From 64dd89ae01f2708a508e028c28b7906e4702a9a7 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Mon, 15 Dec 2025 12:57:53 -0500 Subject: mm/block/fs: remove laptop_mode Laptop mode was introduced to save battery, by delaying and consolidating writes and thereby maximize the time rotating hard drives wouldn't have to spin. Luckily, rotating hard drives, with their high spin-up times and power draw, are a thing of the past for battery-powered devices. Reclaim has also since changed to not write single filesystem pages anymore, and regular filesystem writeback is lumpy by design. The juice doesn't appear worth the squeeze anymore. The footprint of the feature is small, but nevertheless it's a complicating factor in mm, block, filesystems. Developers don't think about it, and it likely hasn't been tested with new reclaim and writeback changes in years. Let's sunset it. Keep the sysctl with a deprecation warning around for a few more cycles, but remove all functionality behind it. [akpm@linux-foundation.org: fix Documentation/admin-guide/laptops/index.rst] Link: https://lkml.kernel.org/r/20251216185201.GH905277@cmpxchg.org Signed-off-by: Johannes Weiner Suggested-by: Christoph Hellwig Reviewed-by: Christoph Hellwig Acked-by: Jens Axboe Reviewed-by: Shakeel Butt Acked-by: Michal Hocko Cc: Deepanshu Kartikey Signed-off-by: Andrew Morton --- include/linux/backing-dev-defs.h | 3 --- 1 file changed, 3 deletions(-) (limited to 'include/linux/backing-dev-defs.h') diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index 0217c1073735..c88fd4d37d1f 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -46,7 +46,6 @@ enum wb_reason { WB_REASON_VMSCAN, WB_REASON_SYNC, WB_REASON_PERIODIC, - WB_REASON_LAPTOP_TIMER, WB_REASON_FS_FREE_SPACE, /* * There is no bdi forker thread any more and works are done @@ -204,8 +203,6 @@ struct backing_dev_info { char dev_name[64]; struct device *owner; - struct timer_list laptop_mode_wb_timer; - #ifdef CONFIG_DEBUG_FS struct dentry *debug_dir; #endif -- cgit v1.2.3