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RCVD_COUNT_TWO(0.00)[2]; RECEIVED_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:106:10:150:64:167:received]; MID_RHS_MATCH_FROM(0.00)[]; DKIM_TRACE(0.00)[suse.de:+]; RCVD_VIA_SMTP_AUTH(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:url,suse.de:mid,suse.de:dkim,suse.de:email] X-Spam-Flag: NO X-Spam-Score: -4.51 X-Rspamd-Queue-Id: 2F68B5BCC5 X-Rspamd-Action: no action X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Spam-Level: Hi Am 30.10.25 um 17:20 schrieb Marco Crivellari: > Hi, > > === Current situation: problems === > > Let's consider a nohz_full system with isolated CPUs: wq_unbound_cpumask is > set to the housekeeping CPUs, for !WQ_UNBOUND the local CPU is selected. > > This leads to different scenarios if a work item is scheduled on an > isolated CPU where "delay" value is 0 or greater then 0: > schedule_delayed_work(, 0); > > This will be handled by __queue_work() that will queue the work item on the > current local (isolated) CPU, while: > > schedule_delayed_work(, 1); > > Will move the timer on an housekeeping CPU, and schedule the work there. > > Currently if a user enqueue a work item using schedule_delayed_work() the > used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use > WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to > schedule_work() that is using system_wq and queue_work(), that makes use > again of WORK_CPU_UNBOUND. > > This lack of consistency cannot be addressed without refactoring the API. > > === Recent changes to the WQ API === > > The following, address the recent changes in the Workqueue API: > > - commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq") > - commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag") > > The old workqueues will be removed in a future release cycle. > > === Introduced Changes by this series === > > 1) [P 1-2-3] Replace uses of system_wq and system_unbound_wq > > system_wq is a per-CPU workqueue, but his name is not clear. > system_unbound_wq is to be used when locality is not required. > > Because of that, system_wq has been replaced with system_percpu_wq, and > system_unbound_wq has been replaced with system_dfl_wq. From the description, I've found it hard to see if there's a change in semantics here. But this series is effectively about renaming AFAICT. If so, Reviewed-by: Thomas Zimmermann for all patches. Best regards Thomas > > Thanks! > > > Marco Crivellari (3): > drm/atomic-helper: replace use of system_unbound_wq with system_dfl_wq > drm/probe-helper: replace use of system_wq with system_percpu_wq > drm/self_refresh: replace use of system_wq with system_percpu_wq > > drivers/gpu/drm/drm_atomic_helper.c | 6 +++--- > drivers/gpu/drm/drm_probe_helper.c | 2 +- > drivers/gpu/drm/drm_self_refresh_helper.c | 2 +- > 3 files changed, 5 insertions(+), 5 deletions(-) > -- -- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)