From: Kay Sievers <kay.sievers@vrfy.org>
To: linux-hotplug@vger.kernel.org
Subject: Re: [PATCH] closing the loop -- retries and acks
Date: Wed, 18 Feb 2004 08:27:19 +0000 [thread overview]
Message-ID: <20040218082719.GA9050@vrfy.org> (raw)
In-Reply-To: <403305A3.2070604@sympatico.ca>
On Wed, Feb 18, 2004 at 01:26:43AM -0500, Chris Friesen wrote:
> This patch reduces the already low chances of lost messages.
>
> Once udevsend successfully sends a message, it waits with a timeout for
> a response. If the response is good, then all is well, otherwise it
> sends the message again.
>
> In udevd, when we receive a request we store the address of the
> requestor, and then once the request has been handled we then send an
> ack back so that they know they have been taken care of.
>
> This patch takes care of the basics, but there are still a few things left:
> 1) tuning timeouts and retry numbers
> 2) capabilities check on the ack
> 3) pull out the udevd-specific stuff from struct hotplug_msg so that we
> don't waste time/memory. udevd will have a different struct, one
> element of which is hotplug_msg. udevsend still only knows about
> hotplug_msg
> 4) pull the messaging stuff into a set of headers or something to get
> rid of code duplication
>
> Comments?
It's sweet.
But isn't the case of handling a lost a message purely theroretical?
What problem we actually have is solved with this infrastructure?
A possibly crashing or exiting udevd in the time window from accepting
our message until its execution? Is the handling of this special case
really needed? Oh, and we don't handle a crashing udev :)
We have a remaining risk all over the place and it seems that we try to
look better than the whole picture. We have failure paths with much
much higher propability.
So, it's nice, sure.
But is it worth the extra complexity?
thanks,
Kay
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next prev parent reply other threads:[~2004-02-18 8:27 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-02-18 6:26 [PATCH] closing the loop -- retries and acks Chris Friesen
2004-02-18 8:27 ` Kay Sievers [this message]
2004-02-19 5:44 ` Chris Friesen
2004-02-19 7:52 ` Kay Sievers
2004-02-21 0:43 ` Greg KH
2004-02-21 0:44 ` Greg KH
2004-02-22 3:48 ` Chris Friesen
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