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Shuicheng Lin 985862be16
drm/xe/shrinker: Take a runtime PM ref before shrinking non-system memory
__xe_shrinker_walk() walks the SYSTEM and TT LRUs without a runtime PM
reference.  Shrinking a bo outside system memory invalidates its GPU
mappings, which needs the device resumed, so while it is runtime
suspended the page table zap trips an assert and the TLB invalidation
returns -ENODEV:

  WARNING: drivers/gpu/drm/xe/xe_bo.c:770 at xe_bo_move_notify+0x1fc/0x450 [xe]
   xe_bo_shrink+0x20f/0x2b0 [xe]
   __xe_shrinker_walk+0x174/0x410 [xe]
   xe_shrinker_scan+0x10c/0x1e0 [xe]
   do_shrink_slab+0x176/0x7e0
   drop_caches_sysctl_handler+0x9c/0xf0

Take a reference before walking a memory type other than XE_PL_SYSTEM
and stop there if it cannot be acquired.  Reuse the shrinker's existing
acquire path, which resumes the device directly where reclaim allows
that and otherwise queues the PM worker for a later scan.  Stop the walk
once the scan target is met, so a satisfied scan does not wake the
device.  System memory is still reclaimed while the device is suspended.

Gate this on xe_device_is_l2_flush_optimized(), the same condition under
which xe_bo_trigger_rebind() issues the invalidation for a non-fault-mode
vm, so reclaim is unaffected elsewhere.  The System CCS copy already has
its own reference in xe_bo_shrink().

Only a non-fault-mode vm can reach this, since a fault-mode vm requires
LR mode and that holds a runtime PM reference for the vm's lifetime.

Reproduced with igt@xe_madvise@dontneed-before-exec while the GPU is
runtime suspended.

v2: simplify needs_rpm check. (Matt)
    retarget Fixes tag since the issue occurs with the non-fault-mode
    path added by 4e7ebff69a.
v3: handle this in xe_shrinker.c instead of xe_bo.c (Thomas)
v4: stop the walk once the scan target is met. (Sashiko)
v5: rebase on the freed page accounting fix. (Sashiko)
v6: reuse the shrinker acquire path so runtime pm can be resumed
    directly instead of always queueing a worker. (Thomas)
v7: replace xe_pm_runtime_put() with xe_shrinker_runtime_pm_put(). (Thomas)

Fixes: 4e7ebff69a ("drm/xe/xe3p_lpg: flush shrinker bo cachelines manually")
Assisted-by: Claude:claude-opus-5
Cc: Tejas Upadhyay <tejas.upadhyay@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patch.msgid.link/20260909162102.1097006-3-shuicheng.lin@intel.com
Signed-off-by: Shuicheng Lin <shuicheng.lin@intel.com>
(cherry picked from commit 628f92b28bf4c371c10207daf6fc4caee0c0db2e)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2026-09-14 09:09:01 -04:00
arch Miscellaneous perf events fixes: 2026-09-13 08:44:54 -07:00
block block: save page offset gaps in cloned bio 2026-09-01 08:42:34 -06:00
certs treewide: fix indentation and whitespace in Kconfig files 2026-05-28 21:24:42 -07:00
crypto This push fixes a memory allocation overrun in crypto acomp. 2026-08-28 09:28:40 -07:00
Documentation Changes since last update: 2026-09-12 08:18:50 -07:00
drivers drm/xe/shrinker: Take a runtime PM ref before shrinking non-system memory 2026-09-14 09:09:01 -04:00
fs xfs: fixes for 7.3-rc3 2026-09-12 08:44:12 -07:00
include tracing fixes for 7.3: 2026-09-13 12:27:00 -07:00
init Bootconfig fixes for v7.3-rc3 2026-09-13 09:16:36 -07:00
io_uring io_uring-7.3-20260911 2026-09-11 12:36:13 -07:00
ipc mm.git review status for master..mm-nonmm-stable 2026-08-23 08:07:11 -07:00
kernel tracing fixes for 7.3: 2026-09-13 12:27:00 -07:00
lib block-7.3-20260911 2026-09-11 12:38:44 -07:00
LICENSES LICENSES: Add modern form of the LGPL-2.1 tags to the usage guide section 2025-10-22 07:58:19 +02:00
mm slab fixes for 7.3-rc2 2026-09-11 11:56:33 -07:00
net Nothing too exciting, usual stream of fixes. 2026-09-10 14:07:48 -07:00
rust Rust fixes for v7.3 (2nd) 2026-09-13 09:28:28 -07:00
samples rust: samples: add missing newlines in rust_print_main 2026-09-01 02:20:22 +02:00
scripts Fix misc objtool bugs: 2026-09-13 08:37:11 -07:00
security landlock: Test trace path output boundaries 2026-09-08 11:49:39 +02:00
sound sound fixes for 7.3-rc3 2026-09-11 10:00:07 -07:00
tools Bootconfig fixes for v7.3-rc3 2026-09-13 09:16:36 -07:00
usr usr: Correct a spelling by changing a letter 2026-08-05 14:51:58 +02:00
virt Arm: 2026-08-25 11:48:04 -07:00
.clang-format drm/bridge: rename drm_for_each_bridge_in_chain_scoped() to drm_for_each_bridge_in_chain() 2026-07-14 17:55:51 +02:00
.clippy.toml rust: bump Clippy's MSRV and clean incompatible_msrv allows 2026-04-07 09:51:39 +02:00
.cocciconfig
.editorconfig editorconfig: add rst extension 2026-01-26 19:07:09 -08:00
.get_maintainer.ignore .get_maintainer.ignore: add Nathan Chancellor 2026-08-03 21:10:12 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore SPDX patches for 7.2-rc1 2026-06-22 12:06:22 -07:00
.mailmap mailmap: update entry for Jens Axboe 2026-09-11 15:41:26 -07:00
.pylintrc docs: Move the python libraries to tools/lib/python 2025-11-18 09:22:40 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING
CREDITS Driver core fixes for 7.3-rc2 2026-09-05 11:59:05 -07:00
Kbuild checksyscalls: move instance functionality into generic code 2026-04-05 09:21:32 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS IOMMU fixes for Linux v7.3-rc3: 2026-09-12 07:55:52 -07:00
Makefile Linux 7.3-rc3 2026-09-13 14:38:02 -07:00
README README: remove out of place emdashes 2026-07-15 10:51:29 -06:00

Linux kernel
============

The Linux kernel is the core of any Linux operating system. It manages hardware,
system resources, and provides the fundamental services for all other software.

Quick Start
-----------

* Report a bug: See Documentation/admin-guide/reporting-issues.rst
* Get the latest kernel: https://kernel.org
* Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst
* Join the community: https://lore.kernel.org/

Essential Documentation
-----------------------

All users should be familiar with:

* Building requirements: Documentation/process/changes.rst
* Code of Conduct: Documentation/process/code-of-conduct.rst
* License: See COPYING

Documentation can be built with make htmldocs or viewed online at:
https://www.kernel.org/doc/html/latest/


Who Are You?
============

Find your role below:

* New Kernel Developer: Getting started with kernel development
* Academic Researcher: Studying kernel internals and architecture
* Security Expert: Hardening and vulnerability analysis
* Backport/Maintenance Engineer: Maintaining stable kernels
* System Administrator: Configuring and troubleshooting
* Maintainer: Leading subsystems and reviewing patches
* Hardware Vendor: Writing drivers for new hardware
* Distribution Maintainer: Packaging kernels for distros
* AI Coding Assistant: LLMs and AI-powered development tools


For Specific Users
==================

New Kernel Developer
--------------------

Welcome! Start your kernel development journey here:

* Getting Started: Documentation/process/development-process.rst
* Your First Patch: Documentation/process/submitting-patches.rst
* Coding Style: Documentation/process/coding-style.rst
* Build System: Documentation/kbuild/index.rst
* Development Tools: Documentation/dev-tools/index.rst
* Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst
* Core APIs: Documentation/core-api/index.rst

Academic Researcher
-------------------

Explore the kernel's architecture and internals:

* Researcher Guidelines: Documentation/process/researcher-guidelines.rst
* Memory Management: Documentation/mm/index.rst
* Scheduler: Documentation/scheduler/index.rst
* Networking Stack: Documentation/networking/index.rst
* Filesystems: Documentation/filesystems/index.rst
* RCU (Read-Copy Update): Documentation/RCU/index.rst
* Locking Primitives: Documentation/locking/index.rst
* Power Management: Documentation/power/index.rst

Security Expert
---------------

Security documentation and hardening guides:

* Security Documentation: Documentation/security/index.rst
* LSM Development: Documentation/security/lsm-development.rst
* Self Protection: Documentation/security/self-protection.rst
* Reporting Vulnerabilities: Documentation/process/security-bugs.rst
* CVE Procedures: Documentation/process/cve.rst
* Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst
* Security Features: Documentation/userspace-api/seccomp_filter.rst

Backport/Maintenance Engineer
-----------------------------

Maintain and stabilize kernel versions:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* Backporting Guide: Documentation/process/backporting.rst
* Applying Patches: Documentation/process/applying-patches.rst
* Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git for Maintainers: Documentation/maintainer/configure-git.rst

System Administrator
--------------------

Configure, tune, and troubleshoot Linux systems:

* Admin Guide: Documentation/admin-guide/index.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst
* Tracing/Debugging: Documentation/trace/index.rst
* Performance Security: Documentation/admin-guide/perf-security.rst
* Hardware Monitoring: Documentation/hwmon/index.rst

Maintainer
----------

Lead kernel subsystems and manage contributions:

* Maintainer Handbook: Documentation/maintainer/index.rst
* Pull Requests: Documentation/maintainer/pull-requests.rst
* Managing Patches: Documentation/maintainer/modifying-patches.rst
* Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst
* Development Process: Documentation/process/maintainer-handbooks.rst
* Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git Configuration: Documentation/maintainer/configure-git.rst

Hardware Vendor
---------------

Write drivers and support new hardware:

* Driver API Guide: Documentation/driver-api/index.rst
* Driver Model: Documentation/driver-api/driver-model/driver.rst
* Device Drivers: Documentation/driver-api/infrastructure.rst
* Bus Types: Documentation/driver-api/driver-model/bus.rst
* Device Tree Bindings: Documentation/devicetree/bindings/
* Power Management: Documentation/driver-api/pm/index.rst
* DMA API: Documentation/core-api/dma-api.rst

Distribution Maintainer
-----------------------

Package and distribute the kernel:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* ABI Documentation: Documentation/ABI/README
* Kernel Configuration: Documentation/kbuild/kconfig.rst
* Module Signing: Documentation/admin-guide/module-signing.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst

AI Coding Assistant
-------------------

CRITICAL: If you are an LLM or AI-powered coding assistant, you MUST read and
follow the AI coding assistants documentation before contributing to the Linux
kernel:

* Documentation/process/coding-assistants.rst

This documentation contains essential requirements about licensing, attribution,
and the Developer Certificate of Origin that all AI tools must comply with.


Communication and Support
=========================

* Mailing Lists: https://lore.kernel.org/
* IRC: #kernelnewbies on irc.oftc.net
* Bugzilla: https://bugzilla.kernel.org/
* MAINTAINERS file: Lists subsystem maintainers and mailing lists
* Email Clients: Documentation/process/email-clients.rst