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 X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B58A4C04EB9 for ; Mon, 3 Dec 2018 05:50:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7551620851 for ; Mon, 3 Dec 2018 05:50:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ZQIl+PFe" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7551620851 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725851AbeLCFue (ORCPT ); Mon, 3 Dec 2018 00:50:34 -0500 Received: from mail-pl1-f196.google.com ([209.85.214.196]:43520 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725812AbeLCFue (ORCPT ); Mon, 3 Dec 2018 00:50:34 -0500 Received: by mail-pl1-f196.google.com with SMTP id gn14so5870380plb.10 for ; Sun, 02 Dec 2018 21:50:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=B2RVRe6PPqlKQOz6mb8WfwywxmFsbwDAKHNhWHhhKFg=; b=ZQIl+PFe9o6lpt6zfwl5p3/Soi6UILls1FrfmOsgkNu0n7Ol0IzPGmRUVwqpKFho+y MO5VGdoU2c0m7xGKxLhbLrodAcm3JtdCEDZh23oz9+mXZH2oX8I3ohQFWv/JBUeZ4zca iix0g0tIGsCmaO/OrFN1az+SHUhFaABPJRRiatXRsISHrE4CU32wVzEcNuemMy5eqYyt aQCiam3blP5x4aEt2oXLmDn7+K3lPh1qR1CcmS2AFL/3Yv06mLUpCZhnLTh+O7QF3zoa zxdDscylIPRaOHUvdnOcuoXimWkWlpAxIrwzU5o7/K/OuB4q38/BNyCEh2eo49PkhVXL 3mQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=B2RVRe6PPqlKQOz6mb8WfwywxmFsbwDAKHNhWHhhKFg=; b=BPHFdXf5fag1+btBm4k4x334bspbLEs8syacGGsyG1fY7qEC4TsF9GZxJh9p9CNbm5 aYmRASF8MmuQ+v3UmPyqqiYilrBHVGUzhK81s3TervtSoA8nVVtoFcD0aDCKsaEMfiZ/ 9HvWL9uejoo6NDtBvWbVMIDqpKenwxAxqWNG3ABTfogCRLazm3RlUydt94ACztusFwms //9xOKPK9yzdVEbdrvYkyDKqopxo811Vjr4nBloDKoV4j4mgA7FB8bcjl3hNeDyDSDIi IVeBaP6e6Ksxgttp2aELscy0h9gV2fD68Bfe1jfjEOWilwuacHa6UMBqsykRs8tzgyaT xkwQ== X-Gm-Message-State: AA+aEWYdVNq7M0vvRo17MqG9YhF5dkSZWbvKiNNTthNxVI2N1cIjxQup hIT1OWJSB5GJE1t6x7o6sDM= X-Google-Smtp-Source: AFSGD/WgXOyxH3FoeTt1W5YGVATv/5MGFs3pfIcaIuYEZEB+m2CIZGCnqPsUI2nKo3RX9ca1RB1NFA== X-Received: by 2002:a17:902:2867:: with SMTP id e94mr14831928plb.264.1543816230276; Sun, 02 Dec 2018 21:50:30 -0800 (PST) Received: from localhost ([175.223.22.143]) by smtp.gmail.com with ESMTPSA id f67sm17585647pfc.141.2018.12.02.21.50.28 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sun, 02 Dec 2018 21:50:29 -0800 (PST) Date: Mon, 3 Dec 2018 14:50:26 +0900 From: Sergey Senozhatsky To: Minchan Kim Cc: Andrew Morton , LKML , Sergey Senozhatsky , Joey Pabalinas Subject: Re: [PATCH v4 7/7] zram: writeback throttle Message-ID: <20181203055026.GD427@jagdpanzerIV> References: <20181203024045.153534-1-minchan@kernel.org> <20181203024045.153534-8-minchan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181203024045.153534-8-minchan@kernel.org> User-Agent: Mutt/1.11.0 (2018-11-25) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (12/03/18 11:40), Minchan Kim wrote: [..] > + down_read(&zram->init_lock); > + atomic64_set(&zram->stats.bd_wb_limit, val); > + if (val == 0) > + zram->stop_writeback = false; > + up_read(&zram->init_lock); [..] > + if (zram->stop_writeback) { > + ret = -EIO; > + break; > + } > + > if (!blk_idx) { > blk_idx = alloc_block_bdev(zram); > if (!blk_idx) { > @@ -694,6 +732,11 @@ static ssize_t writeback_store(struct device *dev, > zram_set_element(zram, index, blk_idx); > blk_idx = 0; > atomic64_inc(&zram->stats.pages_stored); > + if (atomic64_add_unless(&zram->stats.bd_wb_limit, > + -1 << (PAGE_SHIFT - 12), 0)) { > + if (atomic64_read(&zram->stats.bd_wb_limit) == 0) > + zram->stop_writeback = true; > + } Do we need ->stop_writeback? It should be identical to atomic64_read(&zram->stats.bd_wb_limit) == 0 Otherwise, looks good! -ss