From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F0AFFC6FD1F for ; Wed, 15 Mar 2023 03:00:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230133AbjCODAw (ORCPT ); Tue, 14 Mar 2023 23:00:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40348 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229552AbjCODAv (ORCPT ); Tue, 14 Mar 2023 23:00:51 -0400 X-Greylist: delayed 393 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Tue, 14 Mar 2023 20:00:49 PDT Received: from out-19.mta1.migadu.com (out-19.mta1.migadu.com [95.215.58.19]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4CAAB4C6F4 for ; Tue, 14 Mar 2023 20:00:48 -0700 (PDT) Date: Tue, 14 Mar 2023 19:54:08 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1678848853; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ctapMItOIZsfzFhEc3JvdA9EOk3B6vYmM+FXjmAeKQk=; b=S85qHME5d8VThaKta/6fehQVWG3p4FqIiHEZ7d34QmY87G/pcECtJJwFnb0GrNF1AcFsGK mOIwaeJhFDmW5x9+foUp2O4Gx7CkBTROL7SDa8DENrRKpqTR2cfxh5sVlbFUXfPoHe1SEB /JNZs5CcbaqBFFxZIlUzCloMej+ZUr4= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Roman Gushchin To: Vlastimil Babka Cc: lsf-pc@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org, bpf@vger.kernel.org, linux-xfs@vger.kernel.org, David Rientjes , Christoph Lameter , Pekka Enberg , Joonsoo Kim , Hyeonggon Yoo <42.hyeyoo@gmail.com> Subject: Re: [LSF/MM/BPF TOPIC] SLOB+SLAB allocators removal and future SLUB improvements Message-ID: References: <4b9fc9c6-b48c-198f-5f80-811a44737e5f@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4b9fc9c6-b48c-198f-5f80-811a44737e5f@suse.cz> X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, Mar 14, 2023 at 09:05:13AM +0100, Vlastimil Babka wrote: > As you're probably aware, my plan is to get rid of SLOB and SLAB, leaving > only SLUB going forward. The removal of SLOB seems to be going well, there > were no objections to the deprecation and I've posted v1 of the removal > itself [1] so it could be in -next soon. > > The immediate benefit of that is that we can allow kfree() (and kfree_rcu()) > to free objects from kmem_cache_alloc() - something that IIRC at least xfs > people wanted in the past, and SLOB was incompatible with that. > > For SLAB removal I haven't yet heard any objections (but also didn't > deprecate it yet) but if there are any users due to particular workloads > doing better with SLAB than SLUB, we can discuss why those would regress and > what can be done about that in SLUB. > > Once we have just one slab allocator in the kernel, we can take a closer > look at what the users are missing from it that forces them to create own > allocators (e.g. BPF), and could be considered to be added as a generic > implementation to SLUB. I guess eventually we want to merge the percpu allocator too.