linux-toradex.git/tools/sched_ext/scx_show_state.py, branch v7.1 Linux kernel for Apalis and Colibri modules tools/sched_ext: Fix scx_show_state per-scheduler state reads 2026-05-27T19:12:38+00:00 Zicheng Qu quzicheng315@gmail.com 2026-05-27T09:38:50+00:00 b565a73baec275a3f4b49c1300ab396daf4a748e scx_show_state.py still reads scx_aborting and scx_bypass_depth as global symbols. Those symbols no longer exist after the state was moved into struct scx_sched, so the drgn script fails when it reaches either field. Read aborting and bypass_depth from scx_root instead. This preserves the script's current root-scheduler view: with sub-scheduler support, the reported values are for the root scheduler and sub-schedulers are not enumerated. Fixes: 5c8d98a1b4de ("sched_ext: Move bypass state into scx_sched") Fixes: c1743da43cf5 ("sched_ext: Move aborting flag to per-scheduler field") Signed-off-by: Zicheng Qu <quzicheng@huawei.com> Reviewed-by: Andrea Righi <arighi@nvidia.com> Signed-off-by: Tejun Heo <tj@kernel.org> 
scx_show_state.py still reads scx_aborting and scx_bypass_depth as
global symbols. Those symbols no longer exist after the state was moved
into struct scx_sched, so the drgn script fails when it reaches either
field.

Read aborting and bypass_depth from scx_root instead. This preserves the
script's current root-scheduler view: with sub-scheduler support, the
reported values are for the root scheduler and sub-schedulers are not
enumerated.

Fixes: 5c8d98a1b4de ("sched_ext: Move bypass state into scx_sched")
Fixes: c1743da43cf5 ("sched_ext: Move aborting flag to per-scheduler field")
Signed-off-by: Zicheng Qu <quzicheng@huawei.com>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
tools/sched_ext: update scx_show_state.py for scx_aborting change 2025-12-28T16:11:26+00:00 Kohei Enju enjuk@amazon.com 2025-12-26T08:46:50+00:00 c9894e6f0160414b57e895332c580cf5c8da6780 Commit a69040ed57f5 ("sched_ext: Simplify breather mechanism with scx_aborting flag") removed scx_in_softlockup and scx_breather_depth, replacing them with scx_aborting. Update the script accordingly. Fixes: a69040ed57f5 ("sched_ext: Simplify breather mechanism with scx_aborting flag") Signed-off-by: Kohei Enju <enjuk@amazon.com> Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com> Signed-off-by: Tejun Heo <tj@kernel.org> 
Commit a69040ed57f5 ("sched_ext: Simplify breather mechanism with
scx_aborting flag") removed scx_in_softlockup and scx_breather_depth,
replacing them with scx_aborting.

Update the script accordingly.

Fixes: a69040ed57f5 ("sched_ext: Simplify breather mechanism with scx_aborting flag")
Signed-off-by: Kohei Enju <enjuk@amazon.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
tools/sched_ext: fix scx_show_state.py for scx_root change 2025-12-28T16:11:13+00:00 Kohei Enju enjuk@amazon.com 2025-12-26T08:46:49+00:00 f92ff79ba2640fc482bf2bfb5b42e33957f90caf Commit 48e126777386 ("sched_ext: Introduce scx_sched") introduced scx_root and removed scx_ops, causing scx_show_state.py to fail when searching for the 'scx_ops' object. [1] Fix by using 'scx_root' instead, with NULL pointer handling. [1] # drgn -s vmlinux ./tools/sched_ext/scx_show_state.py Traceback (most recent call last): File "/root/.venv/bin/drgn", line 8, in <module> sys.exit(_main()) ~~~~~^^ File "/root/.venv/lib64/python3.14/site-packages/drgn/cli.py", line 625, in _main runpy.run_path( ~~~~~~~~~~~~~~^ script_path, init_globals={"prog": prog}, run_name="__main__" ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ) ^ File "<frozen runpy>", line 287, in run_path File "<frozen runpy>", line 98, in _run_module_code File "<frozen runpy>", line 88, in _run_code File "./tools/sched_ext/scx_show_state.py", line 30, in <module> ops = prog['scx_ops'] ~~~~^^^^^^^^^^^ _drgn.ObjectNotFoundError: could not find 'scx_ops' Fixes: 48e126777386 ("sched_ext: Introduce scx_sched") Signed-off-by: Kohei Enju <enjuk@amazon.com> Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com> Signed-off-by: Tejun Heo <tj@kernel.org> 
Commit 48e126777386 ("sched_ext: Introduce scx_sched") introduced
scx_root and removed scx_ops, causing scx_show_state.py to fail when
searching for the 'scx_ops' object. [1]

Fix by using 'scx_root' instead, with NULL pointer handling.

[1]
 # drgn -s vmlinux ./tools/sched_ext/scx_show_state.py
 Traceback (most recent call last):
   File "/root/.venv/bin/drgn", line 8, in <module>
     sys.exit(_main())
              ~~~~~^^
   File "/root/.venv/lib64/python3.14/site-packages/drgn/cli.py", line 625, in _main
     runpy.run_path(
     ~~~~~~~~~~~~~~^
         script_path, init_globals={"prog": prog}, run_name="__main__"
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     )
     ^
   File "<frozen runpy>", line 287, in run_path
   File "<frozen runpy>", line 98, in _run_module_code
   File "<frozen runpy>", line 88, in _run_code
   File "./tools/sched_ext/scx_show_state.py", line 30, in <module>
     ops = prog['scx_ops']
           ~~~~^^^^^^^^^^^
 _drgn.ObjectNotFoundError: could not find 'scx_ops'

Fixes: 48e126777386 ("sched_ext: Introduce scx_sched")
Signed-off-by: Kohei Enju <enjuk@amazon.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
sched_ext: Drop "ops" from scx_ops_bypass(), scx_ops_breather() and friends 2025-04-04T18:52:49+00:00 Tejun Heo tj@kernel.org 2025-04-04T18:52:49+00:00 8c6ee862467e8632cb72dc753c75a561ff5693d2 The tag "ops" is used for two different purposes. First, to indicate that the entity is directly related to the operations such as flags carried in sched_ext_ops. Second, to indicate that the entity applies to something global such as enable or bypass states. The second usage is historical and causes confusion rather than clarifying anything. For example, scx_ops_enable_state enums are named SCX_OPS_* and thus conflict with scx_ops_flags. Let's drop the second usages. Drop "ops" from scx_ops_bypass(), scx_ops_breather() and friends. Update scx_show_state.py accordingly. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Andrea Righi <arighi@nvidia.com> 
The tag "ops" is used for two different purposes. First, to indicate that
the entity is directly related to the operations such as flags carried in
sched_ext_ops. Second, to indicate that the entity applies to something
global such as enable or bypass states. The second usage is historical and
causes confusion rather than clarifying anything. For example,
scx_ops_enable_state enums are named SCX_OPS_* and thus conflict with
scx_ops_flags. Let's drop the second usages.

Drop "ops" from scx_ops_bypass(), scx_ops_breather() and friends. Update
scx_show_state.py accordingly.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Andrea Righi <arighi@nvidia.com>
sched_ext: Drop "ops" from scx_ops_helper, scx_ops_enable_mutex and __scx_ops_enabled 2025-04-04T18:52:48+00:00 Tejun Heo tj@kernel.org 2025-04-04T18:52:48+00:00 a50c365f996d8935c52967391488828e5e76471e The tag "ops" is used for two different purposes. First, to indicate that the entity is directly related to the operations such as flags carried in sched_ext_ops. Second, to indicate that the entity applies to something global such as enable or bypass states. The second usage is historical and causes confusion rather than clarifying anything. For example, scx_ops_enable_state enums are named SCX_OPS_* and thus conflict with scx_ops_flags. Let's drop the second usages. Drop "ops" from scx_ops_helper, scx_ops_enable_mutex and __scx_ops_enabled. Update scx_show_state.py accordingly. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Andrea Righi <arighi@nvidia.com> 
The tag "ops" is used for two different purposes. First, to indicate that
the entity is directly related to the operations such as flags carried in
sched_ext_ops. Second, to indicate that the entity applies to something
global such as enable or bypass states. The second usage is historical and
causes confusion rather than clarifying anything. For example,
scx_ops_enable_state enums are named SCX_OPS_* and thus conflict with
scx_ops_flags. Let's drop the second usages.

Drop "ops" from scx_ops_helper, scx_ops_enable_mutex and __scx_ops_enabled.
Update scx_show_state.py accordingly.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Andrea Righi <arighi@nvidia.com>
sched_ext: Drop "ops" from scx_ops_enable_state and friends 2025-04-04T18:52:48+00:00 Tejun Heo tj@kernel.org 2025-04-04T18:52:48+00:00 1a7ff7216c8b4d199033c292ce5acf8e9cdb5dc2 The tag "ops" is used for two different purposes. First, to indicate that the entity is directly related to the operations such as flags carried in sched_ext_ops. Second, to indicate that the entity applies to something global such as enable or bypass states. The second usage is historical and causes confusion rather than clarifying anything. For example, scx_ops_enable_state enums are named SCX_OPS_* and thus conflict with scx_ops_flags. Let's drop the second usages. Drop "ops" from scx_ops_enable_state and friends. Update scx_show_state.py accordingly. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Andrea Righi <arighi@nvidia.com> 
The tag "ops" is used for two different purposes. First, to indicate that
the entity is directly related to the operations such as flags carried in
sched_ext_ops. Second, to indicate that the entity applies to something
global such as enable or bypass states. The second usage is historical and
causes confusion rather than clarifying anything. For example,
scx_ops_enable_state enums are named SCX_OPS_* and thus conflict with
scx_ops_flags. Let's drop the second usages.

Drop "ops" from scx_ops_enable_state and friends. Update scx_show_state.py
accordingly.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Andrea Righi <arighi@nvidia.com>
sched_ext: Enable the ops breather and eject BPF scheduler on softlockup 2024-11-08T20:42:22+00:00 Tejun Heo tj@kernel.org 2024-11-05T21:49:04+00:00 e32c260195e6ff72940ab7826e38e0a0066fc58f On 2 x Intel Sapphire Rapids machines with 224 logical CPUs, a poorly behaving BPF scheduler can live-lock the system by making multiple CPUs bang on the same DSQ to the point where soft-lockup detection triggers before SCX's own watchdog can take action. It also seems possible that the machine can be live-locked enough to prevent scx_ops_helper, which is an RT task, from running in a timely manner. Implement scx_softlockup() which is called when three quarters of soft-lockup threshold has passed. The function immediately enables the ops breather and triggers an ops error to initiate ejection of the BPF scheduler. The previous and this patch combined enable the kernel to reliably recover the system from live-lock conditions that can be triggered by a poorly behaving BPF scheduler on Intel dual socket systems. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Douglas Anderson <dianders@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> 
On 2 x Intel Sapphire Rapids machines with 224 logical CPUs, a poorly
behaving BPF scheduler can live-lock the system by making multiple CPUs bang
on the same DSQ to the point where soft-lockup detection triggers before
SCX's own watchdog can take action. It also seems possible that the machine
can be live-locked enough to prevent scx_ops_helper, which is an RT task,
from running in a timely manner.

Implement scx_softlockup() which is called when three quarters of
soft-lockup threshold has passed. The function immediately enables the ops
breather and triggers an ops error to initiate ejection of the BPF
scheduler.

The previous and this patch combined enable the kernel to reliably recover
the system from live-lock conditions that can be triggered by a poorly
behaving BPF scheduler on Intel dual socket systems.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
sched_ext: Update scx_show_state.py to match scx_ops_bypass_depth's new type 2024-11-05T21:45:27+00:00 Tejun Heo tj@kernel.org 2024-11-05T21:45:27+00:00 a759bf0dfc4db3cb6556fc79c7c98da3a46b2b80 0e7ffff1b811 ("scx: Fix raciness in scx_ops_bypass()") converted scx_ops_bypass_depth from an atomic to an int. Update scx_show_state.py accordingly. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 0e7ffff1b811 ("scx: Fix raciness in scx_ops_bypass()") 
0e7ffff1b811 ("scx: Fix raciness in scx_ops_bypass()") converted
scx_ops_bypass_depth from an atomic to an int. Update scx_show_state.py
accordingly.

Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 0e7ffff1b811 ("scx: Fix raciness in scx_ops_bypass()")
sched_ext: Provide a sysfs enable_seq counter 2024-09-23T16:53:02+00:00 Andrea Righi andrea.righi@linux.dev 2024-09-21T19:39:21+00:00 431844b65f4c1b988ccd886f2ed29c138f7bb262 As discussed during the distro-centric session within the sched_ext Microconference at LPC 2024, introduce a sequence counter that is incremented every time a BPF scheduler is loaded. This feature can help distributions in diagnosing potential performance regressions by identifying systems where users are running (or have ran) custom BPF schedulers. Example: arighi@virtme-ng~> cat /sys/kernel/sched_ext/enable_seq 0 arighi@virtme-ng~> sudo scx_simple local=1 global=0 ^CEXIT: unregistered from user space arighi@virtme-ng~> cat /sys/kernel/sched_ext/enable_seq 1 In this way user-space tools (such as Ubuntu's apport and similar) are able to gather and include this information in bug reports. Cc: Giovanni Gherdovich <giovanni.gherdovich@suse.com> Cc: Kleber Sacilotto de Souza <kleber.souza@canonical.com> Cc: Marcelo Henrique Cerri <marcelo.cerri@canonical.com> Cc: Phil Auld <pauld@redhat.com> Signed-off-by: Andrea Righi <andrea.righi@linux.dev> Signed-off-by: Tejun Heo <tj@kernel.org> 
As discussed during the distro-centric session within the sched_ext
Microconference at LPC 2024, introduce a sequence counter that is
incremented every time a BPF scheduler is loaded.

This feature can help distributions in diagnosing potential performance
regressions by identifying systems where users are running (or have ran)
custom BPF schedulers.

Example:

 arighi@virtme-ng~> cat /sys/kernel/sched_ext/enable_seq
 0
 arighi@virtme-ng~> sudo scx_simple
 local=1 global=0
 ^CEXIT: unregistered from user space
 arighi@virtme-ng~> cat /sys/kernel/sched_ext/enable_seq
 1

In this way user-space tools (such as Ubuntu's apport and similar) are
able to gather and include this information in bug reports.

Cc: Giovanni Gherdovich <giovanni.gherdovich@suse.com>
Cc: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Cc: Marcelo Henrique Cerri <marcelo.cerri@canonical.com>
Cc: Phil Auld <pauld@redhat.com>
Signed-off-by: Andrea Righi <andrea.righi@linux.dev>
Signed-off-by: Tejun Heo <tj@kernel.org>
tools/sched_ext: Add scx_show_state.py 2024-06-18T20:09:18+00:00 Tejun Heo tj@kernel.org 2024-06-18T20:09:18+00:00 1c3ae1cb2f2cf245d529fe363ce420ec8028a547 There are states which are interesting but don't quite fit the interface exposed under /sys/kernel/sched_ext. Add tools/scx_show_state.py to show them. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: David Vernet <dvernet@meta.com> 
There are states which are interesting but don't quite fit the interface
exposed under /sys/kernel/sched_ext. Add tools/scx_show_state.py to show
them.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: David Vernet <dvernet@meta.com>