From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 DCC5E6465 for ; Tue, 22 Mar 2022 21:47:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A67DCC340F2; Tue, 22 Mar 2022 21:47:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1647985639; bh=CM1n9mzzhlL7za/LeGoqlxU72kT0yRPY/3c8VjkAdpw=; h=Date:To:From:In-Reply-To:Subject:From; b=NcQ7n2NFi96gYLMps5hb3/IiVGnhOXfQgX77FnwXfR4FrBaS0KWepr+YRsiIW14fo kZAd9Qzqc/CzXiQtRte5j9yuXADOLjQQ4FLncXLqTbYpWSpG0/tGTYWAPLmz28hsMD RdUlZIBUc4z8SiV6CIWZuLr/pqjvTLLEmHzE+Tjk= Date: Tue, 22 Mar 2022 14:47:19 -0700 To: osalvador@suse.de,david@redhat.com,linmiaohe@huawei.com,akpm@linux-foundation.org,patches@lists.linux.dev,linux-mm@kvack.org,mm-commits@vger.kernel.org,torvalds@linux-foundation.org,akpm@linux-foundation.org From: Andrew Morton In-Reply-To: <20220322143803.04a5e59a07e48284f196a2f9@linux-foundation.org> Subject: [patch 173/227] mm/memory_hotplug: avoid calling zone_intersects() for ZONE_NORMAL Message-Id: <20220322214719.A67DCC340F2@smtp.kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: From: Miaohe Lin Subject: mm/memory_hotplug: avoid calling zone_intersects() for ZONE_NORMAL If zid reaches ZONE_NORMAL, the caller will always get the NORMAL zone no matter what zone_intersects() returns. So we can save some possible cpu cycles by avoid calling zone_intersects() for ZONE_NORMAL. Link: https://lkml.kernel.org/r/20220207133643.23427-3-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Reviewed-by: David Hildenbrand Reviewed-by: Oscar Salvador Signed-off-by: Andrew Morton --- mm/memory_hotplug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/memory_hotplug.c~mm-memory_hotplug-avoid-calling-zone_intersects-for-zone_normal +++ a/mm/memory_hotplug.c @@ -823,7 +823,7 @@ static struct zone *default_kernel_zone_ struct pglist_data *pgdat = NODE_DATA(nid); int zid; - for (zid = 0; zid <= ZONE_NORMAL; zid++) { + for (zid = 0; zid < ZONE_NORMAL; zid++) { struct zone *zone = &pgdat->node_zones[zid]; if (zone_intersects(zone, start_pfn, nr_pages)) _