From: Daniel Wagner <wagi@monom.org>
To: Marouen Ghodhbane <marouen.ghodhbane@nxp.com>
Cc: "linux-rt-users@vger.kernel.org" <linux-rt-users@vger.kernel.org>
Subject: Re: complete_all warning with 3 waiters
Date: Thu, 12 Mar 2020 09:10:50 +0100 [thread overview]
Message-ID: <20200312081050.ldxfol4yupln7phw@beryllium.lan> (raw)
In-Reply-To: <DB3PR0402MB3708A4D019B384FE29CBDD96F6FC0@DB3PR0402MB3708.eurprd04.prod.outlook.com>
Hi Marouen,
On Wed, Mar 11, 2020 at 04:32:03PM +0000, Marouen Ghodhbane wrote:
> My question is: is there any good reason for the value of 2 in the
> warning condition ? It seems to me like a warning put earlier to
> check if we trigger this condition and work on some unresolved
> issues. Do we need another filter like the pm_in_action ?
The check is there to find code paths which rely on waking many
waiters. The problem is, swake_up_all_locked() is running while
holding a raw spin lock with irq disabled which can introduce unbouded
latencies on the system.
> Any idea/suggestion is definitely appreciated
The warning is harmless in your case though annoying.
Thanks,
Daniel
next prev parent reply other threads:[~2020-03-12 8:10 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-11 16:32 complete_all warning with 3 waiters Marouen Ghodhbane
2020-03-12 8:10 ` Daniel Wagner [this message]
2020-03-17 12:08 ` Sebastian Andrzej Siewior
2020-03-17 23:51 ` [EXT] " Marouen Ghodhbane
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