From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ua1-f42.google.com (mail-ua1-f42.google.com [209.85.222.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 74B121D5178 for ; Thu, 10 Apr 2025 22:00:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.42 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744322413; cv=none; b=DkIxcf3DvCQHxnnfbXymSmnzlKj7ddUxFpAQtBjjVYqI3R4c6ZWWe4eMI9Pniu7AJg8aeyMi9/SqAX7g+r9tFo5zcHPj2JhcZFAWLVLeRzx9Y7q8fDaO4+gvWP2Q8koQYHKK5fzB2UWNSetLit4FrmuJy7rzZs4WEkeC7glpSB8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744322413; c=relaxed/simple; bh=cqGtxI1BGnfmMlhZLW6kkWvhxcjVhEDts7Pr3YT2wPc=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=padkMiumlJloNZbIsBEKzrJNKwDiGtMsrlbXi/OU4YaJLleBPseiidJWOkiraw0yAYmRPniYXJkt4IjphPZBWmwWCIWE/ydFu8KBKr1OLzcRZAMfzkZx9Jq+r2bfAUj61suLHZLEbzGJ3JXtt5ROYbSJUgwVRhLAolFV9iWiZsE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=KshUvv/1; arc=none smtp.client-ip=209.85.222.42 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="KshUvv/1" Received: by mail-ua1-f42.google.com with SMTP id a1e0cc1a2514c-86d5a786c7cso580845241.2 for ; Thu, 10 Apr 2025 15:00:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1744322410; x=1744927210; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=NzFUOXA2PlVpOukaGWjpW+Vwcf9Cq5O5NSrTad1d5OU=; b=KshUvv/1csZXSqYfuO8JR5rqtOXUMi+Gj2Fc4upz57jrn+svWyjMpWQ8Pdcl51KAaM z1ozTnUM9k+klaiI95JY4xIOF18pk/S1LKtdfX7aI8J51jCb30Uu6jPVSd6wqGk62Mil cekNkTZWVzVUz0g9W+Vzn3/XUS+lAXEapP05DdpZMlbLi8dgSOxG7O+kBomrTZ14CS1c gs7ZtY8GUUn3W2BHNPPcwB8bEQ1KXQiPpjoaZlfvM7po/wC1kdw2/y3nlwcemmwsxFx4 OVt8s3g3oM9f1SdxSVi0Ku9Wn0EgYLXazMu+fs1WpMX+ThhHs7FFoRKxQA9s07Lw3mWS f+CQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1744322410; x=1744927210; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=NzFUOXA2PlVpOukaGWjpW+Vwcf9Cq5O5NSrTad1d5OU=; b=Unx/LSfJwmvrMbaYrUyIyXwevRjMiQ7k8oEzckmwf1RNVVJE1eWTXDhQCh2IRB/SDZ 1yPQJ/ZXPu1RpUm8FzNYd7LHiOM7TiRCSaHIr83szzOjcZiyABp6OhYafiZ/b2vH3clW 7Z+61lru3DSiPGVPhIK622VpuvsFZU6fikhg1twK/EmWQbUCX1XwtwzcU5VcbDFWs4yA NneIMPJYoGPCcsQdHVFZXMqjquQoi5PKJdi8G9dNgETsRFGc+Bk6Pz3HR1MiHptsOxG+ wOpX4efd2FBG4wodGP/pT9YCb17cb2AYpNaiUbHhLaI6JPQLoZ8g2oRwSmnmNE1Ma9xV AoqQ== X-Forwarded-Encrypted: i=1; AJvYcCV2wM5xqpiuv6nELVjD7oIiloPMZMInTama8CqMznlrxs2AEtwu9WyNXa9Egu4ash+RyKgst32WtujuJWs=@vger.kernel.org X-Gm-Message-State: AOJu0YxU3nkvgA4b5yfvAo6ky+AyJCktnsGQF40zdroYcKT0xVFqQtmX 7lWQpBxVX/ERY8+fzGYIbxSGlQ0ZdkzNSJGoK8vhDNOP25wj6hxSyCSzkZasHNvz3/yfiXdyqFR QuIr7hDja3G36qOm5mgUi9h5nWLUw1jMc3Ys= X-Gm-Gg: ASbGncsvLrGdjLzU/TNfszKXkwSThODPj6/gONUHFBjvoogH6Ioq30S/qNU9eC87Mtj WMYVCOIh5w3Z0ZxRXqpuNohDU0YldWfPozb7IIDNMlTi7NWxVVolSdQpBEiljJ2hjkxnkBcU1bP EkeWVY65fndbyNemVczQlwL6UDqeGvxiad X-Google-Smtp-Source: AGHT+IG1mDFRL8aYmm3d+t6l4YqCBQXEG7Iw89dS6jPTFRXPvNQYKWR8XwxBSPXKGx5bvg91dWVEnJzOAmoomFLTT80= X-Received: by 2002:a05:6102:dce:b0:4c3:7f7:92f4 with SMTP id ada2fe7eead31-4c9e4ee6b5amr162309137.6.1744322410276; Thu, 10 Apr 2025 15:00:10 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <2d42decac5194c2c8d897b0424f0dcf3@honor.com> In-Reply-To: From: Barry Song <21cnbao@gmail.com> Date: Fri, 11 Apr 2025 09:59:57 +1200 X-Gm-Features: ATxdqUHyAA6zq9M3v3P8tWmqRklK_8tZvzqB3nsGrqvZdL5RqHyESZYjn0IWJ2A Message-ID: Subject: Re: [PATCH] mm: simplify zone_idx() To: Mike Rapoport Cc: gaoxu , Andrew Morton , "surenb@google.com" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , yipengxiang Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, Apr 11, 2025 at 2:42=E2=80=AFAM Mike Rapoport wro= te: > > Hi, > > On Thu, Apr 10, 2025 at 12:03:00PM +0000, gaoxu wrote: > > store zone_idx directly in struct zone to simplify and optimize zone_id= x() > > Do you see an actual speed up somewhere? +1. Curious if there's data indicating zone_idx is a hot path. > > > Signed-off-by: gao xu > > --- > > include/linux/mmzone.h | 3 ++- > > mm/mm_init.c | 1 + > > 2 files changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > > index 4c95fcc9e..7b14f577d 100644 > > --- a/include/linux/mmzone.h > > +++ b/include/linux/mmzone.h > > @@ -941,6 +941,7 @@ struct zone { > > #endif > > > > const char *name; > > + enum zone_type zone_idx; > > > > #ifdef CONFIG_MEMORY_ISOLATION > > /* > > @@ -1536,7 +1537,7 @@ static inline int local_memory_node(int node_id) = { return node_id; }; > > /* > > * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL z= one, etc. > > */ > > -#define zone_idx(zone) ((zone) - (zone)->zone_pgdat->nod= e_zones) > > +#define zone_idx(zone) ((zone)->zone_idx) > > > > #ifdef CONFIG_ZONE_DEVICE > > static inline bool zone_is_zone_device(struct zone *zone) > > diff --git a/mm/mm_init.c b/mm/mm_init.c > > index 9659689b8..a7f7264f1 100644 > > --- a/mm/mm_init.c > > +++ b/mm/mm_init.c > > @@ -1425,6 +1425,7 @@ static void __meminit zone_init_internals(struct = zone *zone, enum zone_type idx, > > atomic_long_set(&zone->managed_pages, remaining_pages); > > zone_set_nid(zone, nid); > > zone->name =3D zone_names[idx]; > > + zone->zone_idx =3D idx; > > zone->zone_pgdat =3D NODE_DATA(nid); > > spin_lock_init(&zone->lock); > > zone_seqlock_init(zone); > > -- > > 2.17.1 > > -- > Sincerely yours, > Mike. Thanks Barry