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[173.79.60.52]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-532eaec185esm21362971cf.3.2026.09.23.07.44.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 23 Sep 2026 07:44:19 -0700 (PDT) Date: Wed, 23 Sep 2026 10:44:17 -0400 From: Gregory Price To: "Lorenzo Stoakes (ARM)" Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, kernel-team@meta.com, akpm@linux-foundation.org, liam@infradead.org, david@kernel.org, vbabka@kernel.org, jannh@google.com, rppt@kernel.org, surenb@google.com, mhocko@suse.com, shuah@kernel.org Subject: Re: [PATCH 01/10] selftests/mm: exercise MADV_COLD and MADV_PAGEOUT Message-ID: References: <20260922235830.2350770-1-gourry@gourry.net> <20260922235830.2350770-2-gourry@gourry.net> 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: On Wed, Sep 23, 2026 at 03:26:05PM +0100, Lorenzo Stoakes (ARM) wrote: > > I think in general we want to avoid putting stress tests as part of the > selftests in general? Or at least if they might take a long time to run or > excessive memory usage, etc. > > Though that might be benchmarks, as we have the THP stress tests so maybe it's > OK? > > > > > Assisted-by: LLM > > Signed-off-by: Gregory Price (Meta) > > In any case I really do think this should be split out into smaller parts, this > is a _gigantic_ change :) > Absolutely, but alas my poor email hosting throttles me if i send too many emails - and sending a 38-part series where the important part is the endpoint of the refactor moreso than the individual tests... instant 24-hour timeout. I'm working on a solution. Need better hosting. > Since you list a whole bunch of different test areas and you're exercising > different things you should be able to split this out logically across those I > think? As mentioned, this was originally ~28 patches split out, but i think ultimately only the contractual tests should be shipped. Maybe there's an argument for keeping some of the implementation details - they're fairly easy to find in the code below for individual inspection. Examples contractual: These tests won't change behavior based on implementation - authorized file PAGEOUT evicts a clean file page; - unauthorized shared-file PAGEOUT leaves the page resident; and - private-file PAGEOUT reclaims a COW page but preserves a file page. implementation detail: behavior can change without breaking a contract - full and partial MADV_COLD on a PTE-mapped THP ~Gregory