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t=1789739245; bh=zDB8ZNrlloa4K4BhhwSa+v9ApPYQhDBrcYUmm+5KlB4=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=F9ZUhBUHGtWbiYQJVewlMYWp6udci2KIiFZLV4F7Cxb0UcEtK9ErRh/K0jtkgbpzi 8czAX5BPGeqlacdyzDKafNHDHbtZdPv/ngZU5UcI/ERMTB6iwzpB+mnt7/iD+PIK52 Aw0IVWIxLOeb6jZwmtaCrvYB9AGdTS1qEFBeekYfe8GxFz7IvfsHeJD6nVvO6hfsgK MHj2AspFZHalCqpmD0C2+zmzFZEOyMbCRyR6x6awZa1lZNc+YvYIM3isj9p1OyGjzd YqhPXY5IEKN/uyEGBcjf1b7m6sLMKamDtFfnF/AfWv1ncitJ5NNZbvfK4UBXQKGaJi Nq3A15d1BYm5w== Message-ID: <813a2644-fa9f-4ee7-8655-ca69ef0e8a98@kernel.org> Date: Fri, 18 Sep 2026 15:47:18 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v9 11/15] filemap: Add hwpoison handling to filemap_read() To: Matthew Wilcox , Pedro Falcato Cc: Andrew Morton , Jane Chu , linux-mm@kvack.org, Muchun Song , Oscar Salvador , Miaohe Lin , Naoya Horiguchi , Jan Kara , linux-fsdevel@vger.kernel.org, Christian Brauner , Jiaqi Yan References: <20260805210557.1118966-1-willy@infradead.org> <20260805210557.1118966-12-willy@infradead.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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>>> + size_t safe_bytes; >> offset >> PAGE_SHIFT would probably be more idiomatic > > $ git grep '/ PAGE_SIZE' mm fs |wc -l > 116 > $ git grep '>> PAGE_SHIFT' mm fs |wc -l > 656 > > it seems relatively common. Personally I find / easier to understand > because I sometimes get confused between left and right shifts. I > don't think I've ever been confused between multiply and divide ;-) Linus once explained why ">> PAGE_SHIFT" is preferable when the type of the function might be signed, as the shift generates better code. I personally find "offset / PAGE_SIZE" more intuitive, but I also have sympathy for PHYS_PFN() to abstract the operation. (SIZE_TO_PAGES would be a bit mouthful so I wouldn't ever dare suggesting to introduce a new helper) -- Cheers, David