Re: [PATCH 0/2] make VM_SOFTDIRTY a sticky VMA flag
Cyrill Gorcunov <[email protected]> Wed, 19 Nov 2025 16:09:49 +0300
| Newsgroups | dev.linux.lists.criu,org.kernel.vger.linux-kernel,org.kvack.linux-mm |
|---|---|
| Message-ID | <aR3BndGWuzf8vnku@grain> |
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 <[email protected]>