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From: "Stefan (metze) Metzmacher" <metze@samba.org>
To: Dave Chiluk <chiluk@canonical.com>
Cc: Steve French <sfrench@samba.org>,
	linux-cifs@vger.kernel.org, samba-technical@lists.samba.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] CIFS: Decrease reconnection delay when switching nics
Date: Wed, 27 Feb 2013 12:06:14 +0100	[thread overview]
Message-ID: <512DE8A6.9030000@samba.org> (raw)
In-Reply-To: <1361831310-24260-1-git-send-email-chiluk@canonical.com>

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Hi Dave,

> When messages are currently in queue awaiting a response, decrease amount of
> time before attempting cifs_reconnect to SMB_MAX_RTT = 10 seconds. The current
> wait time before attempting to reconnect is currently 2*SMB_ECHO_INTERVAL(120
> seconds) since the last response was recieved.  This does not take into account
> the fact that messages waiting for a response should be serviced within a
> reasonable round trip time.

Wouldn't that mean that the client will disconnect a good connection,
if the server doesn't response within 10 seconds?
Reads and Writes can take longer than 10 seconds...

> This fixes the issue where user moves from wired to wireless or vice versa
> causing the mount to hang for 120 seconds, when it could reconnect considerably
> faster.  After this fix it will take SMB_MAX_RTT (10 seconds) from the last
> time the user attempted to access the volume or SMB_MAX_RTT after the last
> echo.  The worst case of the latter scenario being
> 2*SMB_ECHO_INTERVAL+SMB_MAX_RTT+small scheduling delay (about 130 seconds).
> Statistically speaking it would normally reconnect sooner.  However in the best
> case where the user changes nics, and immediately tries to access the cifs
> share it will take SMB_MAX_RTT=10 seconds.

I think it would be better to detect the broken connection
by using an AF_NETLINK socket listening for RTM_DELADDR
messages?

metze


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  reply	other threads:[~2013-02-27 11:12 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-25 22:28 [PATCH] CIFS: Decrease reconnection delay when switching nics Dave Chiluk
2013-02-27 11:06 ` Stefan (metze) Metzmacher [this message]
2013-02-27 16:34   ` Jeff Layton
2013-02-27 22:24     ` Dave Chiluk
2013-02-27 22:40       ` Steve French
2013-02-27 22:44         ` Dave Chiluk
2013-02-28  0:17           ` Stefan (metze) Metzmacher
2013-02-28  1:25           ` simo
2013-02-28  1:26           ` Tom Talpey
2013-02-28 15:26       ` Jeff Layton
2013-02-28 16:04         ` Steve French
2013-02-28 16:47           ` Jeff Layton
2013-02-28 17:31             ` Dave Chiluk
2013-02-28 17:45               ` Steve French
2013-02-28 18:04               ` Jeff Layton
2013-02-28 22:23               ` simo
2013-02-28 22:54         ` Björn JACKE
2013-03-01  0:11           ` Jeff Layton
2013-03-01  2:54             ` Steve French
2013-02-28  0:15     ` Stefan (metze) Metzmacher
2013-02-28 13:01       ` Tom Talpey

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