Messages in this thread | | | Date | Wed, 11 Oct 2023 18:30:24 +0800 | From | Chen Yu <> | Subject | Re: [PATCH] sched/fair: Use printk_deferred instead of printk in pick_eevdf() |
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On 2023-10-10 at 08:26:00 -0400, Phil Auld wrote: > On Tue, Oct 10, 2023 at 09:59:28AM +0200 Peter Zijlstra wrote: > > On Tue, Oct 10, 2023 at 11:25:41AM +0800, Chen Yu wrote: > > > When no eligible entity is found in pick_eevdf(), it has to pick > > > the entity with smallest vruntime. This indicates a potential issue > > > and scheduler will print this error. > > > > > > However this printk could introduce possible circular locking issue > > > because when the code path reaches here with the rq lock held, the > > > printk could trigger further scheduling which loops back to the > > > scheduler. > > > > > > Use printk_deferred() to defer the console write from current context > > > to the irq work in the next tick. > > Chen: I was not actually suggesting you make this change, just answering your > question about printk/rq lock. You don't need to put that line in there. >
Phil,
Sorry for misunderstanding that, and thanks again for your guidance.
thanks, Chenyu
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