diff options
Diffstat (limited to 'meta-moblin/packages/linux/linux-moblin-2.6.33.2/linux-2.6.34-ondemand-fix-7-7.patch')
| -rw-r--r-- | meta-moblin/packages/linux/linux-moblin-2.6.33.2/linux-2.6.34-ondemand-fix-7-7.patch | 114 |
1 files changed, 0 insertions, 114 deletions
diff --git a/meta-moblin/packages/linux/linux-moblin-2.6.33.2/linux-2.6.34-ondemand-fix-7-7.patch b/meta-moblin/packages/linux/linux-moblin-2.6.33.2/linux-2.6.34-ondemand-fix-7-7.patch deleted file mode 100644 index 32a2bdbb5..000000000 --- a/meta-moblin/packages/linux/linux-moblin-2.6.33.2/linux-2.6.34-ondemand-fix-7-7.patch +++ /dev/null @@ -1,114 +0,0 @@ ->From 27966bedabea83c4f3ae77507eceb746b1f6ebae Mon Sep 17 00:00:00 2001 -From: Arjan van de Ven <arjan@linux.intel.com> -Date: Sun, 18 Apr 2010 11:15:56 -0700 -Subject: [PATCH 7/7] ondemand: Solve the big performance issue with ondemand during disk IO -Patch-mainline: in -mm tree as of 19 Apr 2010 - -The ondemand cpufreq governor uses CPU busy time (e.g. not-idle time) as -a measure for scaling the CPU frequency up or down. -If the CPU is busy, the CPU frequency scales up, if it's idle, the CPU -frequency scales down. Effectively, it uses the CPU busy time as proxy -variable for the more nebulous "how critical is performance right now" -question. - -This algorithm falls flat on its face in the light of workloads where -you're alternatingly disk and CPU bound, such as the ever popular -"git grep", but also things like startup of programs and maildir using -email clients... much to the chagarin of Andrew Morton. - -This patch changes the ondemand algorithm to count iowait time as busy, -not idle, time. As shown in the breakdown cases above, iowait is performance -critical often, and by counting iowait, the proxy variable becomes a more -accurate representation of the "how critical is performance" question. - -The problem and fix are both verified with the "perf timechar" tool. - -Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> ---- - drivers/cpufreq/cpufreq_ondemand.c | 30 ++++++++++++++++++++++++++++-- - 1 files changed, 28 insertions(+), 2 deletions(-) - -diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c -index bd444dc..ed472f8 100644 ---- a/drivers/cpufreq/cpufreq_ondemand.c -+++ b/drivers/cpufreq/cpufreq_ondemand.c -@@ -73,6 +73,7 @@ enum {DBS_NORMAL_SAMPLE, DBS_SUB_SAMPLE}; - - struct cpu_dbs_info_s { - cputime64_t prev_cpu_idle; -+ cputime64_t prev_cpu_iowait; - cputime64_t prev_cpu_wall; - cputime64_t prev_cpu_nice; - struct cpufreq_policy *cur_policy; -@@ -148,6 +149,16 @@ static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall) - return idle_time; - } - -+static inline cputime64_t get_cpu_iowait_time(unsigned int cpu, cputime64_t *wall) -+{ -+ u64 iowait_time = get_cpu_iowait_time_us(cpu, wall); -+ -+ if (iowait_time == -1ULL) -+ return 0; -+ -+ return iowait_time; -+} -+ - /* - * Find right freq to be set now with powersave_bias on. - * Returns the freq_hi to be used right now and will set freq_hi_jiffies, -@@ -470,14 +481,15 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) - - for_each_cpu(j, policy->cpus) { - struct cpu_dbs_info_s *j_dbs_info; -- cputime64_t cur_wall_time, cur_idle_time; -- unsigned int idle_time, wall_time; -+ cputime64_t cur_wall_time, cur_idle_time, cur_iowait_time; -+ unsigned int idle_time, wall_time, iowait_time; - unsigned int load, load_freq; - int freq_avg; - - j_dbs_info = &per_cpu(od_cpu_dbs_info, j); - - cur_idle_time = get_cpu_idle_time(j, &cur_wall_time); -+ cur_iowait_time = get_cpu_iowait_time(j, &cur_wall_time); - - wall_time = (unsigned int) cputime64_sub(cur_wall_time, - j_dbs_info->prev_cpu_wall); -@@ -487,6 +499,10 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) - j_dbs_info->prev_cpu_idle); - j_dbs_info->prev_cpu_idle = cur_idle_time; - -+ iowait_time = (unsigned int) cputime64_sub(cur_iowait_time, -+ j_dbs_info->prev_cpu_iowait); -+ j_dbs_info->prev_cpu_iowait = cur_iowait_time; -+ - if (dbs_tuners_ins.ignore_nice) { - cputime64_t cur_nice; - unsigned long cur_nice_jiffies; -@@ -504,6 +520,16 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) - idle_time += jiffies_to_usecs(cur_nice_jiffies); - } - -+ /* -+ * For the purpose of ondemand, waiting for disk IO is an -+ * indication that you're performance critical, and not that -+ * the system is actually idle. So subtract the iowait time -+ * from the cpu idle time. -+ */ -+ -+ if (idle_time >= iowait_time) -+ idle_time -= iowait_time; -+ - if (unlikely(!wall_time || wall_time < idle_time)) - continue; - --- -1.6.2.5 - --- -To unsubscribe from this list: send the line "unsubscribe linux-kernel" in -the body of a message to majordomo@vger.kernel.org -More majordomo info at http://vger.kernel.org/majordomo-info.html -Please read the FAQ at http://www.tux.org/lkml/ - |