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Fri, 2 Feb 2024 12:57:36 +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 OwcUH8DmvGX6CAAAD6G6ig (envelope-from ); Fri, 02 Feb 2024 12:57:36 +0000 Date: Fri, 2 Feb 2024 13:57:35 +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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Authentication-Results: smtp-out2.suse.de; none X-Spamd-Result: default: False [0.12 / 50.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; 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]; RCVD_COUNT_THREE(0.00)[3]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; RCPT_COUNT_SEVEN(0.00)[10]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:email]; 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(-0.28)[74.18%] X-Spam-Level: X-Spam-Flag: NO X-Spam-Score: 0.12 On Fri 02-02-24 20:52:48, Lance Yang wrote: > On Fri, Feb 2, 2024 at 8:27 PM Michal Hocko wrote: > > > > On Fri 02-02-24 19:18:31, Lance Yang wrote: > > > IMO, since it's treated the same as pte_none, > > > perhaps lazyfree pages shouldn't be copied to > > > the new huge page. > > > > Why? The content of MADV_FREE page is valid until it is reclaimed. > > IMO, if MADV_FREE pages are considered valid until > reclaimed, treating them the same as pte_none might > pose a conflict. What kind of conflict? -- Michal Hocko SUSE Labs