[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20191219012914.GA6080@ming.t460p>
Date: Thu, 19 Dec 2019 09:29:14 +0800
From: Ming Lei <ming.lei@...hat.com>
To: Peter Zijlstra <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>, Jens Axboe <axboe@...nel.dk>,
linux-kernel@...r.kernel.org, linux-block@...r.kernel.org,
Long Li <longli@...rosoft.com>, Ingo Molnar <mingo@...hat.com>,
Keith Busch <keith.busch@...el.com>,
Christoph Hellwig <hch@....de>,
Sagi Grimberg <sagi@...mberg.me>,
John Garry <john.garry@...wei.com>,
Hannes Reinecke <hare@...e.com>
Subject: Re: [RFC PATCH 1/3] sched/core: add API for exporting runqueue clock
On Wed, Dec 18, 2019 at 10:51:01AM +0100, Peter Zijlstra wrote:
> On Wed, Dec 18, 2019 at 03:19:40PM +0800, Ming Lei wrote:
> > Scheduler runqueue maintains its own software clock that is periodically
> > synchronised with hardware. Export this clock so that it can be used
> > by interrupt flood detection for saving the cost of reading from hardware.
>
> But you don't have much, if any, guarantees the thing gets updated.
Any software clock won't be guaranteed to be updated in time, however,
they are still useful.
Thanks,
Ming
Powered by blists - more mailing lists