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 C78A5C433F5 for ; Fri, 15 Apr 2022 19:03:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347838AbiDOTGS (ORCPT ); Fri, 15 Apr 2022 15:06:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347623AbiDOTGP (ORCPT ); Fri, 15 Apr 2022 15:06:15 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CA21FDA09A; Fri, 15 Apr 2022 12:03:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=6HzF+upEgux6jeyTUvqIhEFVqtPf6F78zI7LldDeVqo=; b=yOR8vjzmH9dv3TXNkWPHUr4Jo4 8p/N8wsEcAProi2PY1nAuUzmrT/uoMrQ5rnVUWfl9CPvrPXITuuwgasoCCJN8tG/FYy4CqonpUxWz 44PR5mqMuxhl1ohEfbDu3JBAErZ52ABZXbJMnpLwmaAFBEcHMffC2J2nEB8h8oCC1QTD5IbcAbM+7 itqZRblvkWnI3Au9UcLAkRneGaZRwTAJU2Fx7X2h1tlZoa+v8qFW6mEVrMJDajAlVu6ZgGwzyYyAm U3D6e3oI2F+2TkHsn4B+EQZ8+57fsTCUXgZFwtbnL98YVSzWr40b5HG0m6jazStHtme6QwZvPV6k3 /MW7zPpw==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nfREM-00B9WG-Bs; Fri, 15 Apr 2022 19:03:42 +0000 Date: Fri, 15 Apr 2022 12:03:42 -0700 From: Luis Chamberlain To: Song Liu Cc: Linus Torvalds , bpf , Linux-MM , open list , Alexei Starovoitov , Daniel Borkmann , Kernel Team , Andrew Morton , "Edgecombe, Rick P" , Christoph Hellwig , imbrenda@linux.ibm.com Subject: Re: [PATCH v3 bpf RESEND 3/4] module: introduce module_alloc_huge Message-ID: References: <20220414195914.1648345-1-song@kernel.org> <20220414195914.1648345-4-song@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: Luis Chamberlain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 14, 2022 at 02:31:18PM -0700, Song Liu wrote: > On Thu, Apr 14, 2022 at 2:11 PM Luis Chamberlain wrote: > > > > On Thu, Apr 14, 2022 at 02:03:17PM -0700, Song Liu wrote: > > > Hi Luis, > > > > > > On Thu, Apr 14, 2022 at 1:34 PM Luis Chamberlain wrote: > > > > > > > > On Thu, Apr 14, 2022 at 12:59:13PM -0700, Song Liu wrote: > > > > > Introduce module_alloc_huge, which allocates huge page backed memory in > > > > > module memory space. The primary user of this memory is bpf_prog_pack > > > > > (multiple BPF programs sharing a huge page). > > > > > > > > > > Signed-off-by: Song Liu > > > > > > > > See modules-next [0], as modules.c has been chopped up as of late. > > > > So if you want this to go throug modules this will need to rebased > > > > on that tree. fortunately the amount of code in question does not > > > > seem like much. > > > > > > > > [0] https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git/log/?h=modules-next > > > > > > We are hoping to ship this with to 5.18, as the set addresses some issue with > > > huge page backed vmalloc. I guess we cannot ship it via modules-next branch. > > > > > > > Huh, you intend this to go in as a fix for v5.18 (already released) once > > properly reviewed? This seems quite large... for a fix. > > > > > How about we ship module_alloc_huge() to 5.18 in module.c for now, and once > > > we update modules-next branch, I will send another patch to clean it up? > > > > I rather set the expectations right about getting such a large fix in > > for v5.18. I haven't even sat down to review all the changes in light of > > this, but a cursorary glance seems to me it's rather "large" for a fix. > > Yes, I agree this is a little too big for a fix. I guess we can discuss whether > some of the set need to wait until 5.19. Doing a more thorough review of this now, and when the other changes landed, it seems this is *large follow up fix* for an optimization for when tons of JIT eBPF programs are used. It's so large I can't be confident this also doesn't go in with other holes or issues, or that the other stuff merged already also has some other issues. So I can't see anything screaming for why this needs to go in for v5.18 other than it'd be nice. So my preference is for this to go through v5.19 as I see no rush. Luis