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From: Muchun Song In-Reply-To: <99eac2ba-a4e5-4885-aa81-b0c43f6fc4b2@iscas.ac.cn> Date: Tue, 7 Jul 2026 17:07:00 +0800 Cc: Alexandre Ghiti , Andrew Morton , David Hildenbrand , "Liam R. Howlett" , Lorenzo Stoakes , Michal Hocko , Mike Rapoport , Palmer Dabbelt , Paul Walmsley , Suren Baghdasaryan , Vlastimil Babka , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org Content-Transfer-Encoding: 7bit Message-Id: <77B0BBBA-0CDF-49F4-9B07-D35D0D864612@linux.dev> References: <20260707-mark-after-vmemmap-populate-v5-1-77d1ded3cae3@iscas.ac.cn> <99eac2ba-a4e5-4885-aa81-b0c43f6fc4b2@iscas.ac.cn> To: Vivian Wang X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 9708940005 X-Stat-Signature: h7kqhx8j9g4tbzfw8t7mc6yj6uimxs37 X-HE-Tag: 1783415259-194417 X-HE-Meta: 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 SIvATD/Y UGIYlNz3GM1ViArP25lfYdKitA7mjGrPOF6up2EUfrM8AEQr3wT74joRnfPFqldlAZXQqi3Oz357Hd5pz+35ZwTJ10+iR5cCG1BC81ppVE5dzBy0yOWpWAuRkRW7g3qFpAPUGNzN7IiCmCHBZKFhGwlhb2jRQsoNIJXGd+Um+SULHpkWBYTR5T759TTBY1s9A6cJ1DigUNoFQ/0o0nv+r4CxRiyD04jOg86vnr4tkC55t6Qk+0FS7yTIKEtVEg88FBRDkR2W2NHdZCNl+c72qSIvB2Sczr4BPJ1+F Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > On Jul 7, 2026, at 13:03, Vivian Wang wrote: > > Please disregard. I made a mistake while submitting this patch. > > I'll send a fixed v6 later. Sorry. Please fix issues reported by Sashiko excluding pre-existing ones. Thanks. > > On 7/7/26 12:10, Vivian Wang wrote: >> section_activate() does not flush TLB after populating new vmemmap >> pages. On most architectures, this is okay. However it is a problem on >> RISC-V since there the TLB caching non-present entries is permitted, >> which causes spurious faults on some hardwares. >> >> This seems to be most easily reproduced with DEBUG_VM=y and >> PAGE_POISONING=y, which causes these newly mapped struct pages to be >> poisoned i.e. written to immediately after mapping. >> >> Extend the RISC-V flush_cache_vmap() to also handle the vmemmap range, >> and call it after hotplugging vmemmap, which gets the possible spurious >> fault handled in the exception handler. >> >> At least for now, the only other architecture with both >> SPARSEMEM_VMEMMAP and flush_cache_vmap() is PowerPC, which has a similar >> problem with newly valid PTEs. But there flush_cache_vmap() is just a >> ptesync. So it should be safe to do this for generic code while having >> minimal performance impact. >> >> Suggested-by: Muchun Song >> Signed-off-by: Vivian Wang >> --- > [...]