From patchwork Tue Sep 21 18:51:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brian Geffon X-Patchwork-Id: 12508645 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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 5F39BC433F5 for ; Tue, 21 Sep 2021 18:51:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4786F611BD for ; Tue, 21 Sep 2021 18:51:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233369AbhIUSx0 (ORCPT ); Tue, 21 Sep 2021 14:53:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232614AbhIUSxZ (ORCPT ); Tue, 21 Sep 2021 14:53:25 -0400 Received: from mail-qk1-x749.google.com (mail-qk1-x749.google.com [IPv6:2607:f8b0:4864:20::749]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4CB7BC061575 for ; Tue, 21 Sep 2021 11:51:56 -0700 (PDT) Received: by mail-qk1-x749.google.com with SMTP id bl32-20020a05620a1aa000b004330d29d5bfso1058426qkb.23 for ; Tue, 21 Sep 2021 11:51:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=qxxb2w/M5fiqHKkhvOBDSrBf9iLSsSPoKQsdSta11bU=; b=Pd3yK4io43ZZA6XcTe6q1mRXI8C4EHFbBXhptEwxeD7sLqNdc5ugPi/3s/uBnW6UsV xfWUTffzb3iqfktMlPN3EBM1U0JftxjarIQ0EsXK50Jo5aYJHafX19nbP/ZlxrZ32yhH UaM4mqG/8cWuHTV/s3/cDuvQCclW5bBLfryWnjEyjnwJ7yow+SsI3h/ioquJC3rKN4Xm 2Nlv7rsNJAPo6OFcJmkHc/EaQDIPoDO5OXjk+8SBVbJdcA+HTajJEGgFm/3EJZLC3OYT JVl36dED6yfjs2pPQAsYtE9CHY4dHVuXXczwp6O/Io7KXyoOsdFZIl7d3SG725BX77Ia RsGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=qxxb2w/M5fiqHKkhvOBDSrBf9iLSsSPoKQsdSta11bU=; b=Cxx0pxXUbCgdlxa8jnLLH1SBqRe6QoZgMHwGA32bBhZ0Sd6zsccZEGdBb4mVpTjYY2 PVvvdbwHcM0RoMh1luSKxHj0biBytVXxrBilLjUwoRwOfikuklS8ZGNEbF/cfn1BmvFV wVZoYQhUZv2m7KK6Z4K9FlG40BxTE7oVlZb7e6R+XBy8TakTc8y7t869M7tVuyhEcynt Mt6hUKXmV0q+j30aFj3YquN+zXdvvBV+feHT02FpQjXqFKFKt9fMXo1IssqCkU6Ndtyo CEU3mx/fsW3k0Ppni8CaPXx2tm7BDT+SifDpgoJrULO8Dj94N3JqmJfSFEBMu5bL0u4X 5RkA== X-Gm-Message-State: AOAM533ODbHwGWz+RinyLGQEXPpvqVFcbXkLepYvtX3qF4n6GDKoOX1y cQyfMAEn3PkLi3TWjfG4rw7oCG+1mTLz X-Google-Smtp-Source: ABdhPJzr3+VvuTdtJ1ZDwvCQh+Off/E60wCu6siZEv/DiSq5zaz12wVOQzpBZRuYj9BDpZpr0TnljeMtnRmr X-Received: from bg.sfo.corp.google.com ([2620:15c:11a:202:4ba8:c770:5378:a8b7]) (user=bgeffon job=sendgmr) by 2002:a0c:e102:: with SMTP id w2mr32739256qvk.44.1632250315291; Tue, 21 Sep 2021 11:51:55 -0700 (PDT) Date: Tue, 21 Sep 2021 11:51:30 -0700 In-Reply-To: <20210917210640.214211-1-bgeffon@google.com> Message-Id: <20210921185130.944058-1-bgeffon@google.com> Mime-Version: 1.0 References: <20210917210640.214211-1-bgeffon@google.com> X-Mailer: git-send-email 2.33.0.464.g1972c5931b-goog Subject: [PATCH v2] zram: Introduce an aged idle interface From: Brian Geffon To: Andrew Morton Cc: Minchan Kim , Nitin Gupta , Sergey Senozhatsky , Jonathan Corbet , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-block@vger.kernel.org, Suleiman Souhlal , Jesse Barnes , Brian Geffon Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org This change introduces an aged idle interface to the existing idle sysfs file for zram. When CONFIG_ZRAM_MEMORY_TRACKING is enabled the idle file now also accepts an integer argument. This integer is the age (in seconds) of pages to mark as idle. The idle file still supports 'all' as it always has. This new approach allows for much more control over which pages get marked as idle. Signed-off-by: Brian Geffon --- Documentation/admin-guide/blockdev/zram.rst | 8 +++ drivers/block/zram/zram_drv.c | 60 +++++++++++++++------ 2 files changed, 52 insertions(+), 16 deletions(-) diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/admin-guide/blockdev/zram.rst index 700329d25f57..8c8a92e5c00c 100644 --- a/Documentation/admin-guide/blockdev/zram.rst +++ b/Documentation/admin-guide/blockdev/zram.rst @@ -328,6 +328,14 @@ as idle:: From now on, any pages on zram are idle pages. The idle mark will be removed until someone requests access of the block. IOW, unless there is access request, those pages are still idle pages. +Additionally, when CONFIG_ZRAM_MEMORY_TRACKING is enabled pages can be +marked as idle based on how long (in seconds) it's been since they were +last accessed, in seconds:: + + echo 86400 > /sys/block/zramX/idle + +In this example all pages which haven't been accessed in more than 86400 +seconds (one day) will be marked idle. Admin can request writeback of those idle pages at right timing via:: diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index fcaf2750f68f..1d1472fe4094 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -291,22 +291,16 @@ static ssize_t mem_used_max_store(struct device *dev, return len; } -static ssize_t idle_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) +/* + * Mark all pages which are older than or equal to cutoff as IDLE. + * Callers should hold the zram init lock in read mode + **/ +static void mark_idle(struct zram *zram, ktime_t cutoff) { - struct zram *zram = dev_to_zram(dev); + int is_idle = 1; unsigned long nr_pages = zram->disksize >> PAGE_SHIFT; int index; - if (!sysfs_streq(buf, "all")) - return -EINVAL; - - down_read(&zram->init_lock); - if (!init_done(zram)) { - up_read(&zram->init_lock); - return -EINVAL; - } - for (index = 0; index < nr_pages; index++) { /* * Do not mark ZRAM_UNDER_WB slot as ZRAM_IDLE to close race. @@ -314,14 +308,48 @@ static ssize_t idle_store(struct device *dev, */ zram_slot_lock(zram, index); if (zram_allocated(zram, index) && - !zram_test_flag(zram, index, ZRAM_UNDER_WB)) - zram_set_flag(zram, index, ZRAM_IDLE); + !zram_test_flag(zram, index, ZRAM_UNDER_WB)) { +#ifdef CONFIG_ZRAM_MEMORY_TRACKING + is_idle = (!cutoff || ktime_after(cutoff, zram->table[index].ac_time)); +#endif + if (is_idle) + zram_set_flag(zram, index, ZRAM_IDLE); + } zram_slot_unlock(zram, index); } +} - up_read(&zram->init_lock); +static ssize_t idle_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + struct zram *zram = dev_to_zram(dev); + u64 age_sec; + ktime_t cutoff_time = 0; + ssize_t rv = -EINVAL; - return len; + if (!sysfs_streq(buf, "all")) { +#ifdef CONFIG_ZRAM_MEMORY_TRACKING + /* If it did not parse as 'all' try to treat it as an integer */ + if (!kstrtoull(buf, 10, &age_sec)) + cutoff_time = ktime_sub(ktime_get_boottime(), + ns_to_ktime(age_sec * NSEC_PER_SEC)); + else +#endif + goto out; + } + + down_read(&zram->init_lock); + if (!init_done(zram)) + goto out_unlock; + + /* A age_sec of 0 marks everything as idle, this is the "all" behavior */ + mark_idle(zram, cutoff_time); + rv = len; + +out_unlock: + up_read(&zram->init_lock); +out: + return rv; } #ifdef CONFIG_ZRAM_WRITEBACK