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 X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 311F9C433E0 for ; Wed, 20 Jan 2021 10:11:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id AB5F22332A for ; Wed, 20 Jan 2021 10:11:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AB5F22332A Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 419566B0006; Wed, 20 Jan 2021 05:11:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3CA1C6B0007; Wed, 20 Jan 2021 05:11:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2E0276B0008; Wed, 20 Jan 2021 05:11:15 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0189.hostedemail.com [216.40.44.189]) by kanga.kvack.org (Postfix) with ESMTP id 195916B0006 for ; Wed, 20 Jan 2021 05:11:15 -0500 (EST) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id D5FCA1EF1 for ; Wed, 20 Jan 2021 10:11:14 +0000 (UTC) X-FDA: 77725735668.19.scarf57_210908c27559 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin19.hostedemail.com (Postfix) with ESMTP id AF4DB1ACC27 for ; Wed, 20 Jan 2021 10:11:14 +0000 (UTC) X-HE-Tag: scarf57_210908c27559 X-Filterd-Recvd-Size: 4884 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf35.hostedemail.com (Postfix) with ESMTP for ; Wed, 20 Jan 2021 10:11:14 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1611137473; h=from:from:reply-to: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=f85nyV30dGUYyT4OSwZQuD/tNzi1TVhqdVBME5I7U34=; b=Tqtkk73BVvR1GyvLqKN8ezpgmILoSEhpUbnhuP+3EYhk+CP5v9bOCWEbAYqu7lzOemwRDX Y4lmzrHaj6x3fJ6JJrwa92jIVJWUqquupWpWBxfWJ4kEZcUuWCL+wHAKVU0cMlyQwdVDRJ FQANm4sJYUPgLnNrgjrxdQNSlQcFIao= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 1D056AC8F; Wed, 20 Jan 2021 10:11:13 +0000 (UTC) Date: Wed, 20 Jan 2021 11:11:12 +0100 From: Michal Hocko To: Dan Williams Cc: akpm@linux-foundation.org, David Hildenbrand , Oscar Salvador , linux-mm@kvack.org, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 1/5] mm: Move pfn_to_online_page() out of line Message-ID: <20210120101112.GF9371@dhcp22.suse.cz> References: <161058499000.1840162.702316708443239771.stgit@dwillia2-desk3.amr.corp.intel.com> <161058499608.1840162.10165648147615238793.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <161058499608.1840162.10165648147615238793.stgit@dwillia2-desk3.amr.corp.intel.com> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed 13-01-21 16:43:16, Dan Williams wrote: > pfn_to_online_page() is already too large to be a macro or an inline > function. In anticipation of further logic changes / growth, move it out > of line. > > No functional change, just code movement. > > Reported-by: Michal Hocko I am not sure what r-b refers to. I suspect it is the overal problem rather than this particular patch. Not that I care much but it might get confusing because I do not remember ever complaining about pfn_to_online_page to be too large. > Reviewed-by: David Hildenbrand > Reviewed-by: Oscar Salvador > Signed-off-by: Dan Williams I do not remember any hot path which depends on pfn walk and a function call would be clearly visible. If this ever turn out to be a problem we can make it inline and push the heavy lifting out of line. Acked-by: Michal Hocko Thanks! > --- > include/linux/memory_hotplug.h | 17 +---------------- > mm/memory_hotplug.c | 16 ++++++++++++++++ > 2 files changed, 17 insertions(+), 16 deletions(-) > > diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h > index 15acce5ab106..3d99de0db2dd 100644 > --- a/include/linux/memory_hotplug.h > +++ b/include/linux/memory_hotplug.h > @@ -16,22 +16,7 @@ struct resource; > struct vmem_altmap; > > #ifdef CONFIG_MEMORY_HOTPLUG > -/* > - * Return page for the valid pfn only if the page is online. All pfn > - * walkers which rely on the fully initialized page->flags and others > - * should use this rather than pfn_valid && pfn_to_page > - */ > -#define pfn_to_online_page(pfn) \ > -({ \ > - struct page *___page = NULL; \ > - unsigned long ___pfn = pfn; \ > - unsigned long ___nr = pfn_to_section_nr(___pfn); \ > - \ > - if (___nr < NR_MEM_SECTIONS && online_section_nr(___nr) && \ > - pfn_valid_within(___pfn)) \ > - ___page = pfn_to_page(___pfn); \ > - ___page; \ > -}) > +struct page *pfn_to_online_page(unsigned long pfn); > > /* > * Types for free bootmem stored in page->lru.next. These have to be in > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index f9d57b9be8c7..55a69d4396e7 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -300,6 +300,22 @@ static int check_hotplug_memory_addressable(unsigned long pfn, > return 0; > } > > +/* > + * Return page for the valid pfn only if the page is online. All pfn > + * walkers which rely on the fully initialized page->flags and others > + * should use this rather than pfn_valid && pfn_to_page > + */ > +struct page *pfn_to_online_page(unsigned long pfn) > +{ > + unsigned long nr = pfn_to_section_nr(pfn); > + > + if (nr < NR_MEM_SECTIONS && online_section_nr(nr) && > + pfn_valid_within(pfn)) > + return pfn_to_page(pfn); > + return NULL; > +} > +EXPORT_SYMBOL_GPL(pfn_to_online_page); > + > /* > * Reasonably generic function for adding memory. It is > * expected that archs that support memory hotplug will -- Michal Hocko SUSE Labs