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charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20230901155141.249860-4-shikemeng@huaweicloud.com> X-Rspamd-Queue-Id: A7BB0140004 X-Rspam-User: X-Stat-Signature: dbe1bkp8a31xkxpfbnmqgri1kzmnmi1c X-Rspamd-Server: rspam03 X-HE-Tag: 1693559835-422905 X-HE-Meta: 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 4ryk2lQE XM+ievLB8+lTFEM5McutiwGISRpSU1B/slPEHB4xtP+RvIpPiEoyY/CZ1AjB/1DYRwk/MSbrQ/0Z6MyCrjS12fbfI6aKlPN9AKY0DvpgroBqvZV0pwTCUAa4Ptik3DOJWwRBI22F7ZHl8CpW2PFddUk9J3BqQ1vxDDfWro/BBoD3dAWU+tNAQB2YmTZHZwwm3EWJ7SNX+CGfc+XwPDrqhVxoHkDT0lwr+LmE3d8iSYYPMR2pyi0KUQKZGqS3YoCOsNcPktMxiiz8Q3a+3X6NKsq2jTRv6XVf4AaunWu6Yo12QCik= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Sep 01, 2023 at 11:51:38PM +0800, Kemeng Shi wrote: > In strict mode, we should return 0 if there is any hole in pageblock. If > we successfully isolated pages at beginning at pageblock and then have a > bogus compound_order outside pageblock in next page. We will abort search > loop with blockpfn > end_pfn. Although we will limit blockpfn to end_pfn, > we will treat it as a successful isolation in strict mode as blockpfn is > not < end_pfn and return partial isolated pages. Then > isolate_freepages_range may success unexpectly with hole in isolated > range. > > Fixes: 9fcd6d2e052e ("mm, compaction: skip compound pages by order in free scanner") > Signed-off-by: Kemeng Shi > Reviewed-by: Baolin Wang > --- > mm/compaction.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/mm/compaction.c b/mm/compaction.c > index a40550a33aee..9ecbfbc695e5 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -626,11 +626,12 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, > if (PageCompound(page)) { > const unsigned int order = compound_order(page); > > - if (likely(order <= MAX_ORDER)) { > + if (blockpfn + (1UL << order) <= end_pfn) { > blockpfn += (1UL << order) - 1; > page += (1UL << order) - 1; > nr_scanned += (1UL << order) - 1; > } > + > goto isolate_fail; > } > > @@ -678,8 +679,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, > spin_unlock_irqrestore(&cc->zone->lock, flags); > > /* > - * There is a tiny chance that we have read bogus compound_order(), > - * so be careful to not go outside of the pageblock. > + * Be careful to not go outside of the pageblock. > */ > if (unlikely(blockpfn > end_pfn)) > blockpfn = end_pfn; Is this check still necessary after the first hunk? -- Mel Gorman SUSE Labs