Fix performance regression on lmbench select benchmark

Christian Borntraeger reported that reinstating cond_resched() with
CONFIG_PREEMPT caused a performance regression on lmbench:

	For example select file 500:
	23 microseconds
	32 microseconds

and that's really because we totally unnecessarily do the cond_resched()
in the innermost loop of select(), which is just silly.

This moves it out from the innermost loop (which only ever loops ove the
bits in a single "unsigned long" anyway), which makes the performance
regression go away.

Reported-and-tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/select.c b/fs/select.c
index 8dda969614a9..da0e88201c3a 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -249,7 +249,6 @@ int do_select(int n, fd_set_bits *fds, s64 *timeout)
                                                 retval++;
                                         }
                                 }
-                                cond_resched();
                         }
                         if (res_in)
                                 *rinp = res_in;
@@ -257,6 +256,7 @@ int do_select(int n, fd_set_bits *fds, s64 *timeout)
                                 *routp = res_out;
                         if (res_ex)
                                 *rexp = res_ex;
+                        cond_resched();
                 }
                 wait = NULL;
                 if (retval || !*timeout || signal_pending(current))