Re: [PATCH 2/2] mke2fs: Enable lazy_itable_init on newer kernel by default

["Lukáš Czerner" <lczerner@redhat.com>]

On Mon, 24 Feb 2014, Eric Sandeen wrote:

> Date: Mon, 24 Feb 2014 11:43:21 -0600
> From: Eric Sandeen <sandeen@redhat.com>
> To: Lukas Czerner <lczerner@redhat.com>, linux-ext4@vger.kernel.org
> Cc: tytso@mit.edu
> Subject: Re: [PATCH 2/2] mke2fs: Enable lazy_itable_init on newer kernel by
>     default
> 
> On 2/24/14, 11:41 AM, Lukas Czerner wrote:
> > Currently is used did not specified lazy_itable_init option we rely on
> 
> s/is used did not specified/if user did not specify/ :)
> 
> > information from ext4 module exported via sysfs interface. However if
> > the ext4 module is not loaded it will not be enabled even though kernel
> > might support it.
> > 
> > With this commit we set the default according to the kernel version,
> > however we still allow it to be set manually via extended option or be
> > enabled in case that ext4 module advertise that it supports this
> > feature.
> > 
> > Signed-off-by: Lukas Czerner <lczerner@redhat.com>
> 
> Thanks,
> Reviewed-by: Eric Sandeen <sandeen@redhat.com>

Hi Ted,

are you planning to take this in ?

Thanks!
-Lukas

> 
> > ---
> >  misc/mke2fs.c | 10 +++++++++-
> >  1 file changed, 9 insertions(+), 1 deletion(-)
> > 
> > diff --git a/misc/mke2fs.c b/misc/mke2fs.c
> > index 957b4b6..e1c6d09 100644
> > --- a/misc/mke2fs.c
> > +++ b/misc/mke2fs.c
> > @@ -2146,7 +2146,15 @@ profile_error:
> >  			blocksize, sys_page_size);
> >  	}
> >  
> > -	lazy_itable_init = 0;
> > +	/*
> > +	 * On newer kernels we do have lazy_itable_init support. So pick the
> > +	 * right default in case ext4 module is not loaded.
> > +	 */
> > +	if (is_before_linux_ver(2, 6, 37))
> > +		lazy_itable_init = 0;
> > +	else
> > +		lazy_itable_init = 1;
> > +
> >  	if (access("/sys/fs/ext4/features/lazy_itable_init", R_OK) == 0)
> >  		lazy_itable_init = 1;
> >  
> > 
> 
>