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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Sitsofe Wheeler <sitsofe@gmail.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jason Wang <jasowang@redhat.com>,
	linux-kernel@vger.kernel.org,
	"David S. Miller" <davem@davemloft.net>,
	Daniel Borkmann <dborkman@redhat.com>,
	netdev@vger.kernel.org, devel@linuxdriverproject.org,
	Haiyang Zhang <haiyangz@microsoft.com>
Subject: Re: [hyperv] BUG at drivers/hv/channel.c:462 while changing MTU
Date: Mon, 25 Aug 2014 12:36:48 +0300	[thread overview]
Message-ID: <20140825093648.GB5046@mwanda> (raw)
In-Reply-To: <20140819123655.GC12160@sucs.org>

The code here is:

drivers/hv/channel.c
   460          BUG_ON(ret != 0);
   461          t = wait_for_completion_timeout(&info->waitevent, 5*HZ);
   462          BUG_ON(t == 0);

So it calls BUG_ON() if the teardown takes more than 5 seconds.  It's
most likely that there is a race condition somewhere.  It's also
possible that it's just taking longer than 5 seconds for some odd
reason and the bug would go away if we raised it to 60 seconds.

BUG_ON() after 5 seconds seems like a very aggressive thing.

regards,
dan carpenter


WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Sitsofe Wheeler <sitsofe@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jason Wang <jasowang@redhat.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	linux-kernel@vger.kernel.org,
	Daniel Borkmann <dborkman@redhat.com>,
	netdev@vger.kernel.org, devel@linuxdriverproject.org,
	"David S. Miller" <davem@davemloft.net>
Subject: Re: [hyperv] BUG at drivers/hv/channel.c:462 while changing MTU
Date: Mon, 25 Aug 2014 12:36:48 +0300	[thread overview]
Message-ID: <20140825093648.GB5046@mwanda> (raw)
In-Reply-To: <20140819123655.GC12160@sucs.org>

The code here is:

drivers/hv/channel.c
   460          BUG_ON(ret != 0);
   461          t = wait_for_completion_timeout(&info->waitevent, 5*HZ);
   462          BUG_ON(t == 0);

So it calls BUG_ON() if the teardown takes more than 5 seconds.  It's
most likely that there is a race condition somewhere.  It's also
possible that it's just taking longer than 5 seconds for some odd
reason and the bug would go away if we raised it to 60 seconds.

BUG_ON() after 5 seconds seems like a very aggressive thing.

regards,
dan carpenter

  parent reply	other threads:[~2014-08-25  9:37 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-08-19 12:36 [hyperv] BUG at drivers/hv/channel.c:462 while changing MTU Sitsofe Wheeler
2014-08-19 12:36 ` Sitsofe Wheeler
2014-08-19 21:29 ` Haiyang Zhang
2014-08-20  3:41   ` Sitsofe Wheeler
2014-08-20  3:41     ` Sitsofe Wheeler
2014-08-25 10:48     ` Richard Weinberger
2014-08-25 10:48       ` Richard Weinberger
2014-08-25 14:53       ` KY Srinivasan
2014-08-25 14:53         ` KY Srinivasan
2014-08-25 15:07         ` Richard Weinberger
2014-08-25 15:07           ` Richard Weinberger
2014-08-25 17:29           ` KY Srinivasan
2014-08-25 17:29             ` KY Srinivasan
2014-08-25  9:36 ` Dan Carpenter [this message]
2014-08-25  9:36   ` Dan Carpenter
2014-08-25 17:34   ` KY Srinivasan
2014-08-25 17:50     ` Greg Kroah-Hartman
2014-08-25 17:50       ` Greg Kroah-Hartman
2014-08-25 18:05       ` KY Srinivasan
2014-08-25 18:05         ` KY Srinivasan
2014-08-25 21:43   ` Sitsofe Wheeler
2014-08-25 21:43     ` Sitsofe Wheeler
2014-08-25 21:48     ` KY Srinivasan
2014-08-25 21:48       ` KY Srinivasan
2014-08-27  9:33       ` Sitsofe Wheeler
2014-08-27  9:33         ` Sitsofe Wheeler

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