Re: x86: memtest bootparam

["Yinghai Lu" <yhlu.kernel@gmail.com>]

On Fri, Apr 18, 2008 at 4:32 PM, Andrew Morton
<akpm@linux-foundation.org> wrote:
> On Fri, 18 Apr 2008 15:07:46 -0700
>  "Yinghai Lu" <yhlu.kernel@gmail.com> wrote:
>
>  > On Fri, Apr 18, 2008 at 2:52 PM, Andrew Morton
>  > <akpm@linux-foundation.org> wrote:
>  > > On Fri, 18 Apr 2008 17:17:44 GMT
>  > >  Linux Kernel Mailing List <linux-kernel@vger.kernel.org> wrote:
>  > >
>  > >  > Gitweb:     http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=c64df70793a9c344874eb4af19f85e0662d2d3ee
>  > >  > Commit:     c64df70793a9c344874eb4af19f85e0662d2d3ee
>  > >  > Parent:     9b967106da0357ef8b08847dce35584a04134f20
>  > >  > Author:     Yinghai Lu <yhlu.kernel.send@gmail.com>
>  > >  > AuthorDate: Fri Mar 21 18:56:19 2008 -0700
>  > >  > Committer:  Ingo Molnar <mingo@elte.hu>
>  > >  > CommitDate: Thu Apr 17 17:41:21 2008 +0200
>  > >  >
>  > >  >     x86: memtest bootparam
>  > >  >
>  > >  > ...
>  > >  >
>  > >  >
>  > >  > +     memtest=        [KNL,X86_64] Enable memtest
>  > >  > +                     Format: <integer>
>  > >  > +                     range: 0,4 : pattern number
>  > >  > +                     default : 0 <disable>
>  > >
>  > >  OK.  Did the new memtest feature get documented anywhere, btw?  I'm only
>  > >  vaguely aware of its existence.
>  >
>  > need one text file in Documentation ?
>
>  Well if there was a single CONFIG_MEMTEST then it would probably be
>  sufficent to document it all within the Kconfig help for that option.
>
>  But there isn't a CONFIG_MEMTEST.  It appears that the presence or absence
>  of the memtest feature is controlled by CONFIG_MEMTEST_BOOTPARAM which
>  makes no sense at all!
>
>
>  > >  These seem pointless.  Why not just unconditionally implement memtest=?
>  > >  All the code for that should be __init anyway so we're hardly saving
>  > >  anything here.
>  >
>  > also
>  > for big box, like 64g above, that will take a while.
>
>  So... such users shouldn't add the memtest= boot parameter?
>
>
>  I'd suggest the following:
>
>  - Add a CONFIG_MEMTEST.  No other config variable needed.
>
>  - Put all the memtest code inside #ifdef CONFIG_MEMTEST.
>
>  - As part of that memtest code, implement the memtest= boot option
>
>  - Make the memtest feature default to "off" if memtest= was not provided.
>
>
>  That's all very simple and conventional?

ok, I will produce one patch. it will be

memtest=0 ==> disable
memtest=4 ==> will run 4 test pattern

YH