linux-kernel - Re: [PATCH v2 1/1] mmc: block: Add write packing control

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87629qkvgp.fsf@octavius.laptop.org>
Date:	Sat, 14 Jul 2012 15:12:54 -0400
From:	Chris Ball <cjb@...top.org>
To:	Muthu Kumar <muthu.lkml@...il.com>
Cc:	merez@...eaurora.org, linux-mmc@...r.kernel.org,
	linux-arm-msm@...r.kernel.org,
	DOCUMENTATION <linux-doc@...r.kernel.org>,
	open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 1/1] mmc: block: Add write packing control

Hi,

On Wed, Jun 13 2012, Muthu Kumar wrote:
> On Wed, Jun 13, 2012 at 12:52 PM,  <merez@...eaurora.org> wrote:
>>
>> On Mon, June 11, 2012 5:28 pm, Muthu Kumar wrote:
>>> On Mon, Jun 11, 2012 at 2:19 PM, Muthu Kumar <muthu.lkml@...il.com> wrote:
>>>> On Fri, Jun 1, 2012 at 11:55 AM, Maya Erez <merez@...eaurora.org> wrote:
>>>>> trigger
>>>>> the packing can be configured via sysfs by writing the required value
>>>>> to:
>>>>> /sys/block/<block_dev_name>/num_wr_reqs_to_start_packing.
>>>>> The trigger for disabling the write packing is fetching a read request.
>>>>>
>>>>
>>>> If it is applicable only to MMC why do we have this sysfs attr for all
>>>> block devices?
>>>
>>> Just to be clear, please create a directory, say mmc, under
>>> /sys/block/<dev>/ and create the attr inside that.
>>>
>>> You can refer to dm (dm-sysfs.c) for sample implementation.
>> I understand why you think it would be best to distinguish the MMC
>> specific attribute from the general block devices attributes.
>> However, since this attribute is created only for the MMC block device,
>> other block devices won't be aware of it.
>
> I understand its created by the MMC code so will not be there for
> other block devices. But having the device specific attributes inside
> one <device> directory is better/cleaner. And since we are already
> following that model for other devices, why not follow that for MMC
> also?

I've already replied to a later version of the patch, but just to get
this comment in at the appropriate point of the discussion as well:

Even though it would result in a cleaner sysfs, I don't want to do
this now because it will break userspace scripts that are depending
on the current locations of these attributes.

Thanks,

- Chris.
-- 
Chris Ball   <cjb@...top.org>   <http://printf.net/>
One Laptop Per Child
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/