Attachment 663007 Details for Bug 886185 – Proposed fix sent upstream

[patch] Proposed fix sent upstream

0001-Reduced-number-of-useless-open-syscalls.patch (text/plain), 5.00 KB, created by Jaroslav Škarvada on 2012-12-13 14:45:26 UTC

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Creator: Jaroslav Škarvada

Created: 2012-12-13 14:45:26 UTC

Size: 5.00 KB

patch

obsolete

>From 63b20549280e606e5e73d5c9fe701c79a5abc6cf Mon Sep 17 00:00:00 2001
>From: =?UTF-8?q?Jaroslav=20=C5=A0karvada?= <jskarvad@redhat.com>
>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 Å karvada <jskarvad@redhat.com>
>---
> 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 <sys/types.h>
> #include <dirent.h>
> #include <string.h>
>+#include <ctype.h>
> 
> 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 <dirent.h>
> #include <errno.h>
> #include <sys/stat.h>
>+#include <ctype.h>
> 
> #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
>

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Attachments on bug 886185: 662423 | 663007 | 678277