From e25fa4faf5b4977cc90c87003a41107a920bbe4d Mon Sep 17 00:00:00 2001 From: Alan Jenkins Date: Sat, 25 Oct 2008 17:01:21 +0100 Subject: [PATCH] udevd: use a tighter loop for compare_devpath() This crops up in my threaded udevd profiles from time to time. It's not consistent - probably due to variations in the number of concurrent events - but it can hit 4% user time and higher. The change halves the user time spent in compare_devpath(). Signed-off-by: Alan Jenkins --- udev/udevd.c | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) diff --git a/udev/udevd.c b/udev/udevd.c index 21fd6f82..0bacb399 100644 --- a/udev/udevd.c +++ b/udev/udevd.c @@ -310,26 +310,24 @@ static int mem_size_mb(void) static int compare_devpath(const char *running, const char *waiting) { - int i; + int i = 0; - for (i = 0; i < UTIL_PATH_SIZE; i++) { - /* identical device event found */ - if (running[i] == '\0' && waiting[i] == '\0') - return 1; + while (running[i] == waiting[i] && running[i] != '\0') + i++; - /* parent device event found */ - if (running[i] == '\0' && waiting[i] == '/') - return 2; + /* identical device event found */ + if (running[i] == '\0' && waiting[i] == '\0') + return 1; - /* child device event found */ - if (running[i] == '/' && waiting[i] == '\0') - return 3; + /* parent device event found */ + if (running[i] == '\0' && waiting[i] == '/') + return 2; - /* no matching event */ - if (running[i] != waiting[i]) - break; - } + /* child device event found */ + if (running[i] == '/' && waiting[i] == '\0') + return 3; + /* no matching event */ return 0; } -- 2.39.5