Re: [PATCH v2 3/3] vfs: Enable list batching for the superblock's inode list

[Waiman Long]

On 02/01/2016 12:45 PM, Andi Kleen wrote:
> > I'm wondering, why are inode_sb_list_add()/del() even called for a presumably
> > reasonably well cached benchmark running on a system with enough RAM? Are these
> > perhaps thousands of temporary files, already deleted, and released when all the
> > file descriptors are closed as part of sys_exit()?
> >
> > If that's the case then I suspect an even bigger win would be not just to batch
> > the (sb-)global list fiddling, but to potentially turn the sb list into a
> > percpu_alloc() managed set of per CPU lists? It's a bigger change, but it could
> We had such a patch in the lock elision patchkit (It avoided a lot
> of cache line bouncing leading to aborts)
>
> https://git.kernel.org/cgit/linux/kernel/git/ak/linux-misc.git/commit/?h=hle315/combined&id=f1cf9e715a40f44086662ae3b29f123cf059cbf4
>
> -Andi

I like your patch though it cannot be applied cleanly for the current 
upstream kernel. I will port it to the current kernel and run my 
microbenchmark to see what performance gain I can get.

Cheers,
Longman