Re: 2.6.21-rc5-mm1

Andrew Morton
2007-03-27T21:41:05Z

On Tue, 27 Mar 2007 23:29:34 +0200
Eric Dumazet <dada1@cosmosbay.com> wrote:

> Andrew Morton a écrit :
> >
> > The wheel spins around, slows then settles on....
> > time-smp-friendly-alignment-of-struct-clocksource.patch!
> >
> > Presumably because the ____cacheline_aligned made vsyscall_gtod_data_t get
> > too big. Or something.
>
> Very strange, since here I have plenty of available room (256 bytes) :
>
> ffffffffff600000 T vgettimeofday
> ffffffffff60004e t vsysc2
> ffffffffff600140 t vread_hpet
> ffffffffff600150 t vread_tsc
> ffffffffff600180 D __vsyscall_gtod_data
> ffffffffff600280 D __vgetcpu_mode
> ffffffffff6002c0 D __jiffies
> <lot of space (256 bytes)>
> ffffffffff600400 T vtime
> ffffffffff600413 t vsysc1
> ffffffffff600800 T vgetcpu
> ffffffffff600c00 T venosys_1
>
> It must depends on the compiler, and/or CONFIG_XXX options...

Badari's config triggered it for me.

> Anyway, I think we can safely move __vgetcpu_mode & __jiffies to the 1024
> bytes area dedicated to vgetcpu() implementation. This saves 128 bytes from
> vsyscall_0 area.
>
> Could we add this patch instead of dropping
> time-smp-friendly-alignment-of-struct-clocksource.patch ?

When you tell me it works OK with Badari's config ;)