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Fri, 2 Feb 2024 15:38:49 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id 5RaJBokMvWXWMwAAD6G6ig (envelope-from ); Fri, 02 Feb 2024 15:38:49 +0000 Date: Fri, 2 Feb 2024 16:38:48 +0100 From: Michal Hocko To: Lance Yang Cc: akpm@linux-foundation.org, zokeefe@google.com, david@redhat.com, songmuchun@bytedance.com, shy828301@gmail.com, peterx@redhat.com, minchan@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/1] mm/khugepaged: skip copying lazyfree pages on collapse Message-ID: References: <20240201125226.28372-1-ioworker0@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Authentication-Results: smtp-out1.suse.de; dkim=pass header.d=suse.com header.s=susede1 header.b="JE3/OF6P" X-Spamd-Result: default: False [-2.13 / 50.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; R_DKIM_ALLOW(-0.20)[suse.com:s=susede1]; SPAMHAUS_XBL(0.00)[2a07:de40:b281:104:10:150:64:97:from]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; DWL_DNSWL_BLOCKED(0.00)[suse.com:dkim]; RCVD_COUNT_THREE(0.00)[3]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; DKIM_TRACE(0.00)[suse.com:+]; MX_GOOD(-0.01)[]; RCPT_COUNT_SEVEN(0.00)[10]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:dkim]; FREEMAIL_TO(0.00)[gmail.com]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; MID_RHS_NOT_FQDN(0.50)[]; FREEMAIL_CC(0.00)[linux-foundation.org,google.com,redhat.com,bytedance.com,gmail.com,kernel.org,kvack.org,vger.kernel.org]; RCVD_TLS_ALL(0.00)[]; BAYES_HAM(-2.32)[96.85%] X-Rspamd-Server: rspamd1.dmz-prg2.suse.org X-Rspamd-Queue-Id: 3D71021E95 X-Spam-Level: X-Spam-Score: -2.13 X-Spam-Flag: NO On Fri 02-02-24 22:52:49, Lance Yang wrote: > How about blocking khugepaged from > collapsing lazyfree pages? This way, > is it not better to keep the semantics > of MADV_FREE? I do not see any reason why. And you are not providing any actual reasoning either. Unless you have a very specific example in mind I do not think we want to change the current behavior. -- Michal Hocko SUSE Labs