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

From: Xiaqing (A)
Date: Wed Dec 02 2020 - 22:14:09 EST




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@xxxxxxxxx>
---
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;
}