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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 8AF2A18000F X-Stat-Signature: 95reeqfygzy3k6r97ao5zwksiko5jiyk X-Rspam-User: X-Rspamd-Server: rspam09 X-HE-Tag: 1736323350-330033 X-HE-Meta: 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 i63KLOdC lk2+Ey0y+xi+9tVNgelAc5SKsB+e5W5StYrt6nqtpYdBbrDdnD75Aaaz84gJ8HjB8jXCU70NUiBvo1K0OyxWhAedj3/lvFpsM2H6pAO+teRyujAMT1zzgW9ekQd/0JBmguQYPgUMpwGYQn5b9AP5n/IOa0u+l/EXr099ZPcDVxFFKUKTZK/0y1m9NFB7HRQaTr9vi9ZDwYlVG7EBMjY8JQ9YLaQGx98HeiYKAITN2XzmkcQTG1vNU9gEJ7EBcxF1B1tNcPsk5yjKg61M= 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: List-Subscribe: List-Unsubscribe: On 08/01/2025 04:56, Andrew Morton wrote: > On Tue, 7 Jan 2025 14:25:53 +0000 Ryan Roberts wrote: > >> After commit b1f202060afe ("mm: remap unused subpages to shared zeropage >> when splitting isolated thp"), cow test cases involving swapping out >> THPs via madvise(MADV_PAGEOUT) started to be skipped due to the >> subsequent check via pagemap determining that the memory was not >> actually swapped out. Logs similar to this were emitted: >> >> ... >> >> The commit in question introduces the behaviour of scanning THPs and if >> their content is predominantly zero, it splits them and replaces the >> pages which are wholly zero with the zero page. These cow test cases >> were getting caught up in this. >> >> So let's avoid that by filling the contents of all allocated memory with >> a non-zero value. With this in place, the tests are passing again. >> > > Thanks, I'll add > > Fixes: b1f202060afe ("mm: remap unused subpages to shared zeropage when splitting isolated thp") Thanks, given it's not really a bug but a deliberate change of behaviour I wasn't sure that a Fixes tag was appropriate, but thanks for seting me straight. > ... > Cc: Usama Arif > Cc: Yu Zhao > Cc: