From 63b20549280e606e5e73d5c9fe701c79a5abc6cf Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jaroslav=20=C5=A0karvada?= Date: Wed, 12 Dec 2012 16:19:56 +0100 Subject: [PATCH] Reduced number of useless 'open' syscalls MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There are called many useless 'open' syscalls that always fail, like: open("/sys/devices/system/cpu/uevent/cpufreq/scaling_governor", O_RDONLY) = -1 ENOTDIR (Not a directory) This patch filters them to 'likely' patterns, like e.g.: /sys/devices/system/cpu/cpuX/cpufreq/scaling_governor, where X is string starting with digit. For match cases it will add only small overhead. Originally reported as: https://bugzilla.redhat.com/show_bug.cgi?id=886185 Signed-off-by: Jaroslav Škarvada --- src/devices/alsa.cpp | 2 +- src/devices/backlight.cpp | 2 ++ src/devlist.cpp | 3 ++- src/tuning/cpufreq.cpp | 11 ++++++----- src/tuning/tuningsysfs.cpp | 5 +---- 5 files changed, 12 insertions(+), 11 deletions(-) diff --git a/src/devices/alsa.cpp b/src/devices/alsa.cpp index 4f5d3f9..33a52f5 100644 --- a/src/devices/alsa.cpp +++ b/src/devices/alsa.cpp @@ -167,7 +167,7 @@ void create_all_alsa(void) entry = readdir(dir); if (!entry) break; - if (entry->d_name[0] == '.') + if (strncmp(entry->d_name, "hwC", 3) != 0) continue; sprintf(filename, "/sys/class/sound/card0/%s/power_on_acct", entry->d_name); diff --git a/src/devices/backlight.cpp b/src/devices/backlight.cpp index b8c9147..03aa5bc 100644 --- a/src/devices/backlight.cpp +++ b/src/devices/backlight.cpp @@ -90,6 +90,8 @@ static int dpms_screen_on(void) if (!entry) break; + if (strncmp(entry->d_name, "card", 4) != 0) + continue; sprintf(filename, "/sys/class/drm/card0/%s/enabled", entry->d_name); file.open(filename, ios::in); if (!file) diff --git a/src/devlist.cpp b/src/devlist.cpp index de5abff..633a568 100644 --- a/src/devlist.cpp +++ b/src/devlist.cpp @@ -37,6 +37,7 @@ #include #include #include +#include using namespace std; @@ -117,7 +118,7 @@ void collect_open_devices(void) entry2 = readdir(dir2); if (!entry2) break; - if (entry2->d_name[0] == '.') + if (!isdigit(entry2->d_name[0])) continue; sprintf(filename, "/proc/%s/fd/%s", entry->d_name, entry2->d_name); memset(link, 0, 4096); diff --git a/src/tuning/cpufreq.cpp b/src/tuning/cpufreq.cpp index df245ad..e870559 100644 --- a/src/tuning/cpufreq.cpp +++ b/src/tuning/cpufreq.cpp @@ -36,6 +36,7 @@ #include #include #include +#include #include "../lib.h" #include "cpufreq.h" @@ -72,7 +73,7 @@ int cpufreq_tunable::good_bad(void) return ret; while ((dirent = readdir(dir))) { - if (dirent->d_name[0]=='.') + if (strncmp(dirent->d_name, "cpu", 3) != 0 || !isdigit(dirent->d_name[3])) continue; sprintf(filename, "/sys/devices/system/cpu/%s/cpufreq/scaling_governor", dirent->d_name); file = fopen(filename, "r"); @@ -123,7 +124,7 @@ void cpufreq_tunable::toggle(void) return; while ((dirent = readdir(dir))) { - if (dirent->d_name[0]=='.') + if (strncmp(dirent->d_name, "cpu", 3) != 0 || !isdigit(dirent->d_name[3])) continue; sprintf(filename, "/sys/devices/system/cpu/%s/cpufreq/scaling_governor", dirent->d_name); file = fopen(filename, "w"); @@ -141,7 +142,7 @@ void cpufreq_tunable::toggle(void) return; while ((dirent = readdir(dir))) { - if (dirent->d_name[0]=='.') + if (strncmp(dirent->d_name, "cpu", 3) != 0 || !isdigit(dirent->d_name[3])) continue; sprintf(filename, "/sys/devices/system/cpu/%s/cpufreq/scaling_governor", dirent->d_name); file = fopen(filename, "w"); @@ -171,7 +172,7 @@ const char *cpufreq_tunable::toggle_script(void) { return NULL; while ((dirent = readdir(dir))) { - if (dirent->d_name[0]=='.') + if (strncmp(dirent->d_name, "cpu", 3) != 0 || !isdigit(dirent->d_name[3])) continue; sprintf(filename, "/sys/devices/system/cpu/%s/cpufreq/scaling_governor", dirent->d_name); if (stat(filename, &statbuf) == -1) @@ -189,7 +190,7 @@ const char *cpufreq_tunable::toggle_script(void) { return NULL; while ((dirent = readdir(dir))) { - if (dirent->d_name[0]=='.') + if (strncmp(dirent->d_name, "cpu", 3) != 0 || !isdigit(dirent->d_name[3])) continue; sprintf(filename, "/sys/devices/system/cpu/%s/cpufreq/scaling_governor", dirent->d_name); if (stat(filename, &statbuf) == -1) diff --git a/src/tuning/tuningsysfs.cpp b/src/tuning/tuningsysfs.cpp index 33d3786..ec1ca6b 100644 --- a/src/tuning/tuningsysfs.cpp +++ b/src/tuning/tuningsysfs.cpp @@ -131,10 +131,7 @@ void add_sata_tunables(void) if (!entry) break; - if (strcmp(entry->d_name, ".") == 0) - continue; - - if (strcmp(entry->d_name, "..") == 0) + if (entry->d_name[0] == '.') continue; sprintf(filename, "/sys/class/scsi_host/%s/link_power_management_policy", entry->d_name); -- 1.7.11.7