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Mon, 30 Mar 2026 09:49:09 -0700 (PDT) Received: from [2a00:79e0:2eb0:8:bec3:8e5e:fca2:7852] ([2a00:79e0:2eb0:8:bec3:8e5e:fca2:7852]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-35d9507d505sm7423298a91.10.2026.03.30.09.49.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 30 Mar 2026 09:49:08 -0700 (PDT) Date: Mon, 30 Mar 2026 09:49:08 -0700 (PDT) From: David Rientjes To: "Harry Yoo (Oracle)" cc: Vlastimil Babka , Andrew Morton , Hao Li , Christoph Lameter , Roman Gushchin , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH V1 2/2] lib/tests/slub_kunit: add a test case for {kmalloc,kfree}_nolock In-Reply-To: <20260330120517.104743-3-harry@kernel.org> Message-ID: <41823aa6-28e4-e57c-6a6e-fd6a8235462b@google.com> References: <20260330120517.104743-1-harry@kernel.org> <20260330120517.104743-3-harry@kernel.org> 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 On Mon, 30 Mar 2026, Harry Yoo (Oracle) wrote: > Testing invocation of {kmalloc,kfree}_nolock() during kmalloc() or > kfree() is tricky, and it is even harder to ensure that slowpaths are > properly tested. Lack of such testing has led to late discovery of > the bug fixed by commit a1e244a9f177 ("mm/slab: use prandom if > !allow_spin"). > > Add a slub_kunit test that allocates and frees objects in a tight loop > while a perf event triggers NMIs on the same task, invoking > {kmalloc,kfree}_nolock() from the NMI handler. > > Signed-off-by: Harry Yoo (Oracle) Acked-by: David Rientjes