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From: Evgeniy Polyakov <zbr@ioremap.net>
To: Oliver Neukum <oliver@neukum.org>
Cc: Andy Grover <andy.grover@oracle.com>,
	rdreier@cisco.com, rds-devel@oss.oracle.com,
	general@lists.openfabrics.org, netdev@vger.kernel.org
Subject: Re: [PATCH 06/21] RDS: Connection handling
Date: Tue, 27 Jan 2009 16:51:44 +0300	[thread overview]
Message-ID: <20090127135144.GC18119@ioremap.net> (raw)
In-Reply-To: <200901271447.29377.oliver@neukum.org>

On Tue, Jan 27, 2009 at 02:47:27PM +0100, Oliver Neukum (oliver@neukum.org) wrote:
> > > +static inline int rds_conn_is_sending(struct rds_connection *conn)
> > > +{
> > > +	int ret = 0;
> > > +
> > > +	if (!mutex_trylock(&conn->c_send_lock))
> > > +		ret = 1;
> > > +	else
> > > +		mutex_unlock(&conn->c_send_lock);
> > > +
> > > +	return ret;
> > > +}
> > > +
> > 
> > This one is eventually invoked under the spin_lock with turned off irqs,
> > which may freeze the machine:
> > rds_for_each_conn_info() -> spin_lock_irqsave(global lock) ->
> > rds_conn_info_visitor() -> rds_conn_info_set() -> rds_conn_is_sending()
> > -> boom.
> 
> Why? This is _trylock. It won't block.

Unlock may reschedule.

-- 
	Evgeniy Polyakov

  reply	other threads:[~2009-01-27 13:51 UTC|newest]

Thread overview: 64+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-01-27  2:17 [ofa-general] [PATCH 0/21] Reliable Datagram Sockets (RDS) Andy Grover
2009-01-27  2:17 ` [ofa-general] [PATCH 01/21] RDS: Socket interface Andy Grover
2009-01-27  3:46   ` Stephen Hemminger
2009-01-29  3:17     ` [ofa-general] " Andrew Grover
2009-01-27  4:11   ` David Miller
2009-01-29 20:22     ` [ofa-general] ***SPAM*** " Andrew Grover
2009-01-27 12:08   ` Evgeniy Polyakov
2009-01-29  4:02     ` [ofa-general] " Andrew Grover
2009-01-29 16:24       ` Evgeniy Polyakov
2009-01-27  2:17 ` [ofa-general] [PATCH 02/21] RDS: Main header file Andy Grover
2009-01-27  7:34   ` Rémi Denis-Courmont
2009-01-27 19:27     ` [ofa-general] " Andrew Grover
2009-01-27 13:05   ` Evgeniy Polyakov
2009-01-27 19:23     ` [ofa-general] ***SPAM*** " Andrew Grover
2009-01-27 19:24       ` Steve Wise
2009-01-27  2:17 ` [PATCH 03/21] RDS: Congestion-handling code Andy Grover
2009-01-27  3:48   ` Stephen Hemminger
2009-01-27 19:15     ` Andrew Grover
2009-01-27 13:10   ` Evgeniy Polyakov
2009-01-27 19:10     ` Andrew Grover
2009-01-28 22:57   ` Roland Dreier
2009-01-29  2:39     ` [ofa-general] " Andy Grover
2009-01-27  2:17 ` [PATCH 04/21] RDS: Transport code Andy Grover
2009-01-27 13:18   ` Evgeniy Polyakov
2009-01-27 19:36     ` Andrew Grover
2009-01-27 21:56       ` [ofa-general] " Evgeniy Polyakov
2009-01-27 22:15         ` [ofa-general] ***SPAM*** " Andrew Grover
2009-01-27  2:17 ` [ofa-general] [PATCH 05/21] RDS: Info and stats Andy Grover
2009-01-27 13:28   ` Evgeniy Polyakov
2009-01-27  2:17 ` [PATCH 06/21] RDS: Connection handling Andy Grover
2009-01-27 13:34   ` Evgeniy Polyakov
2009-01-27 13:47     ` Oliver Neukum
2009-01-27 13:51       ` Evgeniy Polyakov [this message]
2009-01-27 16:28       ` [ofa-general] " Steve Wise
2009-01-29  3:03         ` ***SPAM*** " Andrew Grover
2009-01-29  8:03           ` Evgeniy Polyakov
2009-01-27  2:17 ` [PATCH 07/21] RDS: loopback Andy Grover
2009-01-27  2:17 ` [PATCH 08/21] RDS: sysctls Andy Grover
2009-01-27  2:17 ` [PATCH 09/21] RDS: Message parsing Andy Grover
2009-01-27  2:17 ` [PATCH 10/21] RDS: send.c Andy Grover
2009-01-27  2:17 ` [PATCH 11/21] RDS: recv.c Andy Grover
2009-01-27  2:17 ` [PATCH 12/21] RDS: RDMA support Andy Grover
2009-01-27  2:17 ` [ofa-general] [PATCH 13/21] RDS/IB: Infiniband transport Andy Grover
2009-01-27  2:17 ` [PATCH 14/21] RDS/IB: Ring-handling code Andy Grover
2009-01-27  2:17 ` [PATCH 15/21] RDS/IB: Implement RDMA ops using FMRs Andy Grover
2009-01-27  2:17 ` [PATCH 16/21] RDS/IB: Implement IB-specific datagram send Andy Grover
2009-01-27  2:17 ` [PATCH 17/21] RDS/IB: Receive datagrams via IB Andy Grover
2009-01-29  0:05   ` [ofa-general] " Roland Dreier
2009-01-29  2:20     ` Andy Grover
2009-01-29 21:02       ` Olaf Kirch
2009-01-29 21:47         ` [ofa-general] " Roland Dreier
2009-01-27  2:17 ` [PATCH 18/21] RDS/IB: Stats and sysctls Andy Grover
2009-01-27  2:17 ` [PATCH 19/21] RDS: Documentation Andy Grover
2009-01-27  2:17 ` [PATCH 20/21] RDS: Kconfig and Makefile Andy Grover
2009-01-28 22:59   ` Roland Dreier
2009-01-29  2:19     ` [ofa-general] " Andy Grover
2009-01-29  5:14       ` Roland Dreier
2009-01-27  2:17 ` [PATCH 21/21] RDS: Add AF and PF #defines for RDS sockets Andy Grover
2009-01-27  7:27   ` Rémi Denis-Courmont
2009-01-27 19:31     ` [ofa-general] " Andrew Grover
2009-01-27 15:34 ` [ofa-general] [PATCH 0/21] Reliable Datagram Sockets (RDS) Steve Wise
2009-01-27 19:29   ` ***SPAM*** " Andrew Grover
2009-01-28 22:37 ` Roland Dreier
2009-01-29  1:29   ` [ofa-general] " Andy Grover

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