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dkim=pass header.d=Nvidia.com header.s=selector2 header.b=jlTOEkWh; spf=none (imf07.hostedemail.com: domain of jgg@nvidia.com has no SPF policy when checking 40.107.237.72) smtp.mailfrom=jgg@nvidia.com; dmarc=pass (policy=quarantine) header.from=nvidia.com X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 566C710004D9 X-Stat-Signature: 9g5wtr41n5kkujmfqr8kibwe15urbbqo X-HE-Tag: 1636566567-431915 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: On Wed, Nov 10, 2021 at 06:37:46PM +0100, David Hildenbrand wrote: > It will be if we somewhat frequent when reclaim an empty PTE page table > as soon as it turns empty. What do you think is the frequency of unlocked page table walks that this would have to block on? > Also, it adds complexity for something that is only a problem in some > corner cases -- sparse memory mappings, especially relevant for some > memory allocators after freeing a lot of memory or running VMs with > memory ballooning after inflating the balloon. Some of these use cases > might be good with just triggering page table reclaim manually from user > space. Right, this is why it would be nice if the complexity could address more than one problem, like the existing complex locking around the thp stuff.. Jason