From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 801F72F6164 for ; Mon, 24 Nov 2025 23:10:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764025846; cv=none; b=ja1qDuzLHwbhcqlhog2C491GbYgkSSCTYBB8G95XRp+FCnoa3w37iVngdzKuIMetkqKNjbhCbCZKU/0NkXqw7o6+eUjGQE1TGfklLaBsc5NJICKuy156QJcU4jhJJdCwWRCLl4NrhwZRh2XfynUlmT+dWRwT40tvhcPlLIcGq8M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764025846; c=relaxed/simple; bh=znbh610DMPhmbLhclKakniGAa7n7d8DTKuEp/zG6ZTM=; h=Date:To:From:Subject:Message-Id; b=q93I3xQSuRg6RHxOiu2GpKuDLNWk/408dP8YDq3rQaBlA0GpH6peKvRU0wVH+n3oB5z31Vz6YcDZ6IYe8BYJLx8p4VXXvj6AH8py3gEvBjr95QusuinpdmUl24NqaAcbz6oHmfXujHldFPpgH5MAWFqTbGU0210SvDwdOIByEKk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=UoadA5si; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="UoadA5si" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3797AC4CEF1; Mon, 24 Nov 2025 23:10:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1764025846; bh=znbh610DMPhmbLhclKakniGAa7n7d8DTKuEp/zG6ZTM=; h=Date:To:From:Subject:From; b=UoadA5siy7jSvlwLp1yUL4aMWnmRcXuwt4pR4hm5HtJ7WofFa9Hv5Z75pdoMW37h1 5crYmSZWap4t/XmspUDjykFHoXv9mXNzdc6uQDBcgznKw2sgHx5CG4fL6qwr5wMMZB qU7Szm3pOoc8xzwLV/o78FUe7cR+6b/8e/b9vTWQ= Date: Mon, 24 Nov 2025 15:10:45 -0800 To: mm-commits@vger.kernel.org,ywen.chen@foxmail.com,richardycc@google.com,minchan@google.com,bgeffon@google.com,senozhatsky@chromium.org,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] zram-drop-wb_limit_lock.patch removed from -mm tree Message-Id: <20251124231046.3797AC4CEF1@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: zram: drop wb_limit_lock has been removed from the -mm tree. Its filename was zram-drop-wb_limit_lock.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Sergey Senozhatsky Subject: zram: drop wb_limit_lock Date: Sat, 22 Nov 2025 16:40:27 +0900 We don't need wb_limit_lock. Writeback limit setters take an exclusive write zram init_lock, while wb_limit modifications happen only from a single task and under zram read init_lock. No concurrent wb_limit modifications are possible (we permit only one post-processing task at a time). Add lockdep assertions to wb_limit mutators. While at it, fixup coding styles. Link: https://lkml.kernel.org/r/20251122074029.3948921-5-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky Reviewed-by: Brian Geffon Cc: Minchan Kim Cc: Richard Chang Cc: Yuwen Chen Signed-off-by: Andrew Morton --- drivers/block/zram/zram_drv.c | 22 +++++----------------- drivers/block/zram/zram_drv.h | 1 - 2 files changed, 5 insertions(+), 18 deletions(-) --- a/drivers/block/zram/zram_drv.c~zram-drop-wb_limit_lock +++ a/drivers/block/zram/zram_drv.c @@ -532,9 +532,7 @@ static ssize_t writeback_limit_enable_st return ret; down_write(&zram->init_lock); - spin_lock(&zram->wb_limit_lock); zram->wb_limit_enable = val; - spin_unlock(&zram->wb_limit_lock); up_write(&zram->init_lock); ret = len; @@ -549,9 +547,7 @@ static ssize_t writeback_limit_enable_sh struct zram *zram = dev_to_zram(dev); down_read(&zram->init_lock); - spin_lock(&zram->wb_limit_lock); val = zram->wb_limit_enable; - spin_unlock(&zram->wb_limit_lock); up_read(&zram->init_lock); return sysfs_emit(buf, "%d\n", val); @@ -569,9 +565,7 @@ static ssize_t writeback_limit_store(str return ret; down_write(&zram->init_lock); - spin_lock(&zram->wb_limit_lock); zram->bd_wb_limit = val; - spin_unlock(&zram->wb_limit_lock); up_write(&zram->init_lock); ret = len; @@ -579,15 +573,13 @@ static ssize_t writeback_limit_store(str } static ssize_t writeback_limit_show(struct device *dev, - struct device_attribute *attr, char *buf) + struct device_attribute *attr, char *buf) { u64 val; struct zram *zram = dev_to_zram(dev); down_read(&zram->init_lock); - spin_lock(&zram->wb_limit_lock); val = zram->bd_wb_limit; - spin_unlock(&zram->wb_limit_lock); up_read(&zram->init_lock); return sysfs_emit(buf, "%llu\n", val); @@ -869,18 +861,18 @@ release_wb_ctl: static void zram_account_writeback_rollback(struct zram *zram) { - spin_lock(&zram->wb_limit_lock); + lockdep_assert_held_read(&zram->init_lock); + if (zram->wb_limit_enable) zram->bd_wb_limit += 1UL << (PAGE_SHIFT - 12); - spin_unlock(&zram->wb_limit_lock); } static void zram_account_writeback_submit(struct zram *zram) { - spin_lock(&zram->wb_limit_lock); + lockdep_assert_held_read(&zram->init_lock); + if (zram->wb_limit_enable && zram->bd_wb_limit > 0) zram->bd_wb_limit -= 1UL << (PAGE_SHIFT - 12); - spin_unlock(&zram->wb_limit_lock); } static int zram_writeback_complete(struct zram *zram, struct zram_wb_req *req) @@ -1005,13 +997,10 @@ static int zram_writeback_slots(struct z u32 index = 0; while ((pps = select_pp_slot(ctl))) { - spin_lock(&zram->wb_limit_lock); if (zram->wb_limit_enable && !zram->bd_wb_limit) { - spin_unlock(&zram->wb_limit_lock); ret = -EIO; break; } - spin_unlock(&zram->wb_limit_lock); while (!req) { req = zram_select_idle_req(wb_ctl); @@ -2962,7 +2951,6 @@ static int zram_add(void) init_rwsem(&zram->init_lock); #ifdef CONFIG_ZRAM_WRITEBACK zram->wb_batch_size = 32; - spin_lock_init(&zram->wb_limit_lock); #endif /* gendisk structure */ --- a/drivers/block/zram/zram_drv.h~zram-drop-wb_limit_lock +++ a/drivers/block/zram/zram_drv.h @@ -127,7 +127,6 @@ struct zram { bool claim; /* Protected by disk->open_mutex */ #ifdef CONFIG_ZRAM_WRITEBACK struct file *backing_dev; - spinlock_t wb_limit_lock; bool wb_limit_enable; u32 wb_batch_size; u64 bd_wb_limit; _ Patches currently in -mm which might be from senozhatsky@chromium.org are