From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f47.google.com (mail-ot1-f47.google.com [209.85.210.47]) (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 176FA44391; Wed, 15 May 2024 07:40:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.47 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715758861; cv=none; b=q8BTcAh8fJdXht7TmCsZfCR2SMC+PFb+aEqYWFS/mWIvIOmWmv19pvpGYUF73xuEOBAjsab9g96seZ5pbm0MHEG+Celd+B0h1sxDv2rCgH/YsPHW5OEBEan5QbUkZnzbyjWL5GEZW0M2gN7bdu+csuenAO4SSoJYpeXaIg9WsaM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715758861; c=relaxed/simple; bh=t9RspgqG+F2PVlmvWuEQ0GLhwwngFJ3ao73Evv6IOpc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=lycdBEhIjUgeahdFvxQWIdRdbrzKpTcR4FJwkqQH0/3i49ZR6WH5oXRcSutYRZdsNhVcRVWK81MCRz/Yi/vGBH91bL7PT8myyU+mH8ujy+Vqlyhbq8t9I+0Id9R8ENmWEs33yB2A4iBMgMspKyZIf9X4kWdt4wbbgZ4b3NefdwY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=e8+pZEkW; arc=none smtp.client-ip=209.85.210.47 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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="e8+pZEkW" Received: by mail-ot1-f47.google.com with SMTP id 46e09a7af769-6f0f5645c68so2211271a34.1; Wed, 15 May 2024 00:40:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1715758859; x=1716363659; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=TLhn4fqdh7o5svdDGhY37fd8hSl+dswnienDJA3jE4w=; b=e8+pZEkWRrmirjaxLS/JuS0I+LZprA9UzY2I1lgAHtV7JaJoWwp1sOvka8kN/b/V8B 0md3lEy3wv8jJHUH271MxrtdZTERZLp7vu/5Orfn7DiBzV6yRE3jkeYgIMYBArevzh86 eIiVlL4adsC6kpkQOr+f1mrjf11H+7gzCeLmZlCG1z3G6nbd9/bYO06telsZCFXj5Q+w A6AjussYuWZkGjket7wxkUd25Hcl92adqxxKtByIcaCsUgwgaMIB2LS+K89mIkjbt4mV fJ4yv871NzFE7phzB4UiNrvkCAOZ4PMIeHzlp6RVtIYswRoVvgQTE5kLtO9JBZrUcCa1 UMuQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1715758859; x=1716363659; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=TLhn4fqdh7o5svdDGhY37fd8hSl+dswnienDJA3jE4w=; b=OTY7I8PskVeO/rgBpDSwS4bdXjYizR6njNgpLfizv0ktga/OlOXODtn/cTLbqcf/Ew YTAqCFFY5UuLJVy0GNYR7uQDU2DKcAH6jomK6VRa/ddrpOGw68qFIFRTNpTbpkZkAnY4 B37fAwz0ODajWocgblRqLSD9sW9dwleMzswOhAO7e1GuAfEtG+/qLeP05QkWDuhC0pFK uVzN3zBSzNdpAKLXYSiWeH6SM/jY10rBRslRBy5Tp8ZojRcOvOuBz4Lo0F90QQOJhCG0 bPoAQfSlnVEMFBcD+SX7tAf7ee/+Wts6w2qv0WNcomcxYP1ncbqRX1pVdQdFp8z1jPJ5 q8bQ== X-Forwarded-Encrypted: i=1; AJvYcCWC6IOCdu5Mjah025IGxZ6SZkXkjDxAEkdheBZseQBSTw3dBq63G5HmQJhgHdEWsu0BvQ2DlZzsdPU+vz4rN82l/XqlZnxGrxXNjD2emHDeW/4ly55coq2dbM/lLBYsoX14enj69qCk418DOYfiRkW+wv/joXOwip59ZrEAeu6kVndH X-Gm-Message-State: AOJu0Yzpbgq6OpmkK5aowEtbWxaU7/G3PV7mFHzsYkvhg/lGjkJIkkpa Av/E9Qm1WDfiPBJW1w1o+F8XdaOfD4ufk8tG8t44zzcDuE+bnR6K X-Google-Smtp-Source: AGHT+IFAoB28Oxhj1Qe9IKvpyG7rsjUv6rTIqwphEgorIUy9cjMuH127glK9Bi63tCvYIjYKLEYIaQ== X-Received: by 2002:a05:6830:f8c:b0:6f1:23cc:b4ff with SMTP id 46e09a7af769-6f123ccbc9amr1247245a34.11.1715758859033; Wed, 15 May 2024 00:40:59 -0700 (PDT) Received: from localhost (dhcp-141-239-159-203.hawaiiantel.net. [141.239.159.203]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-63411530b0esm10843078a12.88.2024.05.15.00.40.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 May 2024 00:40:58 -0700 (PDT) Sender: Tejun Heo Date: Tue, 14 May 2024 21:40:56 -1000 From: Tejun Heo To: "zhaoyang.huang" Cc: Andrew Morton , Matthew Wilcox , Jens Axboe , Josef Bacik , Baolin Wang , linux-mm@kvack.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Zhaoyang Huang , steve.kang@unisoc.com Subject: Re: [RFC PATCH 2/2] mm: introduce budgt control in readahead Message-ID: References: <20240515012350.1166350-1-zhaoyang.huang@unisoc.com> <20240515012350.1166350-3-zhaoyang.huang@unisoc.com> Precedence: bulk X-Mailing-List: linux-block@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: <20240515012350.1166350-3-zhaoyang.huang@unisoc.com> Hello, On Wed, May 15, 2024 at 09:23:50AM +0800, zhaoyang.huang wrote: > +static unsigned long get_next_ra_size(struct readahead_control *ractl, > unsigned long max) > { > + unsigned long cur = ractl->ra->size; > + struct inode *inode = ractl->mapping->host; > + unsigned long budgt = inode->i_sb->s_bdev ? > + blk_throttle_budgt(inode->i_sb->s_bdev) : 0; Technical correctness aside, I'm not convinced it's generally a good idea to bubble up one specific IO control mechanism's detail all the way upto RA layer. Besides what's the gain here? For continuous IO stream, whether some RA bios are oversized or not shouldn't matter, no? Doesn't this just affect the accuracy of the last RA IO of a finite read stream? Thanks. -- tejun