From: Peter Zijlstra <peterz@infradead.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: mingo@kernel.org, rusty@rustcorp.com.au,
mathieu.desnoyers@efficios.com, oleg@redhat.com,
paulmck@linux.vnet.ibm.com, torvalds@linux-foundation.org,
linux-kernel@vger.kernel.org, andi@firstfloor.org,
rostedt@goodmis.org, tglx@linutronix.de,
Michel Lespinasse <walken@google.com>,
Andrea Arcangeli <aarcange@redhat.com>,
David Woodhouse <David.Woodhouse@intel.com>,
Rik van Riel <riel@redhat.com>
Subject: Re: [PATCH 6/8] rbtree: Implement generic latch_tree
Date: Thu, 19 Mar 2015 23:10:21 +0100 [thread overview]
Message-ID: <20150319221021.GT2896@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <20150319135833.5a844744936bd8fdafea7ed5@linux-foundation.org>
On Thu, Mar 19, 2015 at 01:58:33PM -0700, Andrew Morton wrote:
> On Thu, 19 Mar 2015 08:25:02 +0100 Peter Zijlstra <peterz@infradead.org> wrote:
>
> > On Wed, Mar 18, 2015 at 10:14:46PM -0700, Andrew Morton wrote:
> > > On Wed, 18 Mar 2015 14:36:32 +0100 Peter Zijlstra <peterz@infradead.org> wrote:
> > >
> > > > include/linux/rbtree_latch.h | 223 +++++++++++++++++++++++++++++++++++++++++++
> > >
> > > Did it really need to all be inlined?
> >
> > Without that you get actual function calls to the less() and comp()
> > operators. This way GCC can inline the lot even though its function
> > pointers.
> >
> > The typical RB tree user open-codes all this every single time.
>
> Is it a good tradeoff?
Is what? Writing it like this or open-coding it all?
For many archs (indirect) function calls are far more expensive than the
typical comparison.
next prev parent reply other threads:[~2015-03-19 22:10 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-18 13:36 [PATCH 0/8] latched RB-trees and __module_address() Peter Zijlstra
2015-03-18 13:36 ` [PATCH 1/8] module: Sanitize RCU usage and locking Peter Zijlstra
2015-03-20 3:36 ` Rusty Russell
2015-03-18 13:36 ` [PATCH 2/8] module: Annotate module version magic Peter Zijlstra
2015-03-18 13:36 ` [PATCH 3/8] module, jump_label: Fix module locking Peter Zijlstra
2015-03-20 4:26 ` Rusty Russell
2015-03-20 9:11 ` Peter Zijlstra
2015-03-18 13:36 ` [PATCH 4/8] rbtree: Make lockless searches non-fatal Peter Zijlstra
2015-03-18 13:36 ` [PATCH 5/8] seqlock: Better document raw_write_seqcount_latch() Peter Zijlstra
2015-03-18 14:29 ` Mathieu Desnoyers
2015-03-18 14:50 ` Peter Zijlstra
2015-03-18 13:36 ` [PATCH 6/8] rbtree: Implement generic latch_tree Peter Zijlstra
2015-03-18 16:20 ` Ingo Molnar
2015-03-19 5:14 ` Andrew Morton
2015-03-19 7:25 ` Peter Zijlstra
2015-03-19 20:58 ` Andrew Morton
2015-03-19 21:36 ` Steven Rostedt
2015-03-19 21:38 ` Steven Rostedt
2015-03-19 21:47 ` Andrew Morton
2015-03-19 21:54 ` Steven Rostedt
2015-03-19 22:12 ` Peter Zijlstra
2015-03-19 22:04 ` Peter Zijlstra
2015-03-20 9:50 ` Peter Zijlstra
2015-03-19 22:10 ` Peter Zijlstra [this message]
2015-03-18 13:36 ` [PATCH 7/8] module: Optimize __module_address() using a latched RB-tree Peter Zijlstra
2015-03-18 13:36 ` [PATCH 8/8] module: Use __module_address() for module_address_lookup() Peter Zijlstra
2015-03-18 14:21 ` [PATCH 0/8] latched RB-trees and __module_address() Christoph Hellwig
2015-03-18 14:38 ` Peter Zijlstra
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