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[209.85.208.43]) by smtp.gmail.com with ESMTPSA id w26-20020a170906385a00b00a4394f052cesm5125520ejc.150.2024.03.04.10.32.42 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 04 Mar 2024 10:32:42 -0800 (PST) Received: by mail-ed1-f43.google.com with SMTP id 4fb4d7f45d1cf-5649c25369aso6851804a12.2 for ; Mon, 04 Mar 2024 10:32:42 -0800 (PST) X-Forwarded-Encrypted: i=1; AJvYcCXsSD97ybb55gAHx7mYZN1ctG/V4lcqp/5G4NwlAneX65auyyIW9cEbImmKNqSMNIHCGDl+QN+8YiLFMCTdMvDqPSM= X-Received: by 2002:a17:906:8da:b0:a3f:ab4d:f7e3 with SMTP id o26-20020a17090608da00b00a3fab4df7e3mr7570338eje.0.1709577161818; Mon, 04 Mar 2024 10:32:41 -0800 (PST) MIME-Version: 1.0 References: <20230925120309.1731676-1-dhowells@redhat.com> <20230925120309.1731676-8-dhowells@redhat.com> <4e80924d-9c85-f13a-722a-6a5d2b1c225a@huawei.com> <769021.1709553367@warthog.procyon.org.uk> In-Reply-To: <769021.1709553367@warthog.procyon.org.uk> From: Linus Torvalds Date: Mon, 4 Mar 2024 10:32:25 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [bug report] dead loop in generic_perform_write() //Re: [PATCH v7 07/12] iov_iter: Convert iterate*() to inline funcs To: David Howells Cc: Tong Tiangen , Al Viro , Jens Axboe , Christoph Hellwig , Christian Brauner , David Laight , Matthew Wilcox , Jeff Layton , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Kefeng Wang Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: B8012180006 X-Rspam-User: X-Stat-Signature: ck9wppw3p4nqtd8sq817oyqyr3kbprrj X-Rspamd-Server: rspam01 X-HE-Tag: 1709577165-981479 X-HE-Meta: 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 2PMIxYaL BCVSDNGlK7dO8fjl5FJBWTIxmzgf31gijvIze8A9l7sdk1GXFuzb7Vq2elb7IU0wWH5OCF1wMgKxIVTKHU8n/T8msFbfOgq3wntJAv/S1yqxmhwubzi/LGh6Idn8nXtdHF7JwCJnF+ih/pR1MysiMyHcp1VzKBNC8Pf+MNB5wW1TkieUXWO0ckp9nchJ9PItWUBZTEgih8R+QUTd0FuACTEvpoiADtz36ekN4tSByNMsBOpHV9/IVXwxBTi/zDKmWKOCKTe5jMuLPiuTT9+k4sEuqk+WMqxCgs9AZJ+HNm2mP/qGCqKrBVLYip7S03LITGiBX 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: List-Subscribe: List-Unsubscribe: On Mon, 4 Mar 2024 at 03:56, David Howells wrote: > > That said, I wonder if: > > #ifdef copy_mc_to_kernel > > should be: > > #ifdef CONFIG_ARCH_HAS_COPY_MC Hmm. Maybe. We do have that #ifdef copy_mc_to_kernel pattern already in , so clearly we've done it both ways. I personally like the "just test for the thing you are using" model, which is then why I did it that way, but I don't have hugely strong opinions on it. > and whether it's possible to find out dynamically if MCEs can occur at all. I really wanted to do something like that, and look at the source page to decide "is this a pmem page that can cause machine checks", but I didn't find any obvious way to do that. Improvement suggestions more than welcome. Linus