From: Greg KH <greg@kroah.com>
To: linux-hotplug@vger.kernel.org
Subject: Re: [RFC] reliability and scalability
Date: Sat, 07 Feb 2004 19:31:37 +0000 [thread overview]
Message-ID: <20040207193137.GC5003@kroah.com> (raw)
In-Reply-To: <40249B59.7080805@sympatico.ca>
On Sat, Feb 07, 2004 at 03:01:29AM -0500, Chris Friesen wrote:
>
> I've got a couple more ideas for improving udevd, but before I go crazy
> with this I wanted to get some opinions from people more experienced
> than me.
>
> First, how paranoid should we be about reliability? Right now there is a
> (low) possibility of udevd crashing with unhandled messages on its rx
> buffer, thus losing one or more hotplug events. Is this a problem?
> Would people welcome a patch that closes the loop by sending an ack back
> to udevsend?
I would welcome this. We really don't want to loose events. But how
long should udevsend wait before retrying the message? I can see this
getting messy...
> Second, how many udev instances are we expecting to have outstanding at
> a time?
As many as possible? :)
> There are a couple of places in udevd (specifically the devpath
> check and the udev_done code) that with the current data structures end
> up being worst case ofO(n^2). Is this a problem? The average user will
> never have an issue, but if we suddenly plug in a few thousand disks (a
> number that's been mentioned before), is it a big deal if it takes a
> bit longer to add them all? I see ways of getting around this, but
> it may be overkill.
This is very easy to test with scsi-debug. I don't really think this is
a issue right now, but if you want to try improving it a bit, please do.
thanks,
greg k-h
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next prev parent reply other threads:[~2004-02-07 19:31 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-02-07 8:01 [RFC] reliability and scalability Chris Friesen
2004-02-07 8:57 ` Olaf Hering
2004-02-07 9:49 ` Kay Sievers
2004-02-07 19:30 ` Greg KH
2004-02-07 19:31 ` Greg KH [this message]
2004-02-07 20:20 ` Olaf Hering
2004-02-09 3:59 ` Kay Sievers
2004-02-21 1:01 ` Greg KH
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