The patch titled
Subject: include/linux/uaccess.h: remove expensive WARN_ON in pagefault_disabled_dec
has been added to the -mm tree. Its filename is
remove-expensive-warn_on-in-pagefault_disabled_dec.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/remove-expensive-warn_on-in-pagefault_disabled_dec.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/remove-expensive-warn_on-in-pagefault_disabled_dec.patch
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------------------------------------------------------
From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Subject: 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@xxxxxxxxxxxxxx
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/uaccess.h | 1 -
1 file changed, 1 deletion(-)
diff -puN include/linux/uaccess.h~remove-expensive-warn_on-in-pagefault_disabled_dec include/linux/uaccess.h
--- a/include/linux/uaccess.h~remove-expensive-warn_on-in-pagefault_disabled_dec
+++ a/include/linux/uaccess.h
@@ -12,7 +12,6 @@ static __always_inline void pagefault_di
static __always_inline void pagefault_disabled_dec(void)
{
current->pagefault_disabled--;
- WARN_ON(current->pagefault_disabled < 0);
}
/*
_
Patches currently in -mm which might be from ak@xxxxxxxxxxxxxxx are
trace-move-trace_seq_overflowed-out-of-line.patch
sched-out-of-line-__update_load_avg.patch
kref-remove-warn_on-for-null-release-functions.patch
out-of-line-dma_alloc-free_attrs.patch
megasas-remove-expensive-inline-from-megasas_return_cmd.patch
remove-expensive-warn_on-in-pagefault_disabled_dec.patch
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