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From: Thomas Gleixner <tglx@linutronix.de>
To: Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
	Frederic Weisbecker <frederic@kernel.org>,
	Jonathan Corbet <corbet@lwn.net>,
	Anna-Maria Behnsen <anna-maria@linutronix.de>
Cc: linux-kernel@vger.kernel.org, Len Brown <len.brown@intel.com>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Anna-Maria Behnsen <anna-maria@linutronix.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	damon@lists.linux.dev, linux-mm@kvack.org,
	SeongJae Park <sj@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
	linux-arch@vger.kernel.org,
	Heiner Kallweit <hkallweit1@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	Andy Whitcroft <apw@canonical.com>, Joe Perches <joe@perches.com>,
	Dwaipayan Ray <dwaipayanray1@gmail.com>,
	Liam Girdwood <lgirdwood@gmail.com>,
	Mark Brown <broonie@kernel.org>, Andrew Lunn <andrew@lunn.ch>,
	Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
	netdev@vger.kernel.org, linux-sound@vger.kernel.org,
	Michael Ellerman <mpe@ellerman.id.au>,
	Nathan Lynch <nathanl@linux.ibm.com>,
	linuxppc-dev@lists.ozlabs.org,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	linux-media@vger.kernel.org
Subject: Re: [PATCH v2 00/15] timers: Cleanup delay/sleep related mess
Date: Wed, 02 Oct 2024 17:02:00 +0200	[thread overview]
Message-ID: <87ttduwntj.ffs@tglx> (raw)
In-Reply-To: <c794b4a6-468d-4552-a6d6-8185f49339d3@wanadoo.fr>

On Mon, Sep 16 2024 at 22:20, Christophe JAILLET wrote:
> Le 11/09/2024 à 07:13, Anna-Maria Behnsen a écrit :
>
> not directly related to your serie, but some time ago I sent a patch to 
> micro-optimize Optimize usleep_range(). (See [1])
>
> The idea is that the 2 parameters of usleep_range() are usually 
> constants and some code reordering could easily let the compiler compute 
> a few things at compilation time.
>
> There was consensus on the value of the change (see [2]), but as you are 
> touching things here, maybe it makes sense now to save a few cycles at 
> runtime and a few bytes of code?

For the price of yet another ugly interface and pushing the
multiplication into the non-constant call sites.

Seriously usleep() is not a hotpath operation and the multiplication is
not even measurable except in micro benchmarks.

Thanks,

        tglx

      parent reply	other threads:[~2024-10-02 15:02 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-09-11  5:13 [PATCH v2 00/15] timers: Cleanup delay/sleep related mess Anna-Maria Behnsen
2024-09-11  5:13 ` [PATCH v2 05/15] timers: Update function descriptions of sleep/delay related functions Anna-Maria Behnsen
2024-10-06 21:49   ` Frederic Weisbecker
2024-10-10  8:45     ` Anna-Maria Behnsen
2024-10-10 12:36       ` Frederic Weisbecker
2024-10-11 10:20         ` Anna-Maria Behnsen
2024-10-11 12:22           ` Frederic Weisbecker
2024-09-16 20:20 ` [PATCH v2 00/15] timers: Cleanup delay/sleep related mess Christophe JAILLET
2024-09-17  5:22   ` Christophe JAILLET
2024-09-23 15:12     ` Anna-Maria Behnsen
2024-10-02 15:02   ` Thomas Gleixner [this message]

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