From: Peter Zijlstra <peterz@infradead.org>
To: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>, Steven Rostedt <rostedt@goodmis.org>,
linux-mm@kvack.org, Arnaldo Carvalho de Melo <acme@infradead.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
Christoph Hellwig <hch@infradead.org>,
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
Oleg Nesterov <oleg@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
SystemTap <systemtap@sources.redhat.com>,
Jim Keniston <jkenisto@linux.vnet.ibm.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Andi Kleen <andi@firstfloor.org>,
LKML <linux-kernel@vger.kernel.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: Re: [RFC] [PATCH 2.6.37-rc5-tip 5/20] 5: Uprobes: register/unregister probes.
Date: Wed, 26 Jan 2011 11:10:56 +0100 [thread overview]
Message-ID: <1296036656.28776.1137.camel@laptop> (raw)
In-Reply-To: <20110126074737.GA19725@linux.vnet.ibm.com>
On Wed, 2011-01-26 at 13:17 +0530, Srikar Dronamraju wrote:
> * Peter Zijlstra <peterz@infradead.org> [2011-01-25 13:15:45]:
>
> > > +
> > > + if (atomic_read(&uprobe->ref) == 1) {
> > > + synchronize_sched();
> > > + rb_erase(&uprobe->rb_node, &uprobes_tree);
> >
> > How is that safe without holding the treelock?
>
> Right,
> Something like this should be good enuf right?
>
> if (atomic_read(&uprobe->ref) == 1) {
> synchronize_sched();
> spin_lock_irqsave(&treelock, flags);
> rb_erase(&uprobe->rb_node, &uprobes_tree);
> spin_lock_irqrestore(&treelock, flags);
> iput(uprobe->inode);
> }
>
How is the atomic_read() not racy with a future increment, and what is
that synchronize_sched() thing for?
next prev parent reply other threads:[~2011-01-26 10:10 UTC|newest]
Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-16 9:57 [RFC] [PATCH 2.6.37-rc5-tip 0/20] 0: Inode based uprobes Srikar Dronamraju
2010-12-16 9:57 ` [RFC] [PATCH 2.6.37-rc5-tip 1/20] 1: mm: Move replace_page() / write_protect_page() to mm/memory.c Srikar Dronamraju
2010-12-16 9:57 ` [RFC] [PATCH 2.6.37-rc5-tip 2/20] 2: X86 specific breakpoint definitions Srikar Dronamraju
2010-12-16 9:57 ` [RFC] [PATCH 2.6.37-rc5-tip 3/20] 3: uprobes: Breakground page replacement Srikar Dronamraju
2010-12-16 9:58 ` [RFC] [PATCH 2.6.37-rc5-tip 4/20] 4: uprobes: Adding and remove a uprobe in a rb tree Srikar Dronamraju
2011-01-25 12:15 ` Peter Zijlstra
2011-01-26 8:37 ` Srikar Dronamraju
2011-01-25 12:15 ` Peter Zijlstra
2011-01-26 8:41 ` Srikar Dronamraju
2011-01-26 10:13 ` Peter Zijlstra
2011-01-25 12:15 ` Peter Zijlstra
2011-01-26 8:38 ` Srikar Dronamraju
2011-01-25 13:56 ` Peter Zijlstra
2011-01-26 8:45 ` Srikar Dronamraju
2011-01-26 10:14 ` Peter Zijlstra
2011-01-26 15:18 ` Srikar Dronamraju
2011-01-26 15:33 ` Peter Zijlstra
2010-12-16 9:58 ` [RFC] [PATCH 2.6.37-rc5-tip 5/20] 5: Uprobes: register/unregister probes Srikar Dronamraju
2011-01-25 12:15 ` Peter Zijlstra
2011-01-26 7:55 ` Srikar Dronamraju
2011-01-26 10:11 ` Peter Zijlstra
2011-01-26 15:30 ` Srikar Dronamraju
2011-01-26 15:45 ` Peter Zijlstra
2011-01-26 16:56 ` Srikar Dronamraju
2011-01-26 17:12 ` Peter Zijlstra
2011-01-27 10:01 ` Srikar Dronamraju
2011-01-27 10:23 ` Peter Zijlstra
2011-01-27 10:25 ` Srikar Dronamraju
2011-01-27 10:41 ` Peter Zijlstra
2011-01-27 10:29 ` Peter Zijlstra
2011-01-25 12:15 ` Peter Zijlstra
2011-01-26 7:47 ` Srikar Dronamraju
2011-01-26 10:10 ` Peter Zijlstra [this message]
2010-12-16 9:58 ` [RFC] [PATCH 2.6.37-rc5-tip 6/20] 6: x86: analyze instruction and determine fixups Srikar Dronamraju
2010-12-16 9:58 ` [RFC] [PATCH 2.6.37-rc5-tip 7/20] 7: uprobes: store/restore original instruction Srikar Dronamraju
2011-01-25 12:15 ` Peter Zijlstra
2010-12-16 9:58 ` [RFC] [PATCH 2.6.37-rc5-tip 8/20] 8: uprobes: mmap and fork hooks Srikar Dronamraju
2011-01-25 12:15 ` Peter Zijlstra
2011-01-26 9:03 ` Srikar Dronamraju
2011-01-26 10:20 ` Peter Zijlstra
2011-01-26 14:59 ` Srikar Dronamraju
2011-01-26 15:16 ` Peter Zijlstra
2011-01-26 16:30 ` Srikar Dronamraju
2011-01-25 12:15 ` Peter Zijlstra
2011-01-25 20:05 ` Steven Rostedt
2011-01-26 9:06 ` Srikar Dronamraju
2011-01-27 17:03 ` Steven Rostedt
2011-01-28 4:53 ` Srikar Dronamraju
2011-01-28 13:57 ` Steven Rostedt
2011-01-28 14:28 ` Steven Rostedt
2011-01-28 14:46 ` Srikar Dronamraju
2011-01-28 15:02 ` Steven Rostedt
2011-01-26 15:09 ` Srikar Dronamraju
2011-01-26 15:20 ` Peter Zijlstra
2010-12-16 9:58 ` [RFC] [PATCH 2.6.37-rc5-tip 9/20] 9: x86: architecture specific task information Srikar Dronamraju
2010-12-16 9:59 ` [RFC] [PATCH 2.6.37-rc5-tip 10/20] 10: uprobes: task specific information Srikar Dronamraju
2011-01-25 13:56 ` Peter Zijlstra
2011-01-25 18:38 ` Josh Stone
2011-01-25 18:55 ` Roland McGrath
2011-01-25 19:56 ` Peter Zijlstra
2010-12-16 9:59 ` [RFC] [PATCH 2.6.37-rc5-tip 11/20] 11: uprobes: slot allocation for uprobes Srikar Dronamraju
2011-01-25 13:56 ` Peter Zijlstra
2010-12-16 9:59 ` [RFC] [PATCH 2.6.37-rc5-tip 12/20] 12: uprobes: get the breakpoint address Srikar Dronamraju
2011-01-25 13:56 ` Peter Zijlstra
2010-12-16 9:59 ` [RFC] [PATCH 2.6.37-rc5-tip 13/20] 13: x86: x86 specific probe handling Srikar Dronamraju
2011-01-25 13:56 ` Peter Zijlstra
2011-01-27 9:40 ` Srikar Dronamraju
2011-01-27 10:22 ` Peter Zijlstra
2011-01-27 19:11 ` Roland McGrath
2011-01-28 4:57 ` Srikar Dronamraju
2011-01-28 6:23 ` Roland McGrath
2011-01-28 8:36 ` Peter Zijlstra
2011-01-28 18:23 ` Roland McGrath
2010-12-16 9:59 ` [RFC] [PATCH 2.6.37-rc5-tip 14/20] 14: uprobes: Handing int3 and singlestep exception Srikar Dronamraju
2011-01-25 13:56 ` Peter Zijlstra
2011-01-25 13:56 ` Peter Zijlstra
2011-01-26 8:52 ` Srikar Dronamraju
2011-01-26 10:17 ` Peter Zijlstra
2011-01-26 15:14 ` Srikar Dronamraju
2011-01-26 15:29 ` Peter Zijlstra
2010-12-16 10:00 ` [RFC] [PATCH 2.6.37-rc5-tip 15/20] 15: x86: uprobes exception notifier for x86 Srikar Dronamraju
2010-12-16 10:00 ` [RFC] [PATCH 2.6.37-rc5-tip 16/20] 16: uprobes: register a notifier for uprobes Srikar Dronamraju
2011-01-25 13:56 ` Peter Zijlstra
2011-01-27 6:50 ` Srikar Dronamraju
2010-12-16 10:00 ` [RFC] [PATCH 2.6.37-rc5-tip 17/20] 17: uprobes: filter chain Srikar Dronamraju
2010-12-16 10:00 ` [RFC] [PATCH 2.6.37-rc5-tip 18/20] 18: uprobes: commonly used filters Srikar Dronamraju
2010-12-17 19:32 ` Valdis.Kletnieks
2010-12-18 3:04 ` Srikar Dronamraju
2010-12-16 10:00 ` [RFC] [PATCH 2.6.37-rc5-tip 19/20] 19: tracing: Extract out common code for kprobes/uprobes traceevents Srikar Dronamraju
2010-12-16 10:01 ` [RFC] [PATCH 2.6.37-rc5-tip 20/20] 20: tracing: uprobes trace_event interface Srikar Dronamraju
2010-12-16 10:07 ` [RFC] [PATCH 2.6.37-rc5-tip 0/20] 0: Inode based uprobes Srikar Dronamraju
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