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t=1659736010; a=rsa-sha256; cv=pass; b=SjqJCang92Vh8lxonoO8HmDWpctgucJvdOaSwwX8tep9DT9PUfBrxvmFgfA/vHMxWMiwLu BGEXq7GdlBeuUHpNyJnwGXl/criA/IE6ewxmvEywTYtp6fUPN3WLqYHpLVmnQG7Z1YQg1Z Z0kuuGeZXxufhJpvJuPpKQMfGG8yiXA= Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=fb.com header.s=facebook header.b=lKpUDmKo; arc=pass ("microsoft.com:s=arcselector9901:i=1"); spf=pass (imf05.hostedemail.com: domain of "prvs=9216c36f05=alexlzhu@fb.com" designates 67.231.145.42 as permitted sender) smtp.mailfrom="prvs=9216c36f05=alexlzhu@fb.com"; dmarc=pass (policy=reject) header.from=fb.com X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: EB30D100142 X-Stat-Signature: kgwwkdowju7fptgdzq9coz9wr7yue4ac X-Rspam-User: X-HE-Tag: 1659736008-15687 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: >=20 > Out of curiosity, do you have any statistics on how much of a performance= impact scanning may have? >=20 > We've reached the point where we've finally been able to show previous ad= monitions to not enable THP due to a negative performance impact no longer = hold true, and I'd hate to see systems on which enabling THP now would caus= e a performance hit due to this scanner. There are no noticeable performance issues from running the scanner itself = from our experiments. As written, we check 256 pfn s at a time every second= , which does not appear to be an issue. =