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Harding" , Andrew Morton , Christoph Lameter , Pekka Enberg , Joonsoo Kim , Tejun Heo , Qian Cai , Linus Torvalds , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Mel Gorman Subject: Re: [PATCH 0/1] mm: Remove the SLAB allocator In-Reply-To: Message-ID: References: <20190410024714.26607-1-tobin@kernel.org> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 10 Apr 2019, Vlastimil Babka wrote: > On 4/10/19 4:47 AM, Tobin C. Harding wrote: > > Recently a 2 year old bug was found in the SLAB allocator that crashes > > the kernel. This seems to imply that not that many people are using the > > SLAB allocator. > > AFAIK that bug required CONFIG_DEBUG_SLAB_LEAK, not just SLAB. That > seems to imply not that many people are using SLAB when debugging and > yeah, SLUB has better debugging support. But I wouldn't dare to make the > broader implication :) > > > Currently we have 3 slab allocators. Two is company three is a crowd - > > let's get rid of one. > > > > - The SLUB allocator has been the default since 2.6.23 > > Yeah, with a sophisticated reasoning :) > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a0acd820807680d2ccc4ef3448387fcdbf152c73 > > > - The SLOB allocator is kinda sexy. Its only 664 LOC, the general > > design is outlined in KnR, and there is an optimisation taken from > > Knuth - say no more. > > > > If you are using the SLAB allocator please speak now or forever hold your peace ... > > FWIW, our enterprise kernel use it (latest is 4.12 based), and openSUSE > kernels as well (with openSUSE Tumbleweed that includes latest > kernel.org stables). AFAIK we don't enable SLAB_DEBUG even in general > debug kernel flavours as it's just too slow. > > IIRC last time Mel evaluated switching to SLUB, it wasn't a clear > winner, but I'll just CC him for details :) > We also use CONFIG_SLAB and disable CONFIG_SLAB_DEBUG for the same reason.