From ab5e5b99a949b9f282c605d00557b2c727856485 Mon Sep 17 00:00:00 2001 From: Juri Lelli Date: Tue, 16 Jan 2024 17:19:26 +0100 Subject: tools/workqueue: Add rescuers printing to wq_dump.py Retrieving rescuers information (e.g., affinity and name) is quite useful when debugging workqueues configurations. Add printing of such information to the existing wq_dump.py script. Signed-off-by: Juri Lelli Signed-off-by: Tejun Heo --- tools/workqueue/wq_dump.py | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'tools/workqueue/wq_dump.py') diff --git a/tools/workqueue/wq_dump.py b/tools/workqueue/wq_dump.py index d0df5833f2c1..6da621989e21 100644 --- a/tools/workqueue/wq_dump.py +++ b/tools/workqueue/wq_dump.py @@ -175,3 +175,32 @@ for wq in list_for_each_entry('struct workqueue_struct', workqueues.address_of_( if wq.flags & WQ_UNBOUND: print(f' {wq.dfl_pwq.pool.id.value_():{max_pool_id_len}}', end='') print('') + +print('') +print('Workqueue -> rescuer') +print('=====================') +print(f'wq_unbound_cpumask={cpumask_str(wq_unbound_cpumask)}') +print('') +print('[ workqueue \ type unbound_cpumask rescuer pid cpumask]') + +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='') + print(f' {cpumask_str(wq.unbound_attrs.cpumask):24}', end='') + else: + print(' percpu ', end='') + print(' ', end='') + + if wq.flags & WQ_MEM_RECLAIM: + print(f' {wq.rescuer.task.comm.string_().decode()[-24:]:24}', end='') + print(f' {wq.rescuer.task.pid.value_():5}', end='') + print(f' {cpumask_str(wq.rescuer.task.cpus_ptr)}', end='') + print('') -- cgit v1.2.3 From a6b48c83d28e21ddcd6a080128bb73f9e3d130ac Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 25 Jan 2024 06:21:56 -1000 Subject: tools/workqueue/wq_dump.py: Clean up code and drop duplicate information - Factor out wq_type_str() - Improve formatting so that it adapts to actual field widths. - Drop duplicate information from "Workqueue -> rescuer" section. If anything, we should add more rescuer-specific info - e.g. the number of work items rescued. Signed-off-by: Tejun Heo Cc: Juri Lelli --- tools/workqueue/wq_dump.py | 69 +++++++++++++++++++++++----------------------- 1 file changed, 35 insertions(+), 34 deletions(-) (limited to 'tools/workqueue/wq_dump.py') diff --git a/tools/workqueue/wq_dump.py b/tools/workqueue/wq_dump.py index 6da621989e21..333b2fc00b82 100644 --- a/tools/workqueue/wq_dump.py +++ b/tools/workqueue/wq_dump.py @@ -75,6 +75,20 @@ def cpumask_str(cpumask): output += f'{v:08x}' return output.strip() +wq_type_len = 9 + +def wq_type_str(wq): + if wq.flags & WQ_UNBOUND: + if wq.flags & WQ_ORDERED: + return f'{"ordered":{wq_type_len}}' + else: + if wq.unbound_attrs.affn_strict: + return f'{"unbound,S":{wq_type_len}}' + else: + return f'{"unbound":{wq_type_len}}' + else: + return f'{"percpu":{wq_type_len}}' + worker_pool_idr = prog['worker_pool_idr'] workqueues = prog['workqueues'] wq_unbound_cpumask = prog['wq_unbound_cpumask'] @@ -92,6 +106,10 @@ WQ_AFFN_CACHE = prog['WQ_AFFN_CACHE'] WQ_AFFN_NUMA = prog['WQ_AFFN_NUMA'] WQ_AFFN_SYSTEM = prog['WQ_AFFN_SYSTEM'] +WQ_NAME_LEN = prog['WQ_NAME_LEN'].value_() + +cpumask_str_len = len(cpumask_str(wq_unbound_cpumask)) + print('Affinity Scopes') print('===============') @@ -148,24 +166,13 @@ print('') print('Workqueue CPU -> pool') print('=====================') -print('[ workqueue \ type CPU', end='') +print(f'[{"workqueue":^{WQ_NAME_LEN-2}}\\ {"type CPU":{wq_type_len}}', 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='') + print(f'{wq.name.string_().decode():{WQ_NAME_LEN}} {wq_type_str(wq):10}', end='') for cpu in for_each_possible_cpu(prog): pool_id = per_cpu_ptr(wq.cpu_pwq, cpu)[0].pool.id.value_() @@ -178,29 +185,23 @@ for wq in list_for_each_entry('struct workqueue_struct', workqueues.address_of_( print('') print('Workqueue -> rescuer') -print('=====================') -print(f'wq_unbound_cpumask={cpumask_str(wq_unbound_cpumask)}') -print('') -print('[ workqueue \ type unbound_cpumask rescuer pid cpumask]') +print('====================') + +ucpus_len = max(cpumask_str_len, len("unbound_cpus")) +rcpus_len = max(cpumask_str_len, len("rescuer_cpus")) + +print(f'[{"workqueue":^{WQ_NAME_LEN-2}}\\ {"unbound_cpus":{ucpus_len}} pid {"rescuer_cpus":{rcpus_len}} ]') 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='') - print(f' {cpumask_str(wq.unbound_attrs.cpumask):24}', end='') + if not (wq.flags & WQ_MEM_RECLAIM): + continue + + print(f'{wq.name.string_().decode():{WQ_NAME_LEN}}', end='') + if wq.unbound_attrs.value_() != 0: + print(f' {cpumask_str(wq.unbound_attrs.cpumask):{ucpus_len}}', end='') else: - print(' percpu ', end='') - print(' ', end='') + print(f' {"":{ucpus_len}}', end='') - if wq.flags & WQ_MEM_RECLAIM: - print(f' {wq.rescuer.task.comm.string_().decode()[-24:]:24}', end='') - print(f' {wq.rescuer.task.pid.value_():5}', end='') - print(f' {cpumask_str(wq.rescuer.task.cpus_ptr)}', end='') + print(f' {wq.rescuer.task.pid.value_():6}', end='') + print(f' {cpumask_str(wq.rescuer.task.cpus_ptr):{rcpus_len}}', end='') print('') -- cgit v1.2.3 From 07daa99b7fd7adfffa22180184e39ec124e73013 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 29 Jan 2024 08:11:25 -1000 Subject: tools/workqueue/wq_dump.py: Add node_nr/max_active dump Print out per-node nr/max_active numbers to improve visibility into node_nr_active operations. Signed-off-by: Tejun Heo --- tools/workqueue/wq_dump.py | 41 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 40 insertions(+), 1 deletion(-) (limited to 'tools/workqueue/wq_dump.py') diff --git a/tools/workqueue/wq_dump.py b/tools/workqueue/wq_dump.py index 333b2fc00b82..bd381511bd9a 100644 --- a/tools/workqueue/wq_dump.py +++ b/tools/workqueue/wq_dump.py @@ -50,6 +50,7 @@ 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.nodemask import for_each_node from drgn.helpers.linux.idr import idr_for_each import argparse @@ -107,7 +108,6 @@ WQ_AFFN_NUMA = prog['WQ_AFFN_NUMA'] WQ_AFFN_SYSTEM = prog['WQ_AFFN_SYSTEM'] WQ_NAME_LEN = prog['WQ_NAME_LEN'].value_() - cpumask_str_len = len(cpumask_str(wq_unbound_cpumask)) print('Affinity Scopes') @@ -205,3 +205,42 @@ for wq in list_for_each_entry('struct workqueue_struct', workqueues.address_of_( print(f' {wq.rescuer.task.pid.value_():6}', end='') print(f' {cpumask_str(wq.rescuer.task.cpus_ptr):{rcpus_len}}', end='') print('') + +print('') +print('Unbound workqueue -> node_nr/max_active') +print('=======================================') + +if 'node_to_cpumask_map' in prog: + __cpu_online_mask = prog['__cpu_online_mask'] + node_to_cpumask_map = prog['node_to_cpumask_map'] + nr_node_ids = prog['nr_node_ids'].value_() + + print(f'online_cpus={cpumask_str(__cpu_online_mask.address_of_())}') + for node in for_each_node(): + print(f'NODE[{node:02}]={cpumask_str(node_to_cpumask_map[node])}') + print('') + + print(f'[{"workqueue":^{WQ_NAME_LEN-2}}\\ min max', end='') + first = True + for node in for_each_node(): + if first: + print(f' NODE {node}', end='') + first = False + else: + print(f' {node:7}', end='') + print(f' {"dfl":>7} ]') + print('') + + for wq in list_for_each_entry('struct workqueue_struct', workqueues.address_of_(), 'list'): + if not (wq.flags & WQ_UNBOUND): + continue + + print(f'{wq.name.string_().decode():{WQ_NAME_LEN}} ', end='') + print(f'{wq.min_active.value_():3} {wq.max_active.value_():3}', end='') + for node in for_each_node(): + nna = wq.node_nr_active[node] + print(f' {nna.nr.counter.value_():3}/{nna.max.value_():3}', end='') + nna = wq.node_nr_active[nr_node_ids] + print(f' {nna.nr.counter.value_():3}/{nna.max.value_():3}') +else: + printf(f'node_to_cpumask_map not present, is NUMA enabled?') -- cgit v1.2.3 From 4cb1ef64609f9b0254184b2947824f4b46ccab22 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 4 Feb 2024 11:28:06 -1000 Subject: workqueue: Implement BH workqueues to eventually replace tasklets The only generic interface to execute asynchronously in the BH context is tasklet; however, it's marked deprecated and has some design flaws such as the execution code accessing the tasklet item after the execution is complete which can lead to subtle use-after-free in certain usage scenarios and less-developed flush and cancel mechanisms. This patch implements BH workqueues which share the same semantics and features of regular workqueues but execute their work items in the softirq context. As there is always only one BH execution context per CPU, none of the concurrency management mechanisms applies and a BH workqueue can be thought of as a convenience wrapper around softirq. Except for the inability to sleep while executing and lack of max_active adjustments, BH workqueues and work items should behave the same as regular workqueues and work items. Currently, the execution is hooked to tasklet[_hi]. However, the goal is to convert all tasklet users over to BH workqueues. Once the conversion is complete, tasklet can be removed and BH workqueues can directly take over the tasklet softirqs. system_bh[_highpri]_wq are added. As queue-wide flushing doesn't exist in tasklet, all existing tasklet users should be able to use the system BH workqueues without creating their own workqueues. v3: - Add missing interrupt.h include. v2: - Instead of using tasklets, hook directly into its softirq action functions - tasklet[_hi]_action(). This is slightly cheaper and closer to the eventual code structure we want to arrive at. Suggested by Lai. - Lai also pointed out several places which need NULL worker->task handling or can use clarification. Updated. Signed-off-by: Tejun Heo Suggested-by: Linus Torvalds Link: http://lkml.kernel.org/r/CAHk-=wjDW53w4-YcSmgKC5RruiRLHmJ1sXeYdp_ZgVoBw=5byA@mail.gmail.com Tested-by: Allen Pais Reviewed-by: Lai Jiangshan --- tools/workqueue/wq_dump.py | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'tools/workqueue/wq_dump.py') diff --git a/tools/workqueue/wq_dump.py b/tools/workqueue/wq_dump.py index bd381511bd9a..d29b918306b4 100644 --- a/tools/workqueue/wq_dump.py +++ b/tools/workqueue/wq_dump.py @@ -79,7 +79,9 @@ def cpumask_str(cpumask): wq_type_len = 9 def wq_type_str(wq): - if wq.flags & WQ_UNBOUND: + if wq.flags & WQ_BH: + return f'{"bh":{wq_type_len}}' + elif wq.flags & WQ_UNBOUND: if wq.flags & WQ_ORDERED: return f'{"ordered":{wq_type_len}}' else: @@ -97,6 +99,7 @@ wq_pod_types = prog['wq_pod_types'] wq_affn_dfl = prog['wq_affn_dfl'] wq_affn_names = prog['wq_affn_names'] +WQ_BH = prog['WQ_BH'] WQ_UNBOUND = prog['WQ_UNBOUND'] WQ_ORDERED = prog['__WQ_ORDERED'] WQ_MEM_RECLAIM = prog['WQ_MEM_RECLAIM'] @@ -107,6 +110,8 @@ WQ_AFFN_CACHE = prog['WQ_AFFN_CACHE'] WQ_AFFN_NUMA = prog['WQ_AFFN_NUMA'] WQ_AFFN_SYSTEM = prog['WQ_AFFN_SYSTEM'] +POOL_BH = prog['POOL_BH'] + WQ_NAME_LEN = prog['WQ_NAME_LEN'].value_() cpumask_str_len = len(cpumask_str(wq_unbound_cpumask)) @@ -151,10 +156,12 @@ for pi, pool in idr_for_each(worker_pool_idr): 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'pool[{pi:0{max_pool_id_len}}] flags=0x{pool.flags.value_():02x} 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='') + if pool.flags & POOL_BH: + print(' bh', end='') else: print(f'cpus={cpumask_str(pool.attrs.cpumask)}', end='') print(f' pod_cpus={cpumask_str(pool.attrs.__pod_cpumask)}', end='') -- cgit v1.2.3