include/linux/uaccess.h: remove expensive WARN_ON in pagefault_disabled_dec

pagefault_disabled_dec is frequently used inline, and it has a WARN_ON
for underflow that expands to about 6.5k of extra code.  The warning
doesn't seem to be that useful and worth so much code so remove it.

If it was needed could make it depending on some debug kernel option.

Saves ~6.5k in my kernel

     text    data     bss     dec     hex filename
  9039417 5367568 11116544        25523529        1857549 vmlinux-before-pf
  9032805 5367568 11116544        25516917        1855b75 vmlinux-pf

Link: http://lkml.kernel.org/r/20170315021431.13107-8-andi@firstfloor.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index e0cbfb09e60f042d09b983ed596d309e1add654d..201418d5e15c2b92dc7d7bc73b54f469eb488a35 100644 (file)
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -203,7 +203,6 @@ static __always_inline void pagefault_disabled_inc(void)
 static __always_inline void pagefault_disabled_dec(void)
 {
        current->pagefault_disabled--;
-       WARN_ON(current->pagefault_disabled < 0);
 }
 
 /*