[0/3] fs/file.c: optimize the critical section of

Message

Ma, Yu June 14, 2024, 4:34 p.m. UTC

pts/blogbench-1.1.0 is a benchmark designed to replicate the
load of a real-world busy file server by multiple threads of
random reads, writes, and rewrites. When running default configuration
with multiple parallel threads, hot spin lock contention is observed
from alloc_fd(), file_closed_fd() and put_unused_fd() around file_lock.

These 3 patches are created to reduce the critical section of file_lock
in alloc_fd() and close_fd(). As a result, pts/blogbench-1.1.0 has been
improved by 32% for read and 15% for write with over 30% kernel cycles
reduced on ICX 160 cores configuration with v6.8-rc6.

Yu Ma (3):
  fs/file.c: add fast path in alloc_fd()
  fs/file.c: conditionally clear full_fds
  fs/file.c: move sanity_check from alloc_fd() to put_unused_fd()

 fs/file.c | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)