Re: [PATCH] PM: suspend: select SUSPEND_SKIP_SYNC too if PM_USERSPACE_AUTOSLEEP is selected
From: "Rafael J. Wysocki" <rafael@kernel.org>
Date: 2022-08-24 13:11:22
Also in:
chrome-platform, linux-f2fs-devel, linux-fsdevel
On Wed, Aug 24, 2022 at 6:41 AM Juhyung Park [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Commit 2fd77fff4b44 ("PM / suspend: make sync() on suspend-to-RAM build-time optional") added an option to skip sync() on suspend entry to avoid heavy overhead on platforms with frequent suspends. Years later, commit 261e224d6a5c ("pm/sleep: Add PM_USERSPACE_AUTOSLEEP Kconfig") added a dedicated config for indicating that the kernel is subject to frequent suspends. While SUSPEND_SKIP_SYNC is also available as a knob that the userspace can configure, it makes sense to enable this by default if PM_USERSPACE_AUTOSLEEP is selected already. Signed-off-by: Juhyung Park <redacted> --- kernel/power/Kconfig | 1 + 1 file changed, 1 insertion(+)diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index 60a1d3051cc7..5725df6c573b 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig@@ -23,6 +23,7 @@ config SUSPEND_SKIP_SYNC bool "Skip kernel's sys_sync() on suspend to RAM/standby" depends on SUSPEND depends on EXPERT + default PM_USERSPACE_AUTOSLEEP
Why is this better than selecting SUSPEND_SKIP_SYNC from PM_USERSPACE_AUTOSLEEP?
help
Skip the kernel sys_sync() before freezing user processes.
Some systems prefer not to pay this cost on every invocation
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