From: Qian Cai <cai@gmx.us>
To: Thomas Gleixner <tglx@linutronix.de>, Waiman Long <longman@redhat.com>
Cc: linux kernel <linux-kernel@vger.kernel.org>,
arnd@arndb.de, Andrew Morton <akpm@linux-foundation.org>,
Yang Shi <yang.shi@linux.alibaba.com>
Subject: Re: [PATCH] debugobjects: add a new Kconfig for POOL_SIZE
Date: Mon, 19 Nov 2018 11:32:38 -0500 [thread overview]
Message-ID: <1542645158.12945.43.camel@gmx.us> (raw)
In-Reply-To: <alpine.DEB.2.21.1811191722270.1669@nanos.tec.linutronix.de>
On Mon, 2018-11-19 at 17:25 +0100, Thomas Gleixner wrote:
> On Mon, 19 Nov 2018, Waiman Long wrote:
> > On 11/19/2018 10:17 AM, Qian Cai wrote:
> > > Right, I can remember that now . However, if I understand correctly, since
> > > the
> > > early static pool size needs to be determined during the compilation time,
> > > it
> > > depends on the No. CPUs are from the machines that built the distro
> > > kernels.
> > > Then, when users use those distro kernels, they are not going to have
> > > correct
> > > the pool size according to the No. CPUs on their test machines.
> >
> > I see your point. Perhaps you can make ODEBUG_POOL_SIZE scales with
> > CONFIG_NR_CPUS like
> >
> > #define ODEBUG_POOL_SIZE (1024 + CONFIG_NR_CPUS * 2)
> >
> > CONFIG_NR_CPUS is usually set to a lot higher than the actual number of
> > CPUs in a typical system. So you don't want to set the multiplier too high.
>
> The number of CPUs on the build machine is totally irrelevant and not
> influencing the build at all. The sizing solely depends on CONFIG_NR_CPUS.
>
> And even if the initial pool is a bit oversized, it's init data and freed,
> so no real harm done.
>
Ah, I thought you meant the NR_CPUS macro. It is CONFIG_NR_CPUS, and we are
on the same page.
next prev parent reply other threads:[~2018-11-19 16:37 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-18 8:22 [PATCH] debugobjects: add a new Kconfig for POOL_SIZE Qian Cai
2018-11-18 18:21 ` Thomas Gleixner
2018-11-18 18:56 ` Qian Cai
2018-11-19 8:09 ` Thomas Gleixner
2018-11-19 13:27 ` Qian Cai
2018-11-19 14:51 ` Waiman Long
2018-11-19 15:17 ` Qian Cai
2018-11-19 16:19 ` Waiman Long
2018-11-19 16:25 ` Thomas Gleixner
2018-11-19 16:32 ` Qian Cai [this message]
2018-11-18 22:08 ` [PATCH v2] " Qian Cai
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