Messages in this thread |  | | Date | Tue, 21 Oct 2014 15:14:45 +0200 | From | Michal Hocko <> | Subject | Re: [PATCH 3/4] OOM, PM: OOM killed task shouldn't escape PM suspend |
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On Tue 21-10-14 14:09:27, Rafael J. Wysocki wrote: [...] > > @@ -131,12 +132,40 @@ int freeze_processes(void) > > > > printk("Freezing user space processes ... "); > > pm_freezing = true; > > + oom_kills_saved = oom_kills_count(); > > error = try_to_freeze_tasks(true); > > if (!error) { > > - printk("done."); > > __usermodehelper_set_disable_depth(UMH_DISABLED); > > oom_killer_disable(); > > + > > + /* > > + * There might have been an OOM kill while we were > > + * freezing tasks and the killed task might be still > > + * on the way out so we have to double check for race. > > + */ > > + if (oom_kills_count() != oom_kills_saved) { > > + struct task_struct *g, *p; > > + > > + read_lock(&tasklist_lock); > > + for_each_process_thread(g, p) { > > + if (p == current || freezer_should_skip(p) || > > + frozen(p)) > > + continue; > > + error = -EBUSY; > > + goto out_loop; > > + } > > +out_loop: > > Well, it looks like this will work here too: > > for_each_process_thread(g, p) > if (p != current && !frozen(p) && > !freezer_should_skip(p)) { > error = -EBUSY; > break; > } > > or I am helplessly misreading the code.
break will not work because for_each_process_thread is a double loop. Except for that the negated condition is OK as well. I can change that if you prefer.
> > + read_unlock(&tasklist_lock); > > + > > + if (error) { > > + __usermodehelper_set_disable_depth(UMH_ENABLED); > > + printk("OOM in progress."); > > + goto done; > > + } > > + } > > + printk("done."); > > } > > +done: > > printk("\n"); > > BUG_ON(in_atomic()); > > -- Michal Hocko SUSE Labs
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