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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Oleksij Rempel <o.rempel@pengutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Jiri Slaby <jslaby@suse.com>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	lkml <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1 3/3] drivers/tty: increase priority for tty_buffer_worker
Date: Thu, 10 Jan 2019 17:30:30 +0100	[thread overview]
Message-ID: <20190110163030.GB19693@kroah.com> (raw)
In-Reply-To: <20190110151953.qpat4t7lat6plfk6@pengutronix.de>

On Thu, Jan 10, 2019 at 04:19:53PM +0100, Oleksij Rempel wrote:
> > My gut feel is that if somebody still cares deeply about serial line
> > latency, they should look at trying to see if they can do some of the
> > work directly without the bounce to the workqueue. We use workqueues
> > for a reason, but it's possible that some of it could be avoided at
> > least in special cases... And yours sounds like a special case.
> 
> It is for industrial low latency RS-422 based application. The loopback
> test is just easy way to test/reproduce it without additional hardware.
> 
> What is good, mainlineable way to implement it? 

What is the real problem your systems are having?  Are they serial-port
limited?  Is latency a big issue?  Trying to tune for a fake workload
isn't the best way to solve anything :)

thanks,
greg k-h

  reply	other threads:[~2019-01-10 16:30 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-10 10:12 [PATCH v1 0/3] reduce tty latency Oleksij Rempel
2019-01-10 10:12 ` [PATCH v1 1/3] drivers/tty: refactor functions for flushing/queuing work Oleksij Rempel
2019-03-11  8:16   ` Alexander Sverdlin
2019-01-10 10:12 ` [PATCH v1 2/3] drivers/tty: convert tty_port to use kthread_worker Oleksij Rempel
2019-03-11  8:23   ` Alexander Sverdlin
2019-01-10 10:12 ` [PATCH v1 3/3] drivers/tty: increase priority for tty_buffer_worker Oleksij Rempel
2019-01-10 12:54   ` Linus Torvalds
2019-01-10 15:19     ` Oleksij Rempel
2019-01-10 16:30       ` Greg Kroah-Hartman [this message]
2019-01-28  8:05         ` Oleksij Rempel
2019-01-28  8:23           ` Greg Kroah-Hartman
2019-01-28  9:22             ` Oleksij Rempel
2019-01-28 20:03               ` Linus Torvalds
2019-01-28 20:13                 ` Linus Torvalds
2019-01-10 16:59       ` Linus Torvalds
2019-03-11  8:24   ` Alexander Sverdlin
2019-01-10 13:51 ` [PATCH v1 0/3] reduce tty latency Greg Kroah-Hartman

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