linux-kernel - [PATCH tip/core/rcu 0/4] rcu inline, expedited, ->completed cleanups

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20091110213651.GA21411@linux.vnet.ibm.com>
Date:	Tue, 10 Nov 2009 13:36:51 -0800
From:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
To:	linux-kernel@...r.kernel.org
Cc:	mingo@...e.hu, laijs@...fujitsu.com, dipankar@...ibm.com,
	akpm@...ux-foundation.org, mathieu.desnoyers@...ymtl.ca,
	josh@...htriplett.org, dvhltc@...ibm.com, niv@...ibm.com,
	tglx@...utronix.de, peterz@...radead.org, rostedt@...dmis.org,
	Valdis.Kletnieks@...edu, dhowells@...hat.com
Subject: [PATCH tip/core/rcu 0/4] rcu inline, expedited, ->completed
	cleanups

This patchset contains a few fixes from testing and review of treercu.
The review was spurred by the earlier bugs.

1.	Some compilers don't like forward references to inline functions.
	Make the compiler happy by removing "inline".

2.	Although synchronize_sched_expedited() was implemented with a
	fastpath to efficiently handle multiple concurrent calls,
	the counter increment that enabled this fastpath was omitted.
	Add it back in.  (And yes, this does make a big difference in
	performance and scalability for multiple concurrent calls to
	synchronize_sched_expedited(), not that such calls should happen
	all that often.  Still, no point in bringing the machine to its
	knees unnecessarily.)

3.	The field rsp->dynticks_completed is now used whether or not
	dynticks is enabled.  Rename it to rsp->completed_fqs to better
	document its new role.

4.	Much of the confusion leading to the bugs provoked by testing
	with long RCU grace periods was due to the method used to
	determine which grace period a given context-switch quiescent
	state is to be applied to.  This change provides a much more
	straightforward detection method for these quiescent states.
	The quiescent states induced by force_quiescent_state() still
	use the old method, and a separate patch for them is in the
	works.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/