lkml.org 
[lkml]   [2015]   [Jan]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v1 2/2] zram: remove init_lock in zram_make_request
On Thu, Jan 29, 2015 at 11:22:41AM +0900, Sergey Senozhatsky wrote:
> On (01/29/15 11:01), Minchan Kim wrote:
> > On Thu, Jan 29, 2015 at 10:57:38AM +0900, Sergey Senozhatsky wrote:
> > > On Thu, Jan 29, 2015 at 8:33 AM, Minchan Kim <minchan@kernel.org> wrote:
> > > > On Wed, Jan 28, 2015 at 11:56:51PM +0900, Sergey Senozhatsky wrote:
> > > > > I don't like re-introduced ->init_done.
> > > > > another idea... how about using `zram->disksize == 0' instead of
> > > > > `->init_done' (previously `->meta != NULL')? should do the trick.
> > > >
> > > > It could be.
> > > >
> > > >
> > > care to change it?
> >
> > Will try!
> >
> > If it was your concern, I'm happy to remove the check.(ie, actually,
> > I realized that after I push the button to send). Thanks!
> >
>
> Thanks a lot, Minchan.
>
> and, guys, sorry for previous html email (I'm sure I toggled the "plain
> text" mode in gmail web-interface, but somehow it has different meaning
> in gmail world).
>
>
> I'm still concerned about performance numbers that I see on my x86_64.
> it's not always, but mostly slower. I'll give it another try (disable
> lockdep, etc.), but if we lose 10% on average then, sorry, I'm not so
> positive about srcu change and will tend to vote for your initial commit
> that simply moved meta free() out of init_lock and left locking as is
> (lockdep warning would have been helpful there, because otherwise it
> just looked like we change code w/o any reason).
>
> what do you thunk?

Surely I agreee with you. If it suffers from 10% performance regression,
it's absolutely no go.

However, I believe it should be no loss because that's one of the reason
from RCU birth which should be really win in read-side lock path compared
to other locking.

Please test it with dd or something for block-based test for removing
noise from FS. I also will test it to confirm that with real machine.

Thanks for the review!



>
> -ss

--
Kind regards,
Minchan Kim


\
 
 \ /
  Last update: 2015-01-29 06:41    [W:0.105 / U:0.144 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site