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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jann Horn , Pedro Falcato , linux-mm@kvack.org, linux-kernel@vger.kernel.org, criu@lists.linux.dev Subject: Re: [PATCH 0/2] make VM_SOFTDIRTY a sticky VMA flag Message-ID: References: <1c20ec44-0775-47e0-aabb-e1cf1f38ce94@lucifer.local> Precedence: bulk X-Mailing-List: criu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/2.2.14 (2025-02-20) On Mon, Nov 17, 2025 at 07:57:30PM +0000, Lorenzo Stoakes wrote: ... > > I recall correctly that initially, merging vma-s with different > > VM_SORTDIRTY bit values was not allowed. It was a bit surprising that > > this behavior was changed by Cyrill in 34228d473efe. Cyrill was an > > active CRIU contributor at the time, so we can't even blame anyone for > > breaking CRIU :). > > Well I think Cyrill is in the right here :) the problem described there - > that of hitting the max_map_count simply due to failed VM_SOFTDIRTY merges > - is very serious and clearly highlights the issue that arises from not > merging these - that is VMA fragmentation. Hi guys! Happen to miss this thread due to high message traffic, thanks for CC'ing me ;) Yeah, disability to merge VMAs due to softdirty bit has been a serious issue, so better criu to dump more (redundant) memory than apps got broken. As to this patch series, I think it is good, thanks a huge Lorenzo! Acked-by: Cyrill Gorcunov