Messages in this thread | | | Subject | Re: [PATCH v2 4/5] mm, kswapd: replace kswapd compaction with waking up kcompactd | From | Vlastimil Babka <> | Date | Wed, 2 Mar 2016 15:40:55 +0100 |
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On 03/02/2016 03:22 PM, Joonsoo Kim wrote: > 2016-03-02 23:09 GMT+09:00 Vlastimil Babka <vbabka@suse.cz>: >> On 03/02/2016 02:57 PM, Joonsoo Kim wrote: >>> >>> >>> Yes, I know. >>> What I'd like to say here is that you need to care current_is_kswapd() in >>> this patch. This patch unintentionally change the back ground compaction >>> thread >>> behaviour to restart compaction by every 64 trials because calling >>> curret_is_kswapd() >> >>> by kcompactd would return false and is treated as direct reclaim. >> >> Oh, you mean this path to reset the skip bits. I see. But if skip bits are >> already reset by kswapd when waking kcompactd, then effect of another (rare) >> reset in kcompactd itself will be minimal? > > If you care current_is_kswapd() in this patch properly (properly means change > like "current_is_kcompactd()), reset in kswapd would not > happen because, compact_blockskip_flush would not be set by kcompactd. > > In this case, patch 5 would have it's own meaning so cannot be folded.
So I understand that patch 5 would be just about this?
- if (compaction_restarting(zone, cc->order) && !current_is_kcompactd()) + if (compaction_restarting(zone, cc->order)) __reset_isolation_suitable(zone);
I'm more inclined to fold it in that case.
> Thanks. > >>> Result of patch 4 >>> and patch 5 would be same. >> >> >> It's certainly possible to fold patch 5 into 4. I posted them separately >> mainly to make review more feasible. But the differences in results are >> already quite small. >>
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