From nobody Tue Dec 2 02:06:41 2025 Received: from mail-pj1-f47.google.com (mail-pj1-f47.google.com [209.85.216.47]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1A1BB36C0CE for ; Thu, 20 Nov 2025 15:22:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.47 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763652133; cv=none; b=ZvlKndIIWKe/y77op+y70qCmFjkrW81ncPF1Pagy9rRyjWJkq5uXAp08wNO/699myyBbKbOzSxTQUoKJ1zYox9uyH/zLei8g3aBWZQnojr1qBwnikhd0lzmT1UA4x8eeABkmxbg4uLshGMG7nSMtkXn3LpfaqLpR3IRnXp5LqoA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763652133; c=relaxed/simple; bh=QWWiZ4tHfeSo/6PGZPwYSUTo9cWJq/8Qx6JfMxUueJY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IThddJrovOXtBgfFds+W0H3heGZFiWpvioXyMieNzBdbB/8VeCYqF8eMLiqMaOH3eR6joJC3po4arQF4tdd+Mz0LZH0s+KCSzYBENRpPqDmP1w2Awu/ztji1nCzPARMKEI8Q82ADgHGzbMfvmnJ1EzCrKNyru3RWpAp6Sp6pecM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org; spf=pass smtp.mailfrom=chromium.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b=RWe0yvJM; arc=none smtp.client-ip=209.85.216.47 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chromium.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="RWe0yvJM" Received: by mail-pj1-f47.google.com with SMTP id 98e67ed59e1d1-34381ec9197so911614a91.1 for ; Thu, 20 Nov 2025 07:22:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1763652131; x=1764256931; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=ZAmKATgpNu/alXOGtuyOI3W/oFMTAwgOBJmF8/nzO6s=; b=RWe0yvJM4/Wq+vwCaQja9061Q+DPoK07YROLAfRCAjw19SO0s1SJ9U7WS8fBox8jQC lY4B3qu4qKVXAZuiF421G3ZE2RcDxWZTOrRw0d+vHIXtq2Zjoy4I8LGIDEO6oI+GA/TT jnxq8RkZYWscvyuC+SyZa3AeSFby59ALdTwXI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1763652131; x=1764256931; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=ZAmKATgpNu/alXOGtuyOI3W/oFMTAwgOBJmF8/nzO6s=; b=D9VuByll3UaKrJlcb8X+kcny/1fkk75ySmnn0fTtqWrThDFgzLHxRAAHIvF85K8SoY ZxPZ3UL/5nuwa39nncOGjP9ZcaxvE+m7AahOP0UFgZ77YFywWz0idtcOKktbWbBKECpe q9+QYzwIGJcrkf6VWJZAxOhtSEvS8Zp+bScrjyhJBkyphuIi4x+9BFTvH2CAuYNIRd1j Mf3peRn66VQONNlyhuxBBRpMXMAJBMkSAX/ereIIF5HaIc0Pjp53ZpPUZZjnAQt4DSOA uybbhrEjzhpaYIdTXKEshBwucKsBtTbgII0MD0aCNyDSNgrZWPBJlTQDtyb5d32OYEvR +4bA== X-Forwarded-Encrypted: i=1; AJvYcCVjPOd0S8BXdOpoJj6DGbNTdK4Nv9SUjluyniHh4iYegXk98XxoXoDBq88vdU4bQuH8sViW9Fj9yTbpOug=@vger.kernel.org X-Gm-Message-State: AOJu0YxCFXxBx6V3a/ezdfhDWyZmzv8O+WtqCyljIpHEfO1mLfaflk5L k4hTmjSnXehkj4qlc5XwqJDg57IeaYt5eEu0Mbh8Fd2eAINl6up1Hx72S13n33AKdA== X-Gm-Gg: ASbGncs3tp6IM6Mzwhn01CXNC1i33Vm44JKTy3WjXpwScQ1t1e1AsH1XnWANLHHAt3m MIbTvwV0qo7Z4uHeDNO8/aea5EVJQ+s6OqFM2HLR6zUdwc0Hvqcpp1WsPiK1rpaO5ki9n/azjUU GL549Ecizph5IQLW0ncyMcaKPr7A+cW9I5L7lOZSfCeu5gfhqZW6Q2ueftuMrLufWDHmwXX7ut0 B4dQ0T9zJKg31uoHzPjqdj/dCAhQiH5AumK9/XpNPgIjhOdoSO8KTjcytQ7kfxOOkvZl1BDMQPJ nvhIK8L5GfPQ2pY0xAOXWuM2svNgbeIvX9yVKWlsaB2tnEC8jxbOmv39vgGRfG58T0zrnrfSZs3 y1YmlcsljCWGsbra9mFEhlXkyapmAv3ROF21aZ7Br54kk5lBUngPnrMUUp7N31P6BeTxkGnDNK/ BCFB+7v7jJQV0bTd9f3q32yHAEV6pMpjVS7pFjBw== X-Google-Smtp-Source: AGHT+IGXx99ORaMc9c2Jm3Uyx2w4g0SNrUulESpO10c9NwCK4Ja79Nw8/lRM5g2x9jRJA1DHlD8CCA== X-Received: by 2002:a17:90b:53c8:b0:340:be44:dd0b with SMTP id 98e67ed59e1d1-34727d5233emr3818884a91.34.1763652131431; Thu, 20 Nov 2025 07:22:11 -0800 (PST) Received: from tigerii.tok.corp.google.com ([2401:fa00:8f:203:6762:7dba:8487:43a1]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-7c3f023f968sm3179642b3a.38.2025.11.20.07.22.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Nov 2025 07:22:11 -0800 (PST) From: Sergey Senozhatsky To: Andrew Morton , Minchan Kim , Yuwen Chen , Richard Chang Cc: Brian Geffon , Fengyu Lian , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org, Sergey Senozhatsky Subject: [RFC PATCHv5 2/6] zram: add writeback batch size device attr Date: Fri, 21 Nov 2025 00:21:22 +0900 Message-ID: <20251120152126.3126298-3-senozhatsky@chromium.org> X-Mailer: git-send-email 2.52.0.rc1.455.g30608eb744-goog In-Reply-To: <20251120152126.3126298-1-senozhatsky@chromium.org> References: <20251120152126.3126298-1-senozhatsky@chromium.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Introduce writeback_batch_size device attribute so that the maximum number of in-flight writeback bio requests can be configured at run-time per-device. This essentially enables batched bio writeback. Signed-off-by: Sergey Senozhatsky --- drivers/block/zram/zram_drv.c | 48 ++++++++++++++++++++++++++++++----- drivers/block/zram/zram_drv.h | 1 + 2 files changed, 43 insertions(+), 6 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 37c1416ac902..7904159e9226 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -588,6 +588,42 @@ static ssize_t writeback_limit_show(struct device *dev, return sysfs_emit(buf, "%llu\n", val); } =20 +static ssize_t writeback_batch_size_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct zram *zram =3D dev_to_zram(dev); + u32 val; + ssize_t ret =3D -EINVAL; + + if (kstrtouint(buf, 10, &val)) + return ret; + + if (!val) + val =3D 1; + + down_read(&zram->init_lock); + zram->wb_batch_size =3D val; + up_read(&zram->init_lock); + ret =3D len; + + return ret; +} + +static ssize_t writeback_batch_size_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + u32 val; + struct zram *zram =3D dev_to_zram(dev); + + down_read(&zram->init_lock); + val =3D zram->wb_batch_size; + up_read(&zram->init_lock); + + return sysfs_emit(buf, "%u\n", val); +} + static void reset_bdev(struct zram *zram) { if (!zram->backing_dev) @@ -779,10 +815,7 @@ static void release_wb_ctl(struct zram_wb_ctl *wb_ctl) kfree(wb_ctl); } =20 -/* XXX: should be a per-device sysfs attr */ -#define ZRAM_WB_REQ_CNT 32 - -static struct zram_wb_ctl *init_wb_ctl(void) +static struct zram_wb_ctl *init_wb_ctl(struct zram *zram) { struct zram_wb_ctl *wb_ctl; int i; @@ -797,7 +830,7 @@ static struct zram_wb_ctl *init_wb_ctl(void) init_waitqueue_head(&wb_ctl->done_wait); spin_lock_init(&wb_ctl->done_lock); =20 - for (i =3D 0; i < ZRAM_WB_REQ_CNT; i++) { + for (i =3D 0; i < zram->wb_batch_size; i++) { struct zram_wb_req *req; =20 /* @@ -1197,7 +1230,7 @@ static ssize_t writeback_store(struct device *dev, goto release_init_lock; } =20 - wb_ctl =3D init_wb_ctl(); + wb_ctl =3D init_wb_ctl(zram); if (!wb_ctl) { ret =3D -ENOMEM; goto release_init_lock; @@ -2840,6 +2873,7 @@ static DEVICE_ATTR_RW(backing_dev); static DEVICE_ATTR_WO(writeback); static DEVICE_ATTR_RW(writeback_limit); static DEVICE_ATTR_RW(writeback_limit_enable); +static DEVICE_ATTR_RW(writeback_batch_size); #endif #ifdef CONFIG_ZRAM_MULTI_COMP static DEVICE_ATTR_RW(recomp_algorithm); @@ -2861,6 +2895,7 @@ static struct attribute *zram_disk_attrs[] =3D { &dev_attr_writeback.attr, &dev_attr_writeback_limit.attr, &dev_attr_writeback_limit_enable.attr, + &dev_attr_writeback_batch_size.attr, #endif &dev_attr_io_stat.attr, &dev_attr_mm_stat.attr, @@ -2922,6 +2957,7 @@ static int zram_add(void) =20 init_rwsem(&zram->init_lock); #ifdef CONFIG_ZRAM_WRITEBACK + zram->wb_batch_size =3D 32; spin_lock_init(&zram->wb_limit_lock); #endif =20 diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index 6cee93f9c0d0..1a647f42c1a4 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -129,6 +129,7 @@ struct zram { struct file *backing_dev; spinlock_t wb_limit_lock; bool wb_limit_enable; + u32 wb_batch_size; u64 bd_wb_limit; struct block_device *bdev; unsigned long *bitmap; --=20 2.52.0.rc1.455.g30608eb744-goog