From: Emanuele Rocca <ema@debian.org>
To: Mike Galbraith <efault@gmx.de>
Cc: linux-kernel@vger.kernel.org, Michal Hocko <mhocko@suse.com>
Subject: Re: Runtime overhead of PREEMPT_DYNAMIC
Date: Fri, 20 Oct 2023 16:45:06 +0200 [thread overview]
Message-ID: <ZTKScoO9kz_LxNMG@ariel> (raw)
In-Reply-To: <15e4768144a74b093ad5a43f6e5c263fd98775fb.camel@gmx.de>
On 2023-10-20 04:34, Mike Galbraith wrote:
> Hm, I don't recall the overhead as being that bad, but thar she blows.
>
> i7-4790 avg cmdline
> 6.5.8-voluntary 3685.08 3679.93 3704.98 3689.99 1.000
> 6.5.8-dynamic 3571.62 3568.61 3550.55 3563.59 .965
> 3052.06 3032.74 3019.93 3034.91 .822 +DEBUG_PREEMPT
> 3651.37 3599.87 3615.18 3622.14 .981 preempt=none
> 3459.58 3514.09 3539.88 3504.51 .949 preempt=full
Perfect, that's in line with my measurements (~20% overhead). Debian
kernels have CONFIG_DEBUG_PREEMPT=y, it seems wise to set it to 'n'
instead. Thank you.
prev parent reply other threads:[~2023-10-20 14:42 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-20 9:14 Runtime overhead of PREEMPT_DYNAMIC Emanuele Rocca
2023-10-20 12:42 ` Mike Galbraith
2023-10-20 13:40 ` Emanuele Rocca
2023-10-20 14:11 ` Mike Galbraith
2023-10-20 14:34 ` Mike Galbraith
2023-10-20 14:45 ` Emanuele Rocca [this message]
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