diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-09-02 02:06:32 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-09-02 02:06:32 +0300 |
commit | bd30fe6a7d9b72e73c5ac9109cbc3066dde08034 (patch) | |
tree | a6226ddb8011ea278e1ad81586add9f7a8d15faa /tools | |
parent | 7716f383a58314378604eecdd66949ea2cd80ef3 (diff) | |
parent | fe48ba7daefe75bbbefa2426deddc05f2d530d2d (diff) | |
download | linux-bd30fe6a7d9b72e73c5ac9109cbc3066dde08034.tar.xz |
Merge tag 'wq-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue updates from Tejun Heo:
- Unbound workqueues now support more flexible affinity scopes.
The default behavior is to soft-affine according to last level cache
boundaries. A work item queued from a given LLC is executed by a
worker running on the same LLC but the worker may be moved across
cache boundaries as the scheduler sees fit. On machines which
multiple L3 caches, which are becoming more popular along with
chiplet designs, this improves cache locality while not harming work
conservation too much.
Unbound workqueues are now also a lot more flexible in terms of
execution affinity. Differeing levels of affinity scopes are
supported and both the default and per-workqueue affinity settings
can be modified dynamically. This should help working around amny of
sub-optimal behaviors observed recently with asymmetric ARM CPUs.
This involved signficant restructuring of workqueue code. Nothing was
reported yet but there's some risk of subtle regressions. Should keep
an eye out.
- Rescuer workers now has more identifiable comms.
- workqueue.unbound_cpus added so that CPUs which can be used by
workqueue can be constrained early during boot.
- Now that all the in-tree users have been flushed out, trigger warning
if system-wide workqueues are flushed.
* tag 'wq-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (31 commits)
workqueue: fix data race with the pwq->stats[] increment
workqueue: Rename rescuer kworker
workqueue: Make default affinity_scope dynamically updatable
workqueue: Add "Affinity Scopes and Performance" section to documentation
workqueue: Implement non-strict affinity scope for unbound workqueues
workqueue: Add workqueue_attrs->__pod_cpumask
workqueue: Factor out need_more_worker() check and worker wake-up
workqueue: Factor out work to worker assignment and collision handling
workqueue: Add multiple affinity scopes and interface to select them
workqueue: Modularize wq_pod_type initialization
workqueue: Add tools/workqueue/wq_dump.py which prints out workqueue configuration
workqueue: Generalize unbound CPU pods
workqueue: Factor out clearing of workqueue-only attrs fields
workqueue: Factor out actual cpumask calculation to reduce subtlety in wq_update_pod()
workqueue: Initialize unbound CPU pods later in the boot
workqueue: Move wq_pod_init() below workqueue_init()
workqueue: Rename NUMA related names to use pod instead
workqueue: Rename workqueue_attrs->no_numa to ->ordered
workqueue: Make unbound workqueues to use per-cpu pool_workqueues
workqueue: Call wq_update_unbound_numa() on all CPUs in NUMA node on CPU hotplug
...
Diffstat (limited to 'tools')
-rw-r--r-- | tools/workqueue/wq_dump.py | 177 | ||||
-rw-r--r-- | tools/workqueue/wq_monitor.py | 21 |
2 files changed, 191 insertions, 7 deletions
diff --git a/tools/workqueue/wq_dump.py b/tools/workqueue/wq_dump.py new file mode 100644 index 000000000000..d0df5833f2c1 --- /dev/null +++ b/tools/workqueue/wq_dump.py @@ -0,0 +1,177 @@ +#!/usr/bin/env drgn +# +# Copyright (C) 2023 Tejun Heo <tj@kernel.org> +# Copyright (C) 2023 Meta Platforms, Inc. and affiliates. + +desc = """ +This is a drgn script to show the current workqueue configuration. For more +info on drgn, visit https://github.com/osandov/drgn. + +Affinity Scopes +=============== + +Shows the CPUs that can be used for unbound workqueues and how they will be +grouped by each available affinity type. For each type: + + nr_pods number of CPU pods in the affinity type + pod_cpus CPUs in each pod + pod_node NUMA node for memory allocation for each pod + cpu_pod pod that each CPU is associated to + +Worker Pools +============ + +Lists all worker pools indexed by their ID. For each pool: + + ref number of pool_workqueue's associated with this pool + nice nice value of the worker threads in the pool + idle number of idle workers + workers number of all workers + cpu CPU the pool is associated with (per-cpu pool) + cpus CPUs the workers in the pool can run on (unbound pool) + +Workqueue CPU -> pool +===================== + +Lists all workqueues along with their type and worker pool association. For +each workqueue: + + NAME TYPE[,FLAGS] POOL_ID... + + NAME name of the workqueue + TYPE percpu, unbound or ordered + FLAGS S: strict affinity scope + POOL_ID worker pool ID associated with each possible CPU +""" + +import sys + +import drgn +from drgn.helpers.linux.list import list_for_each_entry,list_empty +from drgn.helpers.linux.percpu import per_cpu_ptr +from drgn.helpers.linux.cpumask import for_each_cpu,for_each_possible_cpu +from drgn.helpers.linux.idr import idr_for_each + +import argparse +parser = argparse.ArgumentParser(description=desc, + formatter_class=argparse.RawTextHelpFormatter) +args = parser.parse_args() + +def err(s): + print(s, file=sys.stderr, flush=True) + sys.exit(1) + +def cpumask_str(cpumask): + output = "" + base = 0 + v = 0 + for cpu in for_each_cpu(cpumask[0]): + while cpu - base >= 32: + output += f'{hex(v)} ' + base += 32 + v = 0 + v |= 1 << (cpu - base) + if v > 0: + output += f'{v:08x}' + return output.strip() + +worker_pool_idr = prog['worker_pool_idr'] +workqueues = prog['workqueues'] +wq_unbound_cpumask = prog['wq_unbound_cpumask'] +wq_pod_types = prog['wq_pod_types'] +wq_affn_dfl = prog['wq_affn_dfl'] +wq_affn_names = prog['wq_affn_names'] + +WQ_UNBOUND = prog['WQ_UNBOUND'] +WQ_ORDERED = prog['__WQ_ORDERED'] +WQ_MEM_RECLAIM = prog['WQ_MEM_RECLAIM'] + +WQ_AFFN_CPU = prog['WQ_AFFN_CPU'] +WQ_AFFN_SMT = prog['WQ_AFFN_SMT'] +WQ_AFFN_CACHE = prog['WQ_AFFN_CACHE'] +WQ_AFFN_NUMA = prog['WQ_AFFN_NUMA'] +WQ_AFFN_SYSTEM = prog['WQ_AFFN_SYSTEM'] + +print('Affinity Scopes') +print('===============') + +print(f'wq_unbound_cpumask={cpumask_str(wq_unbound_cpumask)}') + +def print_pod_type(pt): + print(f' nr_pods {pt.nr_pods.value_()}') + + print(' pod_cpus', end='') + for pod in range(pt.nr_pods): + print(f' [{pod}]={cpumask_str(pt.pod_cpus[pod])}', end='') + print('') + + print(' pod_node', end='') + for pod in range(pt.nr_pods): + print(f' [{pod}]={pt.pod_node[pod].value_()}', end='') + print('') + + print(f' cpu_pod ', end='') + for cpu in for_each_possible_cpu(prog): + print(f' [{cpu}]={pt.cpu_pod[cpu].value_()}', end='') + print('') + +for affn in [WQ_AFFN_CPU, WQ_AFFN_SMT, WQ_AFFN_CACHE, WQ_AFFN_NUMA, WQ_AFFN_SYSTEM]: + print('') + print(f'{wq_affn_names[affn].string_().decode().upper()}{" (default)" if affn == wq_affn_dfl else ""}') + print_pod_type(wq_pod_types[affn]) + +print('') +print('Worker Pools') +print('============') + +max_pool_id_len = 0 +max_ref_len = 0 +for pi, pool in idr_for_each(worker_pool_idr): + pool = drgn.Object(prog, 'struct worker_pool', address=pool) + max_pool_id_len = max(max_pool_id_len, len(f'{pi}')) + max_ref_len = max(max_ref_len, len(f'{pool.refcnt.value_()}')) + +for pi, pool in idr_for_each(worker_pool_idr): + pool = drgn.Object(prog, 'struct worker_pool', address=pool) + print(f'pool[{pi:0{max_pool_id_len}}] ref={pool.refcnt.value_():{max_ref_len}} nice={pool.attrs.nice.value_():3} ', end='') + print(f'idle/workers={pool.nr_idle.value_():3}/{pool.nr_workers.value_():3} ', end='') + if pool.cpu >= 0: + print(f'cpu={pool.cpu.value_():3}', end='') + else: + print(f'cpus={cpumask_str(pool.attrs.cpumask)}', end='') + print(f' pod_cpus={cpumask_str(pool.attrs.__pod_cpumask)}', end='') + if pool.attrs.affn_strict: + print(' strict', end='') + print('') + +print('') +print('Workqueue CPU -> pool') +print('=====================') + +print('[ workqueue \ type CPU', end='') +for cpu in for_each_possible_cpu(prog): + print(f' {cpu:{max_pool_id_len}}', end='') +print(' dfl]') + +for wq in list_for_each_entry('struct workqueue_struct', workqueues.address_of_(), 'list'): + print(f'{wq.name.string_().decode()[-24:]:24}', end='') + if wq.flags & WQ_UNBOUND: + if wq.flags & WQ_ORDERED: + print(' ordered ', end='') + else: + print(' unbound', end='') + if wq.unbound_attrs.affn_strict: + print(',S ', end='') + else: + print(' ', end='') + else: + print(' percpu ', end='') + + for cpu in for_each_possible_cpu(prog): + pool_id = per_cpu_ptr(wq.cpu_pwq, cpu)[0].pool.id.value_() + field_len = max(len(str(cpu)), max_pool_id_len) + print(f' {pool_id:{field_len}}', end='') + + if wq.flags & WQ_UNBOUND: + print(f' {wq.dfl_pwq.pool.id.value_():{max_pool_id_len}}', end='') + print('') diff --git a/tools/workqueue/wq_monitor.py b/tools/workqueue/wq_monitor.py index 6e258d123e8c..a8856a9c45dc 100644 --- a/tools/workqueue/wq_monitor.py +++ b/tools/workqueue/wq_monitor.py @@ -20,8 +20,11 @@ https://github.com/osandov/drgn. and got excluded from concurrency management to avoid stalling other work items. - CMwake The number of concurrency-management wake-ups while executing a - work item of the workqueue. + CMW/RPR For per-cpu workqueues, the number of concurrency-management + wake-ups while executing a work item of the workqueue. For + unbound workqueues, the number of times a worker was repatriated + to its affinity scope after being migrated to an off-scope CPU by + the scheduler. mayday The number of times the rescuer was requested while waiting for new worker creation. @@ -65,6 +68,7 @@ PWQ_STAT_COMPLETED = prog['PWQ_STAT_COMPLETED'] # work items completed exec PWQ_STAT_CPU_TIME = prog['PWQ_STAT_CPU_TIME'] # total CPU time consumed PWQ_STAT_CPU_INTENSIVE = prog['PWQ_STAT_CPU_INTENSIVE'] # wq_cpu_intensive_thresh_us violations PWQ_STAT_CM_WAKEUP = prog['PWQ_STAT_CM_WAKEUP'] # concurrency-management worker wakeups +PWQ_STAT_REPATRIATED = prog['PWQ_STAT_REPATRIATED'] # unbound workers brought back into scope PWQ_STAT_MAYDAY = prog['PWQ_STAT_MAYDAY'] # maydays to rescuer PWQ_STAT_RESCUED = prog['PWQ_STAT_RESCUED'] # linked work items executed by rescuer PWQ_NR_STATS = prog['PWQ_NR_STATS'] @@ -89,22 +93,25 @@ class WqStats: 'cpu_time' : self.stats[PWQ_STAT_CPU_TIME], 'cpu_intensive' : self.stats[PWQ_STAT_CPU_INTENSIVE], 'cm_wakeup' : self.stats[PWQ_STAT_CM_WAKEUP], + 'repatriated' : self.stats[PWQ_STAT_REPATRIATED], 'mayday' : self.stats[PWQ_STAT_MAYDAY], 'rescued' : self.stats[PWQ_STAT_RESCUED], } def table_header_str(): return f'{"":>24} {"total":>8} {"infl":>5} {"CPUtime":>8} '\ - f'{"CPUitsv":>7} {"CMwake":>7} {"mayday":>7} {"rescued":>7}' + f'{"CPUitsv":>7} {"CMW/RPR":>7} {"mayday":>7} {"rescued":>7}' def table_row_str(self): cpu_intensive = '-' - cm_wakeup = '-' + cmw_rpr = '-' mayday = '-' rescued = '-' - if not self.unbound: + if self.unbound: + cmw_rpr = str(self.stats[PWQ_STAT_REPATRIATED]); + else: cpu_intensive = str(self.stats[PWQ_STAT_CPU_INTENSIVE]) - cm_wakeup = str(self.stats[PWQ_STAT_CM_WAKEUP]) + cmw_rpr = str(self.stats[PWQ_STAT_CM_WAKEUP]) if self.mem_reclaim: mayday = str(self.stats[PWQ_STAT_MAYDAY]) @@ -115,7 +122,7 @@ class WqStats: f'{max(self.stats[PWQ_STAT_STARTED] - self.stats[PWQ_STAT_COMPLETED], 0):5} ' \ f'{self.stats[PWQ_STAT_CPU_TIME] / 1000000:8.1f} ' \ f'{cpu_intensive:>7} ' \ - f'{cm_wakeup:>7} ' \ + f'{cmw_rpr:>7} ' \ f'{mayday:>7} ' \ f'{rescued:>7} ' return out.rstrip(':') |