From: Frederic Weisbecker <fweisbec@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Paul Mackerras <paulus@samba.org>
Subject: Re: [PATCH] perf: Store active software events in a hashlist
Date: Wed, 7 Apr 2010 14:09:10 +0200 [thread overview]
Message-ID: <20100407120909.GG5143@nowhere> (raw)
In-Reply-To: <1270641405.20295.803.camel@laptop>
On Wed, Apr 07, 2010 at 01:56:45PM +0200, Peter Zijlstra wrote:
> On Wed, 2010-04-07 at 13:52 +0200, Frederic Weisbecker wrote:
> > On Wed, Apr 07, 2010 at 11:02:26AM +0200, Peter Zijlstra wrote:
> > > On Mon, 2010-04-05 at 16:08 +0200, Frederic Weisbecker wrote:
> > > > +#define SWEVENT_HLIST_BITS 8
> > > > +#define SWEVENT_HLIST_SIZE ((1 << (SWEVENT_HLIST_BITS + 1)) - 1)
> > >
> > > That seems to result in 9 bits worth, doesn't it?
> >
> >
> > Oh right, I was confused, will zapp the + 1.
> >
>
> Also, what you're computing seems to be a mask, not a size
>
> So with BITS = 8, you want
> SIZE = 1<<BITS = 256
> MASK = SIZE-1 = 255
>
> right?
Oh right... damn I suck in maths...
prev parent reply other threads:[~2010-04-07 12:09 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-05 14:08 [PATCH] perf: Store active software events in a hashlist Frederic Weisbecker
2010-04-06 15:27 ` Peter Zijlstra
2010-04-07 9:04 ` Peter Zijlstra
2010-04-07 11:58 ` Frederic Weisbecker
2010-04-07 12:09 ` Peter Zijlstra
2010-04-08 19:39 ` [PATCH v2] " Frederic Weisbecker
2010-04-08 20:04 ` Eric Dumazet
2010-04-08 20:11 ` Frederic Weisbecker
2010-04-07 11:56 ` [PATCH] " Frederic Weisbecker
2010-04-07 11:58 ` Peter Zijlstra
2010-04-07 12:06 ` Frederic Weisbecker
2010-04-07 9:02 ` Peter Zijlstra
2010-04-07 11:52 ` Frederic Weisbecker
2010-04-07 11:56 ` Peter Zijlstra
2010-04-07 12:09 ` Frederic Weisbecker [this message]
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