Subject: [RFCv5 3/9] mm: cma: Added SysFS support

From: [email-masked] (Michał Nazarewicz)
Date: Tue, 07 Sep 2010 07:31:30 +0200

Hello Greg,

Thanks for reviewing the sysfs part.  Actually, I was never really sure
if I shouldn't rather put this code to debugfs and you got me convinced
that I should.  Sysfs somehow looked more appealing from kernel's API
point of view -- things seem to be more organised in sysfs than in
debugfs.  It seems I'll have to port it to debugfs after all

Nonetheless, a few responses to your comments:

> On Mon, Sep 06, 2010 at 08:33:53AM +0200, Michal Nazarewicz wrote:
>> +		The "allocators" file list all registered allocators.
>> +		Allocators with no name are listed as a single minus
>> +		sign.

On Mon, 06 Sep 2010 23:07:47 +0200, Greg KH <[email-masked]> wrote:
> So this returns more than one value?

Aren't thing like cpufreq governors listed in a single sysfs file?
I remember there was such a file somewhere.  Has that been made
deprecated? I cannot seem to find any information on that.

>> +		The "regions" directory list all reserved regions.
>
> Same here?

regions is actually a directory with subdirectories for each
region. ;)

>> +static ssize_t cma_sysfs_region_name_show(struct cma_region *reg, char *page)
>> +{
>> +	return reg->name ? snprintf(page, PAGE_SIZE, "%s\n", reg->name) : 0;
>> +}

> Is a name field ever really going to be bigger than a page?

I prefer being on the safe side -- I have no idea what user will provide
as region name so I assume as little as possible.  For numeric values you
are right that snprintf() is a bit paranoid, still I see no good reason
why not to use it.

-- 
Best regards,                                        _     _
| Humble Liege of Serenely Enlightened Majesty of  o' \,=./ `o
| Computer Science,  Micha? "mina86" Nazarewicz       (o o)
+----[mina86*mina86.com]---[mina86*jabber.org]----ooO--(_)--Ooo--