&shrinker->nr_deferred[nid]);
>   
> -	trace_mm_shrink_slab_end(shrinker, nid, freed, nr, new_nr, total_scan);
> +	trace_mm_shrink_slab_end(shrinker, shrinkctl->nid, freed, nr, new_nr, total_scan);

Hi, Yang

When I read this patch, I wondered why you modified it so much until I read patch6. Could you merge
this patch into patch6?

Thanks!

>   	return freed;
>   }
>
Yang Shi Dec. 11, 2020, 7:20 p.m. UTC | #2
On Wed, Dec 2, 2020 at 7:13 PM Xiaqing (A) <saberlily.xia@hisilicon.com> wrote:
>
>
>
> On 2020/12/3 2:27, Yang Shi wrote:
> > The tracepoint's nid should show what node the shrink happens on, the start tracepoint
> > uses nid from shrinkctl, but the nid might be set to 0 before end tracepoint if the
> > shrinker is not NUMA aware, so the traceing log may show the shrink happens on one
> > node but end up on the other node.  It seems confusing.  And the following patch
> > will remove using nid directly in do_shrink_slab(), this patch also helps cleanup
> > the code.
> >
> > Signed-off-by: Yang Shi <shy828301@gmail.com>
> > ---
> >   mm/vmscan.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/mm/vmscan.c b/mm/vmscan.c
> > index 7d6186a07daf..457ce04eebf2 100644
> > --- a/mm/vmscan.c
> > +++ b/mm/vmscan.c
> > @@ -533,7 +533,7 @@ static unsigned long do_shrink_slab(struct shrink_control *shrinkctl,
> >       new_nr = atomic_long_add_return(next_deferred,
> >                                       &shrinker->nr_deferred[nid]);
> >
> > -     trace_mm_shrink_slab_end(shrinker, nid, freed, nr, new_nr, total_scan);
> > +     trace_mm_shrink_slab_end(shrinker, shrinkctl->nid, freed, nr, new_nr, total_scan);
>
> Hi, Yang
>
> When I read this patch, I wondered why you modified it so much until I read patch6. Could you merge
> this patch into patch6?

Sorry for the late reply. It could be, but I was inclined to think
this is a bug and we might need backport it to stable, so I leave it
as a standalone patch.

>
> Thanks!
>
> >       return freed;
> >   }
> >
>
diff mbox series

Patch

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 7d6186a07daf..457ce04eebf2 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -533,7 +533,7 @@  static unsigned long do_shrink_slab(struct shrink_control *shrinkctl,
 	new_nr = atomic_long_add_return(next_deferred,
 					&shrinker->nr_deferred[nid]);
 
-	trace_mm_shrink_slab_end(shrinker, nid, freed, nr, new_nr, total_scan);
+	trace_mm_shrink_slab_end(shrinker, shrinkctl->nid, freed, nr, new_nr, total_scan);
 	return freed;
 }