By default fair_server dl_server allocates 5% of the bandwidth to the root domain. Due to this writing any value less than 5% fails due to -EBUSY: $ cat /proc/sys/kernel/sched_rt_period_us 1000000 $ echo 49999 > /proc/sys/kernel/sched_rt_runtime_us -bash: echo: write error: Device or resource busy $ echo 50000 > /proc/sys/kernel/sched_rt_runtime_us $ Since the sched_rt_runtime_us allows -1 as the minimum, put this restriction in the documentation. One should check average of runtime/period in /sys/kernel/debug/sched/fair_server/cpuX/* for exact value. Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lore.kernel.org/r/20250306052954.452005-3-sshegde@linux.ibm.com
Pull sched_ext updates from Tejun Heo: - scx_bpf_now() added so that BPF scheduler can access the cached timestamp in struct rq to avoid reading TSC multiple times within a locked scheduling operation. - Minor updates to the built-in idle CPU selection logic. - tool/sched_ext updates and other misc changes. * tag 'sched_ext-for-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: sched_ext: fix kernel-doc warnings sched_ext: Use time helpers in BPF schedulers sched_ext: Replace bpf_ktime_get_ns() to scx_bpf_now() sched_ext: Add time helpers for BPF schedulers sched_ext: Add scx_bpf_now() for BPF scheduler sched_ext: Implement scx_bpf_now() sched_ext: Relocate scx_enabled() related code sched_ext: Add option -l in selftest runner to list all available tests sched_ext: Include remaining task time slice in error state dump sched_ext: update scx_bpf_dsq_insert() doc for SCX_DSQ_LOCAL_ON sched_ext: idle: small CPU iteration refactoring sched_ext: idle: introduce check_builtin_idle_enabled() helper sched_ext: idle: clarify comments sched_ext: idle: use assign_cpu() to update the idle cpumask sched_ext: Use str_enabled_disabled() helper in update_selcpu_topology() sched_ext: Use sizeof_field for key_len in dsq_hash_params tools/sched_ext: Receive updates from SCX repo sched_ext: Use the NUMA scheduling domain for NUMA optimizations
Pull Documentation updates from Jonathan Corbet: - Quite a bit of Chinese and Spanish translation work - Clarifying that Git commit IDs >12chars are OK - A new nvme-multipath document - A reorganization of the admin-guide top-level page to make it readable - Clarification of the role of Acked-by and maintainer discretion on their acceptance - Some reorganization of debugging-oriented docs ... and typo fixes, documentation updates, etc as usual * tag 'docs-6.14' of git://git.lwn.net/linux: (50 commits) Documentation: Fix x86_64 UEFI outdated references to elilo Documentation/sysctl: Add timer_migration to kernel.rst docs/mm: Physical memory: Remove zone_t docs: submitting-patches: clarify that signers may use their discretion on tags docs: submitting-patches: clarify difference between Acked-by and Reviewed-by docs: submitting-patches: clarify Acked-by and introduce "# Suffix" Documentation: bug-hunting.rst: remove odd contact information docs/zh_CN: Add sak index Chinese translation doc: module: DEFAULT_SYMBOL_NAMESPACE must be defined before #includes doc: module: Fix documented type of namespace Documentation/kernel-parameters: Fix a reference to vga-softcursor.rst docs/zh_CN: Add landlock index Chinese translation Documentation: Fix typo localmodonfig -> localmodconfig overlayfs.rst: Fix and improve grammar docs/zh_CN: Add siphash index Chinese translation docs/zh_CN: Add security IMA-templates Chinese translation docs/zh_CN: Add security digsig Chinese translation Align git commit ID abbreviation guidelines and checks docs: process: submitting-patches: split canonical patch format section docs/zh_CN: Add security lsm Chinese translation ...
With commit 5b26f7b920f7 ("sched_ext: Allow SCX_DSQ_LOCAL_ON for direct
dispatches"), scx_bpf_dsq_insert() can use SCX_DSQ_LOCAL_ON for direct
dispatch from ops.enqueue() to target the local DSQ of any CPU.
Update the documentation accordingly.
Fixes: 5b26f7b920f7 ("sched_ext: Allow SCX_DSQ_LOCAL_ON for direct dispatches")
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Update the Schedstat version to 17 as more fields are added to report different kinds of imbalances in the sched domain. Also domain field started printing corresponding domain name. Signed-off-by: Swapnil Sapkal <swapnil.sapkal@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20241220063224.17767-7-swapnil.sapkal@amd.com
This has slightly changed with the introduction of fair_server. Update the most relevant parts. Link: https://lore.kernel.org/r/Z0c8S8i3qt7SEU14@jlelli-thinkpadt14gen4.remote.csb/ Signed-off-by: Michal Koutný <mkoutny@suse.com> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Acked-by: Juri Lelli <juri.lelli@redhat.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20241211170052.2449581-1-mkoutny@suse.com
:kyb: is an extra markup that we should avoid when we can. It worsens the plain-text reading experience and adds very little value to rendered views. Remove all :kbd: tags from Documentation/* Signed-off-by: Cengiz Can <cengiz@kernel.wtf> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20241202090514.1716-1-cengiz@kernel.wtf
In sched_ext API, a repeatedly reported pain point is the overuse of the verb "dispatch" and confusion around "consume": - ops.dispatch() - scx_bpf_dispatch[_vtime]() - scx_bpf_consume() - scx_bpf_dispatch[_vtime]_from_dsq*() This overloading of the term is historical. Originally, there were only built-in DSQs and moving a task into a DSQ always dispatched it for execution. Using the verb "dispatch" for the kfuncs to move tasks into these DSQs made sense. Later, user DSQs were added and scx_bpf_dispatch[_vtime]() updated to be able to insert tasks into any DSQ. The only allowed DSQ to DSQ transfer was from a non-local DSQ to a local DSQ and this operation was named "consume". This was already confusing as a task could be dispatched to a user DSQ from ops.enqueue() and then the DSQ would have to be consumed in ops.dispatch(). Later addition of scx_bpf_dispatch_from_dsq*() made the confusion even worse as "dispatch" in this context meant moving a task to an arbitrary DSQ from a user DSQ. Clean up the API with the following renames: 1. scx_bpf_dispatch[_vtime]() -> scx_bpf_dsq_insert[_vtime]() 2. scx_bpf_consume() -> scx_bpf_dsq_move_to_local() 3. scx_bpf_dispatch[_vtime]_from_dsq*() -> scx_bpf_dsq_move[_vtime]*() This patch performs the second rename. Compatibility is maintained by: - The previous kfunc names are still provided by the kernel so that old binaries can run. Kernel generates a warning when the old names are used. - compat.bpf.h provides wrappers for the new names which automatically fall back to the old names when running on older kernels. They also trigger build error if old names are used for new builds. The compat features will be dropped after v6.15. v2: Comment and documentation updates. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Andrea Righi <arighi@nvidia.com> Acked-by: Changwoo Min <changwoo@igalia.com> Acked-by: Johannes Bechberger <me@mostlynerdless.de> Acked-by: Giovanni Gherdovich <ggherdovich@suse.com> Cc: Dan Schatzberg <dschatzberg@meta.com> Cc: Ming Yang <yougmark94@gmail.com>
In sched_ext API, a repeatedly reported pain point is the overuse of the verb "dispatch" and confusion around "consume": - ops.dispatch() - scx_bpf_dispatch[_vtime]() - scx_bpf_consume() - scx_bpf_dispatch[_vtime]_from_dsq*() This overloading of the term is historical. Originally, there were only built-in DSQs and moving a task into a DSQ always dispatched it for execution. Using the verb "dispatch" for the kfuncs to move tasks into these DSQs made sense. Later, user DSQs were added and scx_bpf_dispatch[_vtime]() updated to be able to insert tasks into any DSQ. The only allowed DSQ to DSQ transfer was from a non-local DSQ to a local DSQ and this operation was named "consume". This was already confusing as a task could be dispatched to a user DSQ from ops.enqueue() and then the DSQ would have to be consumed in ops.dispatch(). Later addition of scx_bpf_dispatch_from_dsq*() made the confusion even worse as "dispatch" in this context meant moving a task to an arbitrary DSQ from a user DSQ. Clean up the API with the following renames: 1. scx_bpf_dispatch[_vtime]() -> scx_bpf_dsq_insert[_vtime]() 2. scx_bpf_consume() -> scx_bpf_dsq_move_to_local() 3. scx_bpf_dispatch[_vtime]_from_dsq*() -> scx_bpf_dsq_move[_vtime]*() This patch performs the first set of renames. Compatibility is maintained by: - The previous kfunc names are still provided by the kernel so that old binaries can run. Kernel generates a warning when the old names are used. - compat.bpf.h provides wrappers for the new names which automatically fall back to the old names when running on older kernels. They also trigger build error if old names are used for new builds. The compat features will be dropped after v6.15. v2: Documentation updates. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Andrea Righi <arighi@nvidia.com> Acked-by: Changwoo Min <changwoo@igalia.com> Acked-by: Johannes Bechberger <me@mostlynerdless.de> Acked-by: Giovanni Gherdovich <ggherdovich@suse.com> Cc: Dan Schatzberg <dschatzberg@meta.com> Cc: Ming Yang <yougmark94@gmail.com>
Since the artifact paths for tools changed, we need to update the documentation to reflect that path. Signed-off-by: Devaansh-Kumar <devaanshk840@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>