[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <7005b574-c9c4-4e74-ad81-ac1a1163c269@vivo.com>
Date: Fri, 20 Oct 2023 12:36:46 +0800
From: zhiguojiang <justinjiang@...o.com>
To: Matthew Wilcox <willy@...radead.org>
Cc: David Hildenbrand <david@...hat.com>,
Andrew Morton <akpm@...ux-foundation.org>, linux-mm@...ck.org,
linux-kernel@...r.kernel.org, opensource.kernel@...o.com
Subject: Re: [PATCH v2 1/2] mm:vmscan: the dirty folio in folio_list skip
unmap
在 2023/10/20 12:15, Matthew Wilcox 写道:
> On Fri, Oct 20, 2023 at 11:59:33AM +0800, zhiguojiang wrote:
>>>> @@ -1261,43 +1305,6 @@ static unsigned int shrink_folio_list(struct
>>>> list_head *folio_list,
>>>> enum ttu_flags flags = TTU_BATCH_FLUSH;
>>>> bool was_swapbacked =
>>>> folio_test_swapbacked(folio);
>>>>
>>>> - if (folio_test_dirty(folio)) {
>>>> - /*
>>>> - * Only kswapd can writeback
>>>> filesystem folios
>>>> - * to avoid risk of stack overflow.
>>>> But avoid
>>>> - * injecting inefficient single-folio
>>>> I/O into
>>>> - * flusher writeback as much as
>>>> possible: only
>>>> - * write folios when we've encountered
>>>> many
>>>> - * dirty folios, and when we've
>>>> already scanned
>>>> - * the rest of the LRU for clean
>>>> folios and see
>>>> - * the same dirty folios again (with
>>>> the reclaim
>>>> - * flag set).
>>>> - */
>>>> - if (folio_is_file_lru(folio) &&
>>>> - (!current_is_kswapd() ||
>>>> - !folio_test_reclaim(folio) ||
>>>> - !test_bit(PGDAT_DIRTY,
>>>> &pgdat->flags))) {
>>>> - /*
>>>> - * Immediately reclaim when
>>>> written back.
>>>> - * Similar in principle to
>>>> folio_deactivate()
>>>> - * except we already have the
>>>> folio isolated
>>>> - * and know it's dirty
>>>> - */
>>>> - node_stat_mod_folio(folio,
>>>> NR_VMSCAN_IMMEDIATE,
>>>> - nr_pages);
>>>> - folio_set_reclaim(folio);
>>>> -
>>>> - goto activate_locked;
>>>> - }
>>>> -
>>>> - if (references == FOLIOREF_RECLAIM_CLEAN)
>>>> - goto keep_locked;
>>>> - if (!may_enter_fs(folio, sc->gfp_mask))
>>>> - goto keep_locked;
>>>> - if (!sc->may_writepage)
>>>> - goto keep_locked;
>>>> - }
>>>> -
>>>> if (folio_test_pmd_mappable(folio))
>>>> flags |= TTU_SPLIT_HUGE_PMD;
>>>>
>>> I'm confused. Did you apply this on top of v1 by accident?
>> Hi,
>> According to my modified mm_vmscan_lru_shrink_inactive test tracelog, in the
> You're missing David's point. You've generated this patch against ...
> something ... that isn't upstream. Probably against v1 of your
> patch. Please check your git tree.
Yes, [PATCH v2 1/2] is against my patch v1 index 2cc0cb41fb32..cf555cdfcefc.
>
>> 32 scanned inactive file pages, 20 were dirty, and the 20 dirty pages were
>> not reclamed, but they took 20us to perform try_to_unmap.
>>
>> I think unreclaimed dirty folio in inactive file lru can skip to perform
>> try_to_unmap. Please help to continue review. Thanks.
>>
>> kswapd0-99 ( 99) [005] ..... 687.793724:
>> mm_vmscan_lru_shrink_inactive: [Justin] nid 0 scan=32 isolate=32 reclamed=12
>> nr_dirty=20 nr_unqueued_dirty=20 nr_writeback=0 nr_congested=0
>> nr_immediate=0 nr_activate[0]=0 nr_activate[1]=20 nr_ref_keep=0
>> nr_unmap_fail=0 priority=2 file=RECLAIM_WB_FILE|RECLAIM_WB_ASYNC total=39
>> exe=0 reference_cost=5 reference_exe=0 unmap_cost=21 unmap_exe=0
>> dirty_unmap_cost=20 dirty_unmap_exe=0 pageout_cost=0 pageout_exe=0
> Are you seeing measurable changes for any workloads? It certainly seems
> like you should, but it would help if you chose a test from mmtests and
> showed how performance changed on your system.
Powered by blists - more mailing lists