Messages in this thread | | | Date | Tue, 1 Aug 2023 12:12:03 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH 1/5] mm/compaction: allow blockpfn outside of pageblock for high order buddy page |
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On Sun, 30 Jul 2023 01:43:50 +0800 Kemeng Shi <shikemeng@huaweicloud.com> wrote:
> Commit 9fcd6d2e052ee ("mm, compaction: skip compound pages by order in > free scanner") skiped compound pages to save iterations and limit blockpfn > to reach outside of page block in case of bogus compound_order. While this > also limit pfnblock outside page block in case a buddy page with order > higher than page block is found. After this, isolate_freepages_range will > fail unexpectedly as it will fail to isolate the page block which was > isolated successfully by high order buddy page in previous page block > and abort the free page isolation. > > Fix this by allow blockpfn outside of pageblock in case of high order > buddy page. > > ... > > @@ -1418,7 +1420,7 @@ fast_isolate_around(struct compact_control *cc, unsigned long pfn) > isolate_freepages_block(cc, &start_pfn, end_pfn, &cc->freepages, 1, false); > > /* Skip this pageblock in the future as it's full or nearly full */ > - if (start_pfn == end_pfn && !cc->no_set_skip_hint) > + if (start_pfn >= end_pfn && !cc->no_set_skip_hint) > set_pageblock_skip(page); > } >
This needed alteration for mm-unstable changes:
@@ -1441,7 +1443,7 @@ fast_isolate_around(struct compact_contr isolate_freepages_block(cc, &start_pfn, end_pfn, &cc->freepages, 1, false);
/* Skip this pageblock in the future as it's full or nearly full */ - if (start_pfn == end_pfn) + if (start_pfn >= end_pfn) set_pageblock_skip(page); return;
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