From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6971A3909A8 for ; Wed, 24 Jun 2026 07:16:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782285419; cv=none; b=W224KwOiwJiN87B1TT9Ve4YTMGprT/c/7kPv47G9+YOMCU6oazpp+Odffr/m+Bxwl/2h1C7NSBhFqg0rwV4tpOF7yubYkfr2dTyJvmjplsH49gDQI8knIFLieOY5VBUG3EGvAAg2NsmgI8upPZeZoAihgTpJqF0TGwrYW3I/lt0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782285419; c=relaxed/simple; bh=80TNaSgv9m0Jg7gQN/z8T2DNw7htFj0qTbnLZW2FZEs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=gAYj9kBKlAvQMWC0G+2+TxVI2N4CEXZ2GBUbJQvpMRbXm7sc+4n/q9cvdmjMUWso3XI0CPtb/uakxVmmypuaxDyvYvys9EtuEd7dPj90mzttTfqO9J16ZssmxaqsmKGya9WFJx/JEVvLgICUnDfHvAwRXZYKUrfdvKjwjgqeqVw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ExvJXB+v; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ExvJXB+v" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E2BFF1F000E9; Wed, 24 Jun 2026 07:16:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782285418; bh=usD2Zx500l7YjzZfp5/jLk/wMudEX2pn65qPpLZCvzs=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=ExvJXB+v5NznZQBp47/Q5VjnJbVvyitW4di3uIhPLvqvcUgc+0z2B60yf1qVsE0dS BUv2KdmSEXT0OLlTb8OhsHIet/1JuqBI8oXmooSbHRQNWhRjf2s2inpLIvbr2ovr4c nC2Yfyeld4wL1wfguV0GM/qXAkvtjYMGSZecdQJtU/WvWhxPt/WIGjttI1w4PNzPtu KL08bQyeWdNhBNaEDoxBC4MtRoVJp6QDVd8JlSY2FdwtUrA6IoMb252Yi8f1etWfUz uOwWVf3zAuLp4lXfFUnZ18xOrSAT6kc2KDIspAy2xg2jNzcmiAh0VPYoNQurIANxrm 6vXjIg42fhAJg== Date: Wed, 24 Jun 2026 08:16:50 +0100 From: Lorenzo Stoakes To: akpm@linux-foundation.org Cc: Imran Khan , david@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/vmstat: avoid taking zone lock in /proc/buddyinfo reads Message-ID: References: <20260604134245.1580287-1-imran.f.khan@oracle.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260604134245.1580287-1-imran.f.khan@oracle.com> Hi Andrew, I think this one got missed last cycle? I don't see it in any mm- tree, and has a bunch of tags. I guess Imran will need to resend it at -rc1? Cheers, Lorenzo On Thu, Jun 04, 2026 at 09:42:45PM +0800, Imran Khan wrote: > frag_show_print() just reads zone->free_area[order].nr_free, so > it can safely do this without needing the zone->lock. > > Pass nolock=true from frag_show(), so that walk_zones_in_node() > can skip the zone->lock acquisition. > > Signed-off-by: Imran Khan > --- > mm/vmstat.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/vmstat.c b/mm/vmstat.c > index f534972f517de..7b93fbf9af092 100644 > --- a/mm/vmstat.c > +++ b/mm/vmstat.c > @@ -1568,7 +1568,7 @@ static void frag_show_print(struct seq_file *m, pg_data_t *pgdat, > static int frag_show(struct seq_file *m, void *arg) > { > pg_data_t *pgdat = (pg_data_t *)arg; > - walk_zones_in_node(m, pgdat, true, false, frag_show_print); > + walk_zones_in_node(m, pgdat, true, true, frag_show_print); > return 0; > } > > > base-commit: e43ffb69e0438cddd72aaa30898b4dc446f664f8 > -- > 2.34.1 >