Re: gcc inlining heuristics was Re: [PATCH -v7][RFC]: mutex: implement adaptive spinning

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, 2009-01-20 at 13:38 +0100, Ingo Molnar wrote:
> 
> * Nick Piggin <npiggin@xxxxxxx> wrote:
> 
> > > > it seems like a nice opt-in thing that can be used where the aliases 
> > > > are verified and the code is particularly performance critical...
> > > 
> > > Yes. I think we could use it in the kernel, although I'm not sure how 
> > > many cases we would ever find where we really care.
> > 
> > Yeah, we don't tend to do a lot of intensive data processing, so it is 
> > normally the cache misses that hurt most as you noted earlier.
> > 
> > Some places it might be appropriate, though. It might be nice if it can 
> > bring code size down too...
> 
> I checked, its size effects were miniscule [0.17%] on the x86 defconfig 
> kernel and it seems to be a clear loss in total cost as there would be an 
> ongoing maintenance cost

They were talking about 'restrict', not strict-aliasing. Where it can be
used, it's going to give you optimisations that strict-aliasing can't.

-- 
David Woodhouse                            Open Source Technology Centre
David.Woodhouse@xxxxxxxxx                              Intel Corporation

--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux