Messages in this thread |  | | | Date | Fri, 8 Oct 2010 12:09:44 +0200 | | From | Andi Kleen <> | | Subject | Re: [PATCH 15/18] fs: introduce a per-cpu last_ino allocator |
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On Fri, Oct 08, 2010 at 10:58:24AM +0100, Al Viro wrote: > On Fri, Oct 08, 2010 at 10:22:34AM +0200, Andi Kleen wrote: > > Dave Chinner <david@fromorbit.com> writes: > > > > > From: Eric Dumazet <eric.dumazet@gmail.com> > > > > > > new_inode() dirties a contended cache line to get increasing > > > inode numbers. This limits performance on workloads that cause > > > significant parallel inode allocation. > > > > > > Solve this problem by using a per_cpu variable fed by the shared > > > last_ino in batches of 1024 allocations. This reduces contention on > > > the shared last_ino, and give same spreading ino numbers than before > > > (i.e. same wraparound after 2^32 allocations). > > > > This doesn't help for Unix disk file systems, so not fully sure why you > > need it for XFS. > > > > But looks reasonable, although it would be better to simply fix > > sockets/pipes/etc. to not allocate an inode numbers. > > Can be done if you bother to add ->getattr() for those, but you'll need > to do some kind of lazy allocation of inumbers for those; fstat() _will_ > want st_ino.
Why not just put 0 in st_ino for sockets/pipes/etc. ?
-Andi -- ak@linux.intel.com -- Speaking for myself only.
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