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 6CECA36F420 for ; Mon, 8 Jun 2026 08:17:08 +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=1780906629; cv=none; b=AhL7asPj65pUOoQJ/zSSaU5QGPQ65Otxo311macaowI6hdDVsYDQE5DlAm6dtxpjIssOBJJtQgc0HOxctXjx67vmI2nJtR1jxnyxEuKz6e9gdsFAoPKWLXozPSmKGyCOVH1tQVpfRSbP4KIRLdo/9RAsGN3ghLRKEs8dWffHayw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780906629; c=relaxed/simple; bh=jHbezuq10LbEJ2jd2Sf1hmmnaWqqYmSapyL6PrGle0c=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Pa2ss6utjtUtPtX7UNlmYEz/U+RUy3GUCsbb4hbMMp9qgGZo++RPQhmH6z7c2yrvOUQ0FhSOK/krGPxVL/YC3wINbhmEFVuJED4KS9Wk251SCL5VVdvGfg1CCfISxVfNXrfZmPIOmRdRxQkf2GHHWgrNIk0ouriDERPpV2j37dw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OEWBxu5K; 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="OEWBxu5K" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 973671F00893; Mon, 8 Jun 2026 08:17:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780906628; bh=2CGzJHMR082CZEaBJvYYklEx/AUabVfo33DoJiswTsg=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=OEWBxu5KnEguBwQsJmXEOlLVlzd41WaccgHCS8VR/HX3KoqArK5AD3XyC4v/449Rw h4QokdvZhHHmCVVCXc1m12gHafV1segbzIfA8uFZKOjsWfIHlf8H6w2Xjd6HPlD+AF /4+OJEnpyV1GKW2Di/dSvT6HvNQrPdUwHpPzLfi0hik9/0VRnBU0/s8XkFkfu8by20 sQiCyOtUtmP0znCP62oXgEI4eEQLRsOwVNv2yNi3bWFZTys6z56zW5JhOYXOep6QrT CPvnTTDNz38OyCIF5AFykhFHD2yabhfoFfW4Tmg7oEZRK1RBBIaUzDU54/eXJV/VcC lwlYJJazkHi/Q== Date: Mon, 8 Jun 2026 09:17:02 +0100 From: Lorenzo Stoakes To: Imran Khan Cc: akpm@linux-foundation.org, 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> 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 LGTM, so: Reviewed-by: Lorenzo Stoakes > --- > 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 > Cheers, Lorenzo