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[23.128.96.18]) by mx.google.com with ESMTP id q19si252258eja.435.2021.09.21.15.08.45; Tue, 21 Sep 2021 15:09:09 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=l0xqSrhq; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232590AbhIUTpW (ORCPT + 99 others); Tue, 21 Sep 2021 15:45:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233197AbhIUTpV (ORCPT ); Tue, 21 Sep 2021 15:45:21 -0400 Received: from mail-qk1-x74a.google.com (mail-qk1-x74a.google.com [IPv6:2607:f8b0:4864:20::74a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 68C98C061756 for ; Tue, 21 Sep 2021 12:43:52 -0700 (PDT) Received: by mail-qk1-x74a.google.com with SMTP id h7-20020a37b707000000b003fa4d25d9d0so2113912qkf.17 for ; Tue, 21 Sep 2021 12:43:52 -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=2Nm1E5fYqM+jWf7/uwd5uL7JDVTYKQ4yOjBmP2vLC7A=; b=l0xqSrhqSkKXdp/rvmYs8zyIR70QOI6I5dr8fZW0m08B3GQjc1LkUj5ugdeRsW4OnA ud3rmYa8VLKBZsmz7EYPviKVZUVPLt+p8NcyFq8096f32Kl/GWrtuyjuijc+k/PuVieR bg1RZQB0vwjGqy4iN37tJff2FKPu/ID2aGLBe/v07/HRIsvdzA1+VbEDzMJP91iI+ukH /ngZF4wqqpmp8ngWZbB3+0MvD5gS4qADo8ptyO2/sE/78WUKPaT5Slew/p38J+pSiapN d5bDowJfR2NspIiCl626IGQocuEfzcsGy/vUh3nQOGjWBSFi5kN5n6zLBH4NMdr5r7XI fvpg== 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=2Nm1E5fYqM+jWf7/uwd5uL7JDVTYKQ4yOjBmP2vLC7A=; b=GLw2qycDoX0hWmxmGFw+YgICIllNabokH60jdIBxXL8OWFBoCyzQ8JZ1E3rl//8Oke ZT0zobyZIKN27rJW3VaFUdR/sHm9wv9gUCcqV+Ym/s5iGtG/RehL9fdWBsYl1LJc+oOc RNGbCBTQLW11Xp95PeBrYNREYNnfNSnbyzcWQcEG80/5phVQW0cchwCfqxujVBG6VmCK cg5emuAFmQwPoU3fUrZ7jgqw9aVc44+bd1T44H1LSoKORtwGiOGEM4jVIkT8NJ2UVhmZ TEMXIEJtg9t+eTwalbClBsI5Qa0uAp9uw+30p7E8hr3rX4he3qyPCTCsXvMqKA1Q4xZd 9U+Q== X-Gm-Message-State: AOAM530JjKCBkTnotyA6qJ+AR+LBD/8VXn7Le1+6wrUqAGJg5IRr4gBa L8h2OdaQodJi6oDTIbxdVfV3wBdv4wj3 X-Received: from bg.sfo.corp.google.com ([2620:15c:11a:202:4ba8:c770:5378:a8b7]) (user=bgeffon job=sendgmr) by 2002:a05:6214:1425:: with SMTP id o5mr32729818qvx.5.1632253431404; Tue, 21 Sep 2021 12:43:51 -0700 (PDT) Date: Tue, 21 Sep 2021 12:43:36 -0700 In-Reply-To: <20210917210640.214211-1-bgeffon@google.com> Message-Id: <20210921194336.947226-1-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 v3] 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 Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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. v2 -> v3: - Correct unused variable warning when CONFIG_ZRAM_MEMORY_TRACKING is not enabled. v1 -> v2: - Switch to using existing idle file. - Dont compare ktime directly. 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..2af5cdb8da1a 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); + ktime_t cutoff_time = 0; + ssize_t rv = -EINVAL; - return len; + if (!sysfs_streq(buf, "all")) { +#ifdef CONFIG_ZRAM_MEMORY_TRACKING + u64 age_sec; + /* 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 -- 2.33.0.464.g1972c5931b-goog