[PATCH AUTOSEL 6.15 6/8] PM: Restrict swap use to later in the suspend sequence

[Pavel Machek]

On Mon 2025-07-07 20:02:13, Sasha Levin wrote:
> From: Mario Limonciello <mario.limonciello at amd.com>
> 
> [ Upstream commit 12ffc3b1513ebc1f11ae77d053948504a94a68a6 ]
> 
> Currently swap is restricted before drivers have had a chance to do
> their prepare() PM callbacks. Restricting swap this early means that if
> a driver needs to evict some content from memory into sawp in it's
> prepare callback, it won't be able to.
> 
> On AMD dGPUs this can lead to failed suspends under memory pressure
> situations as all VRAM must be evicted to system memory or swap.
> 
> Move the swap restriction to right after all devices have had a chance
> to do the prepare() callback.  If there is any problem with the sequence,
> restore swap in the appropriate dpm resume callbacks or error handling
> paths.
> 
> Closes: https://github.com/ROCm/ROCK-Kernel-Driver/issues/174
> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/2362
> Signed-off-by: Mario Limonciello <mario.limonciello at amd.com>
> Tested-by: Nat Wittstock <nat at fardog.io>
> Tested-by: Lucian Langa <lucilanga at 7pot.org>
> Link: https://patch.msgid.link/20250613214413.4127087-1-superm1@kernel.org
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
> Signed-off-by: Sasha Levin <sashal at kernel.org>
> ---
> 
> **YES**
> 
> This commit should be backported to stable kernel trees for the
> following reasons:
> 
> ## Critical Bug Fix for Real User Issues
> 
> 1. **Fixes Actual Suspend Failures**: The commit addresses real-world
>    suspend failures under memory pressure on systems with AMD discrete
>    GPUs. The linked issues (ROCm/ROCK-Kernel-Driver#174 and
>    freedesktop.org/drm/amd#2362) indicate this affects actual users.
> 
> 2. **Regression Fix**: This is effectively a regression fix. The PM
>    subsystem's early swap restriction prevents AMD GPU drivers from
>    properly evicting VRAM during their prepare() callbacks, which is a
>    requirement that has become more critical as GPU VRAM sizes have
>    increased.

Stop copying AI generated nonsense to your emails while making it look
you wrote that. When did this regress?

								Pavel
-- 
I don't work for Nazis and criminals, and neither should you.
Boycott Putin, Trump, and Musk!
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