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| author | David Gibson <david@gibson.dropbear.id.au> | 2005-11-08 21:34:46 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-09 07:55:53 -0800 |
| commit | 3f04e7ddf47a1c821dfaa886161d94774af583fa (patch) | |
| tree | dbe112747d7096ae0b8cbe900e2d19529970001e /scripts/kconfig/expr.h | |
| parent | cecd1ca0cbd6fc5873e9bb110dacb8411be72928 (diff) | |
| download | linux-3f04e7ddf47a1c821dfaa886161d94774af583fa.tar.gz linux-3f04e7ddf47a1c821dfaa886161d94774af583fa.tar.bz2 linux-3f04e7ddf47a1c821dfaa886161d94774af583fa.zip | |
[PATCH] kconfig: Fix Kconfig performance bug
When doing its recursive dependency check, scripts/kconfig/conf uses the flag
SYMBOL_CHECK_DONE to avoid rechecking a symbol it has already checked.
However, that flag is only set at the top level, so if a symbol is first
encountered as a dependency of another symbol it will be rechecked every time
it is encountered until it's encountered at the top level.
This patch adjusts the flag setting so that each symbol will only be checked
once, regardless of whether it is first encountered at the top level, or while
recursing down from another symbol. On complex configurations, this vastly
speeds up scripts/kconfig/conf. The config in the powerpc merge tree is
particularly bad: this patch reduces the time for 'scripts/kconfig/conf -o
arch/powerpc/Kconfig' by a factor of 40 on a G5. That's even including the
time to print the config, so the speedup in the actual checking is more likely
2 or 3 orders of magnitude.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'scripts/kconfig/expr.h')
| -rw-r--r-- | scripts/kconfig/expr.h | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/scripts/kconfig/expr.h b/scripts/kconfig/expr.h index 7d39ff43e6e1..1b36ef18c48d 100644 --- a/scripts/kconfig/expr.h +++ b/scripts/kconfig/expr.h @@ -93,7 +93,6 @@ struct symbol { #define SYMBOL_NEW 0x0800 #define SYMBOL_AUTO 0x1000 #define SYMBOL_CHECKED 0x2000 -#define SYMBOL_CHECK_DONE 0x4000 #define SYMBOL_WARNED 0x8000 #define SYMBOL_MAXLENGTH 256 |