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From: Levente Kurusa <levex@linux.com>
To: Tejun Heo <tj@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 21/38] workqueue: add missing put_device call
Date: Thu, 19 Dec 2013 16:31:36 +0100	[thread overview]
Message-ID: <52B31158.3030801@linux.com> (raw)
In-Reply-To: <20131219152044.GB16994@htj.dyndns.org>

On 12/19/2013 04:20 PM, Tejun Heo wrote:
> Umm... this doesn't look right.  You're basically converting the code
> to the following,
> 
> 	x = kmalloc();
> 	if (register(x) < 0)
> 		put(x)
> 
> They're not symmetrical anymore.  register(), or any API call really,
> isn't supposed to have side effects which need explicit cleanup after
> a failure.  The fact that x is properly initialized even after
> register(x) failed is a coincidental implementation detail which
> shouldn't be depended upon.  Your patch is actively breaking the
> convention for no good reason.
> 
>  Nacked-by: Tejun Heo <tj@kernel.org>
> 
>>From the patch title, I suppose you posted a bunch of patches towards
> this direction.  Please consider all of them nacked if they're doing
> the same thing.
> 
> Thanks.
> 

The reason I removed the kfree() was because the put_device() will decrement
wq_dev->dev's reference count to zero (it is set to one by device_register) and hence the
wq_device_release() will be called. Now, this effectively does the same the kfree() call
would have done but also driver core is notified.

Also, if you take a look at the comment for the device_register() function, it explicitly
says NOT to kfree the struct device, but instead call put_device() and let the device's release()
function take care.

-- 
Regards,
Levente Kurusa

  reply	other threads:[~2013-12-19 15:31 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-19 15:03 [PATCH 01/38] sh: dma-sysfs: add missing put_device call Levente Kurusa
2013-12-19 15:03 ` [PATCH 02/38] powerpc: qe_lib: " Levente Kurusa
2013-12-19 15:03 ` [PATCH 03/38] powerpc: cell: " Levente Kurusa
2013-12-19 15:03 ` [PATCH 04/38] powerpc: kernel: " Levente Kurusa
2013-12-19 15:03 ` [PATCH 05/38] sparc: " Levente Kurusa
2013-12-27 17:43   ` David Miller
2013-12-19 15:03 ` [PATCH 06/38] arm: mach-s3c64: " Levente Kurusa
2013-12-19 15:03 ` [PATCH 07/38] arm: locomo: " Levente Kurusa
2013-12-19 15:03 ` [PATCH 08/38] arm: mach-rpc: " Levente Kurusa
2013-12-19 15:03 ` [PATCH 09/38] arm: mach-imx: add missing put_device calls Levente Kurusa
2013-12-19 15:03 ` [PATCH 10/38] arm: exynos: add missing put_device call Levente Kurusa
2013-12-19 15:03 ` [PATCH 11/38] arm: mach-integrator: " Levente Kurusa
2013-12-19 15:03 ` [PATCH 12/38] arm: s5pv210: " Levente Kurusa
2013-12-19 15:03 ` [PATCH 13/38] arm: s390: " Levente Kurusa
2013-12-19 15:03 ` [PATCH 14/38] mips: txx9: " Levente Kurusa
2013-12-19 15:03 ` [PATCH 15/38] mips: txx9: 7segled: " Levente Kurusa
2013-12-19 15:03 ` [PATCH 16/38] mips: sgi-ip22: " Levente Kurusa
2013-12-19 15:03 ` [PATCH 17/38] parisc: kernel: " Levente Kurusa
2013-12-19 15:29   ` James Bottomley
2013-12-19 15:03 ` [PATCH 18/38] ia64: " Levente Kurusa
2013-12-19 15:03 ` [PATCH 19/38] net: atm: " Levente Kurusa
2013-12-27 17:40   ` David Miller
2013-12-19 15:03 ` [PATCH 20/38] net: iucv: " Levente Kurusa
2013-12-27 17:41   ` David Miller
2013-12-19 15:03 ` [PATCH 21/38] workqueue: " Levente Kurusa
2013-12-19 15:20   ` Tejun Heo
2013-12-19 15:31     ` Levente Kurusa [this message]
2013-12-19 15:34       ` Tejun Heo
2013-12-19 15:42         ` Levente Kurusa
2013-12-19 15:45           ` Tejun Heo
2013-12-19 15:03 ` [PATCH 22/38] sound: ac97: " Levente Kurusa
2013-12-19 16:17   ` Takashi Iwai
2013-12-19 15:03 ` [PATCH 23/38] sound: soc: " Levente Kurusa
2013-12-21 14:31   ` Mark Brown
2013-12-19 15:03 ` [PATCH 24/38] pcmcia: " Levente Kurusa
2013-12-19 15:03 ` [PATCH 25/38] pnp: card: " Levente Kurusa
2014-01-05 22:04   ` Rafael J. Wysocki
2013-12-19 15:03 ` [PATCH 26/38] xen: xenbus: " Levente Kurusa
2014-01-02 13:53   ` [Xen-devel] " David Vrabel
2014-01-06 10:00     ` Ian Campbell
2014-01-06 11:00       ` David Vrabel
2014-01-06 11:09         ` Ian Campbell
2013-12-19 15:03 ` [PATCH 27/38] superhyway: " Levente Kurusa
2013-12-19 15:03 ` [PATCH 28/38] superhyway: intc: " Levente Kurusa
2013-12-19 15:03 ` [PATCH 29/38] superhyway: maple: " Levente Kurusa
2013-12-19 15:03 ` [PATCH 30/38] vlynq: " Levente Kurusa
2013-12-19 17:37   ` Florian Fainelli

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