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 0295FC433F5 for ; Tue, 7 Dec 2021 11:27:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235683AbhLGLa7 (ORCPT ); Tue, 7 Dec 2021 06:30:59 -0500 Received: from mga05.intel.com ([192.55.52.43]:59560 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231221AbhLGLa6 (ORCPT ); Tue, 7 Dec 2021 06:30:58 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10190"; a="323811554" X-IronPort-AV: E=Sophos;i="5.87,293,1631602800"; d="scan'208";a="323811554" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Dec 2021 03:27:28 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,293,1631602800"; d="scan'208";a="679411624" Received: from irvmail001.ir.intel.com ([10.43.11.63]) by orsmga005.jf.intel.com with ESMTP; 07 Dec 2021 03:27:25 -0800 Received: from newjersey.igk.intel.com (newjersey.igk.intel.com [10.102.20.203]) by irvmail001.ir.intel.com (8.14.3/8.13.6/MailSET/Hub) with ESMTP id 1B7BROmr011993; Tue, 7 Dec 2021 11:27:24 GMT From: Alexander Lobakin To: Nick Desaulniers Cc: Alexander Lobakin , Andrew Morton , Arnd Bergmann , Nathan Chancellor , Zhen Lei , linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [PATCH] numa: mark __next_node() as __always_inline to fix section mismatch Date: Tue, 7 Dec 2021 12:27:09 +0100 Message-Id: <20211207112709.4778-1-alexandr.lobakin@intel.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nick Desaulniers Date: Mon, 6 Dec 2021 16:41:00 -0800 > On Mon, Dec 6, 2021 at 12:57 PM Alexander Lobakin > wrote: > > > > From: Nick Desaulniers > > Date: Mon, 6 Dec 2021 11:43:47 -0800 > > > > > On Mon, Dec 6, 2021 at 8:19 AM Alexander Lobakin > > > wrote: > > > > > > > > Clang (13) uninlines __next_node() which emits the following warning > > > > due to that this function is used in init code (amd_numa_init(), > > > > sched_init_numa() etc.): > > > > > > > > WARNING: modpost: vmlinux.o(.text+0x927ee): Section mismatch > > > > in reference from the function __next_node() to the variable > > > > .init.data:numa_nodes_parsed > > > > The function __next_node() references > > > > the variable __initdata numa_nodes_parsed. > > > > This is often because __next_node lacks a __initdata > > > > annotation or the annotation of numa_nodes_parsed is wrong. > > > > > > > > Mark __next_node() as __always_inline() so it won't get uninlined. > > > > bloat-o-meter over x86_64 binaries says this: > > > > > > > > scripts/bloat-o-meter -c vmlinux.baseline vmlinux > > > > add/remove: 1/1 grow/shrink: 2/7 up/down: 446/-2166 (-1720) > > > > Function old new delta > > > > apply_wqattrs_cleanup - 410 +410 > > > > amd_numa_init 814 842 +28 > > > > sched_init_numa 1338 1346 +8 > > > > find_next_bit 38 19 -19 > > > > __next_node 45 - -45 > > > > apply_wqattrs_prepare 1069 799 -270 > > > > wq_nice_store 688 414 -274 > > > > wq_numa_store 805 433 -372 > > > > wq_cpumask_store 789 402 -387 > > > > apply_workqueue_attrs 538 147 -391 > > > > workqueue_set_unbound_cpumask 947 539 -408 > > > > Total: Before=14422603, After=14420883, chg -0.01% > > > > > > > > So it's both win-win in terms of resolving section mismatch and > > > > saving some text size (-1.7 Kb is quite nice). > > > > > > > > Signed-off-by: Alexander Lobakin > > > > > > Thanks for the patch. See this thread: > > > https://github.com/ClangBuiltLinux/linux/issues/1302 > > > > > > There's a lot more instances of these based on config. Something like > > > https://github.com/ClangBuiltLinux/linux/issues/1302#issuecomment-807260475 > > > would be more appropriate for fixing all instances, but I think this > > > is more so an issue with the inline cost model in LLVM. > > > > > > I need to finish off https://reviews.llvm.org/D111456, and request > > > that https://reviews.llvm.org/D111272 which landed in clang-14 get > > > backported to the 13.0.1 release which should also help. > > > > Oh I see. Sorry for redundant posting, non-applicable then. > > No worries; it's a complex issue. I appreciate that you took the time > to test with clang, understand the issue, and send a patch. > ++beers_owed; Cool, thank you! :D Open source beer is shared across all contributors I guess :P > If you'd like, I can add you to our github org if you'd like to be > cc'ed on issues there; just ping me privately off thread with your > github account and I'll add you. > https://github.com/ClangBuiltLinux I think my private (non-Intel) account is added to it (it probably was you who added me after my comments on ClangCFI x86 or so), so I'll just be watching for it there, thanks! > > We'll wait for these Clang/LLVM works to be finised, thanks! > > > > > > > > > --- > > > > include/linux/nodemask.h | 2 +- > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h > > > > index 567c3ddba2c4..55ba2c56f39b 100644 > > > > --- a/include/linux/nodemask.h > > > > +++ b/include/linux/nodemask.h > > > > @@ -266,7 +266,7 @@ static inline int __first_node(const nodemask_t *srcp) > > > > } > > > > > > > > #define next_node(n, src) __next_node((n), &(src)) > > > > -static inline int __next_node(int n, const nodemask_t *srcp) > > > > +static __always_inline int __next_node(int n, const nodemask_t *srcp) > > > > { > > > > return min_t(int,MAX_NUMNODES,find_next_bit(srcp->bits, MAX_NUMNODES, n+1)); > > > > } > > > > -- > > > > 2.33.1 > > > > > > > > > > > > > -- > > > Thanks, > > > ~Nick Desaulniers > > > > Al > > > > > -- > Thanks, > ~Nick Desaulniers Al