From: Peter Zijlstra <peterz@infradead.org>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: Andi Kleen <andi@firstfloor.org>,
akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH 4/7] kref: Remove WARN_ON for NULL release functions
Date: Wed, 15 Mar 2017 13:27:31 +0100 [thread overview]
Message-ID: <20170315122731.GR3093@worktop> (raw)
In-Reply-To: <20170315024656.GA11886@kroah.com>
On Wed, Mar 15, 2017 at 10:46:56AM +0800, Greg KH wrote:
> On Tue, Mar 14, 2017 at 07:14:28PM -0700, Andi Kleen wrote:
> > From: Andi Kleen <ak@linux.intel.com>
> >
> > The kref functions check for NULL release functions.
> > This WARN_ON seems rather pointless. We will eventually release and
> > then just crash nicely. It is also somewhat expensive because
> > these functions are inlined in a lot of places.
> > Removing the WARN_ONs saves around 2.3k in this kernel
> > (likely more in others with more drivers)
> >
> > text data bss dec hex filename
> > 9083992 5367600 11116544 25568136 1862388 vmlinux-before-load-avg
> > 9070166 5367600 11116544 25554310 185ed86 vmlinux-load-avg
>
> WARN_ON() is heavy, didn't realize that.
I actually have patches fixing that.
next prev parent reply other threads:[~2017-03-15 12:27 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-15 2:14 Some inline debloating, 4.11 edition Andi Kleen
2017-03-15 2:14 ` [PATCH 1/7] trace: Move trace_seq_overflowed out of line Andi Kleen
2017-03-16 0:54 ` Steven Rostedt
2017-03-16 2:27 ` Andi Kleen
2017-03-16 3:20 ` Steven Rostedt
2017-03-16 3:41 ` Steven Rostedt
2017-03-15 2:14 ` [PATCH 2/7] x86/atomic: Move __atomic_add_unless " Andi Kleen
2017-03-15 2:14 ` [PATCH 3/7] sched: Out of line __update_load_avg Andi Kleen
2017-03-15 2:14 ` [PATCH 4/7] kref: Remove WARN_ON for NULL release functions Andi Kleen
2017-03-15 2:46 ` Greg KH
2017-03-15 12:27 ` Peter Zijlstra [this message]
2017-03-15 2:14 ` [PATCH 5/7] Out of line dma_alloc/free_attrs Andi Kleen
2017-03-15 2:14 ` [PATCH 6/7] megasas: Remove expensive inline from megasas_return_cmd Andi Kleen
2017-03-15 12:17 ` Sumit Saxena
2017-03-15 2:14 ` [PATCH 7/7] Remove expensive WARN_ON in pagefault_disabled_dec Andi Kleen
2017-03-15 21:49 ` Andrew Morton
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