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([2620:10d:c090:600::1:fe53]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-2ee90748a61sm6341601a91.52.2024.12.03.13.06.28 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 03 Dec 2024 13:06:28 -0800 (PST) Message-ID: <668f271f-dc44-49e1-b8dc-08e65e1fec23@kernel.dk> Date: Tue, 3 Dec 2024 14:06:27 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCHSET v6 0/12] Uncached buffered IO To: "Christoph Lameter (Ampere)" Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, hannes@cmpxchg.org, clm@meta.com, linux-kernel@vger.kernel.org, willy@infradead.org, kirill@shutemov.name, bfoster@redhat.com References: <20241203153232.92224-2-axboe@kernel.dk> Content-Language: en-US From: Jens Axboe In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 12/3/24 11:23 AM, Christoph Lameter (Ampere) wrote: > On Tue, 3 Dec 2024, Jens Axboe wrote: > >> >> So here's a new approach to the same concent, but using the page cache >> as synchronization. That makes RWF_UNCACHED less special, in that it's >> just page cache IO, except it prunes the ranges once IO is completed. > > > Great idea and someting that is really important these days. > > However, one nit that I have is the use of the term "uncached" for a > folio/page. An uncached "page frame" refers to a page frame that requires > accesses not going through the cpu cache. I.e. device mappings. This is > an established mm/cpu term as far as I can tell. > > So maybe be a bit more specific about which cache this is? > > PAGE_CACHE_UNCACHED? > > or use a different term. It is cached after all but only for a brief > period. So this may be a "TEMPORAL_PAGE" or so? (Similar to the x86 > "non-temporal" stores). I actually did consider using some form of temporal, as it's the only other name I liked. But I do think cached_uncached becomes pretty unwieldy. Which is why I just stuck with uncached. Yes I know it means different things in different circles, but probably mostly an overlap with deeper technical things like that. An honestly almost impossible to avoid overlap these days, everything has been used already :-) IOW, I think uncached is probably still the most descriptive thing out there, even if I'm certainly open to entertaining other names. Just not anything yet that has really resonated with me. -- Jens Axboe