From: Ingo Molnar <mingo@elte.hu>
To: Arjan van de Ven <arjanv@redhat.com>
Cc: Anton Blanchard <anton@samba.org>,
linux-kernel@vger.kernel.org,
viro@parcelfarce.linux.theplanet.co.uk, wli@holomorphy.com
Subject: Re: /proc/sys/kernel/pid_max issues
Date: Sun, 12 Sep 2004 15:41:37 +0200 [thread overview]
Message-ID: <20040912134137.GA20136@elte.hu> (raw)
In-Reply-To: <20040912124420.GA29587@devserv.devel.redhat.com>
* Arjan van de Ven <arjanv@redhat.com> wrote:
> On Sun, Sep 12, 2004 at 10:30:00PM +1000, Anton Blanchard wrote:
> >
> > Hmm can you point the 16bit counter out? I can create 1 million NPTL
> > threads on ppc64 easily, so why not?
>
> /*
> * the semaphore definition
> */
> struct rw_semaphore {
> /* XXX this should be able to be an atomic_t -- paulus */
> signed int count;
> #define RWSEM_UNLOCKED_VALUE 0x00000000
> #define RWSEM_ACTIVE_BIAS 0x00000001
> #define RWSEM_ACTIVE_MASK 0x0000ffff
>
> that counter is split in 2 16 bit entities....
the generic semaphore code can handle up to ~2^31 waiters. I once tried
it on x86, it seems to work fine.
Ingo
next prev parent reply other threads:[~2004-09-12 13:40 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-09-12 8:56 /proc/sys/kernel/pid_max issues Anton Blanchard
2004-09-12 9:36 ` William Lee Irwin III
2004-09-12 9:51 ` Ingo Molnar
2004-09-12 9:58 ` William Lee Irwin III
2004-09-12 10:10 ` William Lee Irwin III
2004-09-12 10:13 ` Ingo Molnar
2004-09-12 10:43 ` William Lee Irwin III
2004-09-12 10:45 ` William Lee Irwin III
2004-09-12 11:08 ` William Lee Irwin III
2004-09-12 11:20 ` Ingo Molnar
2004-09-12 17:13 ` William Lee Irwin III
2004-09-12 18:02 ` Chris Wedgwood
2004-09-12 23:06 ` William Lee Irwin III
2004-09-13 1:46 ` [pidhashing] rewrite alloc_pidmap() William Lee Irwin III
2004-09-12 9:39 ` /proc/sys/kernel/pid_max issues Ingo Molnar
2004-09-12 9:43 ` William Lee Irwin III
2004-09-12 12:18 ` Arjan van de Ven
2004-09-12 12:30 ` Anton Blanchard
2004-09-12 12:44 ` Arjan van de Ven
2004-09-12 13:34 ` Anton Blanchard
2004-09-12 13:41 ` Ingo Molnar [this message]
-- strict thread matches above, loose matches on Subject: below --
2004-09-13 3:20 Albert Cahalan
2004-09-13 7:42 ` William Lee Irwin III
2004-09-13 14:11 ` Albert Cahalan
2004-09-13 14:27 ` William Lee Irwin III
2004-09-13 14:51 ` Herbert Poetzl
2004-09-14 2:13 ` William Lee Irwin III
2004-09-23 13:13 ` Pavel Machek
2004-09-24 16:02 ` Martin Mares
2004-09-23 13:11 ` Pavel Machek
2004-09-13 7:57 ` Ingo Molnar
2004-09-13 13:54 ` Albert Cahalan
2004-09-13 14:24 ` William Lee Irwin III
2004-09-13 14:54 ` Albert Cahalan
2004-09-14 2:02 ` William Lee Irwin III
2004-09-14 15:32 ` Ingo Molnar
2004-09-18 18:32 ` Pavel Machek
2004-09-23 13:18 ` Pavel Machek
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