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From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Arnd Bergmann <arnd@kernel.org>
Cc: Hyun Kwon <hyun.kwon@xilinx.com>, Vinod Koul <vkoul@kernel.org>,
	Michal Simek <michal.simek@xilinx.com>,
	Sanjay R Mehta <sanju.mehta@amd.com>,
	Peter Ujfalusi <peter.ujfalusi@ti.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Jianqiang Chen <jianqiang.chen@xilinx.com>,
	Quanyang Wang <quanyang.wang@windriver.com>,
	Yang Li <yang.lee@linux.alibaba.com>,
	Allen Pais <apais@linux.microsoft.com>,
	Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>,
	Biju Das <biju.das.jz@bp.renesas.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	dmaengine@vger.kernel.org,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] dmaengine: remove debugfs #ifdef
Date: Mon, 20 Sep 2021 19:28:01 +0300	[thread overview]
Message-ID: <YUi2kQqNVLSeA87X@pendragon.ideasonboard.com> (raw)
In-Reply-To: <CAK8P3a1fcmCWsOuqF8qy4ko9MC8nCd4gyt2K6Rk5K-Zs7yCbJA@mail.gmail.com>

Hi Arnd,

On Mon, Sep 20, 2021 at 02:50:52PM +0200, Arnd Bergmann wrote:
> On Mon, Sep 20, 2021 at 2:47 PM Laurent Pinchart wrote:
> >
> > It's only a few bytes of data in struct dma_device, but a bit more in
> > .text here. Is the simplification really required in this driver ?
> 
> The intention was to not change the resulting object code in this driver,
> and I still don't see where it would grow after dead-code-elimination removes
> all the unused static functions. What am I missing?

Indeed, gcc does a fairly good job there. The .text section doesn't
grow. Interestingly, there's an increase in size in the .data and
.rodata sections in the xilinx-dpdma module:

-  8 .rodata.str1.8 0000029f  0000000000000000  0000000000000000  00003660  2**3
+  8 .rodata.str1.8 000002a7  0000000000000000  0000000000000000  00003660  2**3

- 10 .rodata       00001080  0000000000000000  0000000000000000  00003960  2**5
+ 10 .rodata       000010e0  0000000000000000  0000000000000000  00003960  2**5

- 15 .data         00001050  0000000000000000  0000000000000000  00004e40  2**5
+ 15 .data         00001090  0000000000000000  0000000000000000  00004ea0  2**5

I'm not entirely sure where it comes from, it may be related to
instrumentation caused by debugging options.

For your patch,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

-- 
Regards,

Laurent Pinchart

WARNING: multiple messages have this Message-ID (diff)
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Arnd Bergmann <arnd@kernel.org>
Cc: Hyun Kwon <hyun.kwon@xilinx.com>, Vinod Koul <vkoul@kernel.org>,
	Michal Simek <michal.simek@xilinx.com>,
	Sanjay R Mehta <sanju.mehta@amd.com>,
	Peter Ujfalusi <peter.ujfalusi@ti.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Jianqiang Chen <jianqiang.chen@xilinx.com>,
	Quanyang Wang <quanyang.wang@windriver.com>,
	Yang Li <yang.lee@linux.alibaba.com>,
	Allen Pais <apais@linux.microsoft.com>,
	Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>,
	Biju Das <biju.das.jz@bp.renesas.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	dmaengine@vger.kernel.org,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] dmaengine: remove debugfs #ifdef
Date: Mon, 20 Sep 2021 19:28:01 +0300	[thread overview]
Message-ID: <YUi2kQqNVLSeA87X@pendragon.ideasonboard.com> (raw)
In-Reply-To: <CAK8P3a1fcmCWsOuqF8qy4ko9MC8nCd4gyt2K6Rk5K-Zs7yCbJA@mail.gmail.com>

Hi Arnd,

On Mon, Sep 20, 2021 at 02:50:52PM +0200, Arnd Bergmann wrote:
> On Mon, Sep 20, 2021 at 2:47 PM Laurent Pinchart wrote:
> >
> > It's only a few bytes of data in struct dma_device, but a bit more in
> > .text here. Is the simplification really required in this driver ?
> 
> The intention was to not change the resulting object code in this driver,
> and I still don't see where it would grow after dead-code-elimination removes
> all the unused static functions. What am I missing?

Indeed, gcc does a fairly good job there. The .text section doesn't
grow. Interestingly, there's an increase in size in the .data and
.rodata sections in the xilinx-dpdma module:

-  8 .rodata.str1.8 0000029f  0000000000000000  0000000000000000  00003660  2**3
+  8 .rodata.str1.8 000002a7  0000000000000000  0000000000000000  00003660  2**3

- 10 .rodata       00001080  0000000000000000  0000000000000000  00003960  2**5
+ 10 .rodata       000010e0  0000000000000000  0000000000000000  00003960  2**5

- 15 .data         00001050  0000000000000000  0000000000000000  00004e40  2**5
+ 15 .data         00001090  0000000000000000  0000000000000000  00004ea0  2**5

I'm not entirely sure where it comes from, it may be related to
instrumentation caused by debugging options.

For your patch,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

-- 
Regards,

Laurent Pinchart

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2021-09-20 16:28 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-20 12:20 [PATCH] dmaengine: remove debugfs #ifdef Arnd Bergmann
2021-09-20 12:20 ` Arnd Bergmann
2021-09-20 12:47 ` Laurent Pinchart
2021-09-20 12:47   ` Laurent Pinchart
2021-09-20 12:50   ` Arnd Bergmann
2021-09-20 12:50     ` Arnd Bergmann
2021-09-20 16:28     ` Laurent Pinchart [this message]
2021-09-20 16:28       ` Laurent Pinchart
2021-10-25  6:31 ` Vinod Koul
2021-10-25  6:31   ` Vinod Koul

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