tree 6b867456be48b8633a2d56a99e00bb3faf9dccc7
parent 31e6b01f4183ff419a6d1f86177cbf4662347cec
author Nick Piggin <npiggin@kernel.dk> 1294382993 +1100
committer Nick Piggin <npiggin@kernel.dk> 1294383027 +1100

fs: fs_struct use seqlock

Use a seqlock in the fs_struct to enable us to take an atomic copy of the
complete cwd and root paths. Use this in the RCU lookup path to avoid a
thread-shared spinlock in RCU lookup operations.

Multi-threaded apps may now perform path lookups with scalability matching
multi-process apps. Operations such as stat(2) become very scalable for
multi-threaded workload.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>