From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4780C4332F for ; Thu, 19 May 2022 08:54:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235677AbiESIyQ (ORCPT ); Thu, 19 May 2022 04:54:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34434 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231418AbiESIyO (ORCPT ); Thu, 19 May 2022 04:54:14 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CB4BB9CF5C; Thu, 19 May 2022 01:54:13 -0700 (PDT) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 87D632190C; Thu, 19 May 2022 08:54:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1652950452; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Fcqmrpxaer0Q0d9KKEW1aRv2ycWgGPdWyzaSn+WUbBk=; b=MCqflNXNG3ngH2MmJW00KgKiExOrIVLN0FjbU1tW/EjTGsQoOt4VFLU44GX9dgv4k0vDWj oiGvElYDh1fZtGPXkj4GrjWCc4A2LzW2xS7tI5XSE5jLbx9+Qaj+1ajb/FG1EX2xEp6VHy /TTH4BL7tSch0QManLpc1RCH/PFlWkY= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1652950452; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Fcqmrpxaer0Q0d9KKEW1aRv2ycWgGPdWyzaSn+WUbBk=; b=CSE0dPEFDF1WBQ1nOUVh0VvJ3pzuB+V0rQ9k1XNYeePdsxTD4zd1GicWO9Gw9VSL9LgghM lUuBj/2cI6p+HwBg== Received: from quack3.suse.cz (unknown [10.100.224.230]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 76B932C143; Thu, 19 May 2022 08:54:12 +0000 (UTC) Received: by quack3.suse.cz (Postfix, from userid 1000) id 17A81A062F; Thu, 19 May 2022 10:54:12 +0200 (CEST) Date: Thu, 19 May 2022 10:54:12 +0200 From: Jan Kara To: Christoph Hellwig Cc: Stefan Roesch , io-uring@vger.kernel.org, kernel-team@fb.com, linux-mm@kvack.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, david@fromorbit.com, jack@suse.cz Subject: Re: [RFC PATCH v3 15/18] mm: Add balance_dirty_pages_ratelimited_async() function Message-ID: <20220519085412.ngnnhsf6iy35vqn3@quack3.lan> References: <20220518233709.1937634-1-shr@fb.com> <20220518233709.1937634-16-shr@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Thu 19-05-22 01:29:21, Christoph Hellwig wrote: > > +static int balance_dirty_pages_ratelimited_flags(struct address_space *mapping, > > + bool no_wait) > > { > > This doesn't actully take flags, but a single boolean argument. So > either it needs a new name, or we actually pass a descriptiv flag. > > > +/** > > + * balance_dirty_pages_ratelimited_async - balance dirty memory state > > + * @mapping: address_space which was dirtied > > + * > > + * Processes which are dirtying memory should call in here once for each page > > + * which was newly dirtied. The function will periodically check the system's > > + * dirty state and will initiate writeback if needed. > > + * > > + * Once we're over the dirty memory limit we decrease the ratelimiting > > + * by a lot, to prevent individual processes from overshooting the limit > > + * by (ratelimit_pages) each. > > + * > > + * This is the async version of the API. It only checks if it is required to > > + * balance dirty pages. In case it needs to balance dirty pages, it returns > > + * -EAGAIN. > > + */ > > +int balance_dirty_pages_ratelimited_async(struct address_space *mapping) > > +{ > > + return balance_dirty_pages_ratelimited_flags(mapping, true); > > +} > > +EXPORT_SYMBOL(balance_dirty_pages_ratelimited_async); > > I'd much rather export the underlying > balance_dirty_pages_ratelimited_flags helper than adding a pointless > wrapper here. And as long as only iomap is supported there is no need > to export it at all. This was actually my suggestion so I take the blame ;) I have suggested this because I don't like non-static functions with bool arguments (it is unnecessarily complicated to understand what the argument means or grep for it etc.). If you don't like the wrapper, creating int balance_dirty_pages_ratelimited_flags(struct address_space *mapping, unsigned int flags) and have something like: #define BDP_NOWAIT 0x0001 is fine with me as well. Honza -- Jan Kara SUSE Labs, CR