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 6631EC433EF for ; Tue, 15 Mar 2022 17:22:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350516AbiCORXt (ORCPT ); Tue, 15 Mar 2022 13:23:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42968 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350484AbiCORXs (ORCPT ); Tue, 15 Mar 2022 13:23:48 -0400 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B41958807 for ; Tue, 15 Mar 2022 10:22:33 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-2d6994a6942so166049617b3.17 for ; Tue, 15 Mar 2022 10:22:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=zv11HNoiWOaRRTcqPWCnh8JAjyULAP9JPJTQwBFMsq8=; b=hdjiCLcdTxNnHZIaxKXevD6wYpO4tJh9hNr16sLmYoU8hjyEAcWwRvTquD+BH/awZT QLFX7uBm4fu+DPIzrGDgqlpefYngLQ9bEkwjiA0CLhYIE54t20c3UDQVZG4v0e099xN0 Ei/r3R+uge9e6P7mnUO82X+e+KhGuDYDONXf56eiWG2tLERvhGurNdZkkhUXVr+751RA PTsQ2W47lyNo8NTp5PPpg5sfys0Wth1CJll3ZWrO7pEp2rg5ZzqbPRGT7a6gC3QIDPGx pYpYVbH36L9vQLQVJd0qLcDMi3ZksltTqaFU/Kwa/U28pkNhamkT2z8IQ098seipUSE6 QzIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=zv11HNoiWOaRRTcqPWCnh8JAjyULAP9JPJTQwBFMsq8=; b=4gDer4HEwLoIDMLlkIFEXT135in5wMECqvkAxXhg73r3HmYBGwceE/7WXdafwk3RLB zHwtRlJJKF21jGCn6h6axOBjPaOMbamEi/5U2RaYF3wLQ0yqTlV1gBbj48NDjnth7HP0 oPg3aWvJadjmbDHma6EPk74lpRXuOHuC7zOqJ1YEI60Yra0git+ucVuuR98BF+5ezt7C c1EEDeMKJu3eR8a65NNTD3uOLL6QTfpnDVdfNpV6ckWttTt59DJtnieDPMKksHGm8ei+ oi3X7nLGw9GJ8JaZdRyoDknE74tWAsVyBANkoLUuOzpppU9/EsNyJ4qXQN1fte6LMMnO gnaA== X-Gm-Message-State: AOAM531EYJ23eC87tmZ8ODhv4Q8N8RQPPa7fMMaTWUBZ3J7EnLSk4bOH OLkAsu6pQiPtZ+9MTl+nIvVnU1wv65jr X-Google-Smtp-Source: ABdhPJywcoZma40GAuW6oHJQVBRIny/76kd1dbuidR6OYH4azzLPaSlrpAwem9MCflCBOgpSxDrnlhVoRxp+ X-Received: from bg.sfo.corp.google.com ([2620:15c:11a:202:213:25c1:7451:8743]) (user=bgeffon job=sendgmr) by 2002:a25:dd03:0:b0:633:3cd1:8f1d with SMTP id u3-20020a25dd03000000b006333cd18f1dmr10363049ybg.617.1647364952603; Tue, 15 Mar 2022 10:22:32 -0700 (PDT) Date: Tue, 15 Mar 2022 10:22:21 -0700 Message-Id: <20220315172221.9522-1-bgeffon@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.35.1.723.g4982287a31-goog Subject: [PATCH] zram: Add a huge_idle writeback mode From: Brian Geffon To: Andrew Morton Cc: Minchan Kim , Nitin Gupta , Sergey Senozhatsky , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-block@vger.kernel.org, Brian Geffon Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Today it's only possible to write back as a page, idle, or huge. A user might want to writeback pages which are huge and idle first as these idle pages do not require decompression and make a good first pass for writeback. Signed-off-by: Brian Geffon --- Documentation/admin-guide/blockdev/zram.rst | 6 ++++++ drivers/block/zram/zram_drv.c | 10 ++++++---- 2 files changed, 12 insertions(+), 4 deletions(-) diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/admin-guide/blockdev/zram.rst index 3e11926a4df9..af1123bfaf92 100644 --- a/Documentation/admin-guide/blockdev/zram.rst +++ b/Documentation/admin-guide/blockdev/zram.rst @@ -343,6 +343,12 @@ Admin can request writeback of those idle pages at right timing via:: With the command, zram writeback idle pages from memory to the storage. +Additionally, if a user choose to writeback only huge and idle pages +this can be accomplished with:: + + echo huge_idle > /sys/block/zramX/writeback + + If admin want to write a specific page in zram device to backing device, they could write a page index into the interface. diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index cb253d80d72b..f196902ae554 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -643,8 +643,8 @@ static int read_from_bdev_async(struct zram *zram, struct bio_vec *bvec, #define PAGE_WB_SIG "page_index=" #define PAGE_WRITEBACK 0 -#define HUGE_WRITEBACK 1 -#define IDLE_WRITEBACK 2 +#define HUGE_WRITEBACK (1<<0) +#define IDLE_WRITEBACK (1<<1) static ssize_t writeback_store(struct device *dev, @@ -664,6 +664,8 @@ static ssize_t writeback_store(struct device *dev, mode = IDLE_WRITEBACK; else if (sysfs_streq(buf, "huge")) mode = HUGE_WRITEBACK; + else if (sysfs_streq(buf, "huge_idle")) + mode = IDLE_WRITEBACK | HUGE_WRITEBACK; else { if (strncmp(buf, PAGE_WB_SIG, sizeof(PAGE_WB_SIG) - 1)) return -EINVAL; @@ -725,10 +727,10 @@ static ssize_t writeback_store(struct device *dev, zram_test_flag(zram, index, ZRAM_UNDER_WB)) goto next; - if (mode == IDLE_WRITEBACK && + if (mode & IDLE_WRITEBACK && !zram_test_flag(zram, index, ZRAM_IDLE)) goto next; - if (mode == HUGE_WRITEBACK && + if (mode & HUGE_WRITEBACK && !zram_test_flag(zram, index, ZRAM_HUGE)) goto next; /* -- 2.35.1.723.g4982287a31-goog