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Mon, 06 Oct 2025 17:35:39 -0700 (PDT) Date: Tue, 7 Oct 2025 00:35:39 +0000 From: Wei Yang To: Lance Yang Cc: akpm@linux-foundation.org, david@redhat.com, lorenzo.stoakes@oracle.com, ziy@nvidia.com, baolin.wang@linux.alibaba.com, Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, ioworker0@gmail.com, richard.weiyang@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH mm-new v2 2/3] mm/khugepaged: use VM_WARN_ON_FOLIO instead of VM_BUG_ON_FOLIO for non-anon folios Message-ID: <20251007003539.evunghgqxysojtr2@master> Reply-To: Wei Yang References: <20251006144338.96519-1-lance.yang@linux.dev> <20251006144338.96519-3-lance.yang@linux.dev> 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=us-ascii Content-Disposition: inline In-Reply-To: <20251006144338.96519-3-lance.yang@linux.dev> User-Agent: NeoMutt/20170113 (1.7.2) On Mon, Oct 06, 2025 at 10:43:37PM +0800, Lance Yang wrote: >From: Lance Yang > >As Zi pointed out, we should avoid crashing the kernel for conditions >that can be handled gracefully. Encountering a non-anonymous folio in an >anonymous VMA is a bug, but a warning is sufficient. > >This patch changes the VM_BUG_ON_FOLIO(!folio_test_anon(folio)) to a >VM_WARN_ON_FOLIO() in both __collapse_huge_page_isolate() and >hpage_collapse_scan_pmd(), and then aborts the scan with SCAN_PAGE_ANON. > >Making more of the scanning logic common between hpage_collapse_scan_pmd() >and __collapse_huge_page_isolate(), as suggested by Dev. > >Suggested-by: Dev Jain >Suggested-by: Zi Yan >Signed-off-by: Lance Yang Reviewed-by: Wei Yang -- Wei Yang Help you, Help me