Re: [PATCH 17/18] fs: icache remove inode_lock

Eric Dumazet
2010-10-13T10:42:45Z

Le mercredi 13 octobre 2010 à 18:20 +1100, Nick Piggin a écrit :

> I don't think the patchset has suddenly become vastly more urgent
> in the past month, so I think my approach of having it get a lot
> of testing and go in Al's vfs tree for a while is best.
>

Hi Nick

Not vastly urgent, but highly wanted on many workloads, even ones not
really related to 'fs'...

In current tree, a "close(socket())" needs 31 us on a 2x4x2 machine,
instead of 1.45 us if single thread.

But yes, I agree a lot of testing is needed :)

--------------------------------------------------------------------------------------------
PerfTop: 16584 irqs/sec kernel:99.8% exact: 0.0% [1000Hz cycles], (all, 16 CPUs)
--------------------------------------------------------------------------------------------

samples pcnt function DSO
_______ _____ ________________________ _______

101217.00 87.8% _raw_spin_lock vmlinux
1365.00 1.2% kmem_cache_alloc vmlinux
1220.00 1.1% d_alloc vmlinux
1159.00 1.0% sock_alloc_file vmlinux
881.00 0.8% __d_instantiate vmlinux
657.00 0.6% memset vmlinux
516.00 0.4% dput vmlinux
423.00 0.4% new_inode vmlinux
401.00 0.3% _atomic_dec_and_lock vmlinux
397.00 0.3% iput vmlinux
358.00 0.3% dentry_iput vmlinux
320.00 0.3% kmem_cache_free vmlinux
309.00 0.3% __slab_free vmlinux
297.00 0.3% __sk_free vmlinux
264.00 0.2% kmem_cache_alloc_notrace vmlinux
263.00 0.2% __call_rcu vmlinux

Thanks