From 3292beb340c76884427faa1f5d6085719477d889 Mon Sep 17 00:00:00 2001 From: Glauber Costa Date: Mon, 28 Nov 2011 14:45:17 -0200 Subject: sched/accounting: Change cpustat fields to an array This patch changes fields in cpustat from a structure, to an u64 array. Math gets easier, and the code is more flexible. Signed-off-by: Glauber Costa Reviewed-by: KAMEZAWA Hiroyuki Cc: Linus Torvalds Cc: Andrew Morton Cc: Paul Tuner Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1322498719-2255-2-git-send-email-glommer@parallels.com Signed-off-by: Ingo Molnar --- fs/proc/stat.c | 63 +++++++++++++++++++++++++++------------------------------- 1 file changed, 29 insertions(+), 34 deletions(-) (limited to 'fs/proc/stat.c') diff --git a/fs/proc/stat.c b/fs/proc/stat.c index 42b274da92c3..8a6ab666e9f8 100644 --- a/fs/proc/stat.c +++ b/fs/proc/stat.c @@ -22,29 +22,27 @@ #define arch_idle_time(cpu) 0 #endif -static cputime64_t get_idle_time(int cpu) +static u64 get_idle_time(int cpu) { - u64 idle_time = get_cpu_idle_time_us(cpu, NULL); - cputime64_t idle; + u64 idle, idle_time = get_cpu_idle_time_us(cpu, NULL); if (idle_time == -1ULL) { /* !NO_HZ so we can rely on cpustat.idle */ - idle = kstat_cpu(cpu).cpustat.idle; - idle = cputime64_add(idle, arch_idle_time(cpu)); + idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE]; + idle += arch_idle_time(cpu); } else idle = usecs_to_cputime(idle_time); return idle; } -static cputime64_t get_iowait_time(int cpu) +static u64 get_iowait_time(int cpu) { - u64 iowait_time = get_cpu_iowait_time_us(cpu, NULL); - cputime64_t iowait; + u64 iowait, iowait_time = get_cpu_iowait_time_us(cpu, NULL); if (iowait_time == -1ULL) /* !NO_HZ so we can rely on cpustat.iowait */ - iowait = kstat_cpu(cpu).cpustat.iowait; + iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT]; else iowait = usecs_to_cputime(iowait_time); @@ -55,33 +53,30 @@ static int show_stat(struct seq_file *p, void *v) { int i, j; unsigned long jif; - cputime64_t user, nice, system, idle, iowait, irq, softirq, steal; - cputime64_t guest, guest_nice; + u64 user, nice, system, idle, iowait, irq, softirq, steal; + u64 guest, guest_nice; u64 sum = 0; u64 sum_softirq = 0; unsigned int per_softirq_sums[NR_SOFTIRQS] = {0}; struct timespec boottime; user = nice = system = idle = iowait = - irq = softirq = steal = cputime64_zero; - guest = guest_nice = cputime64_zero; + irq = softirq = steal = 0; + guest = guest_nice = 0; getboottime(&boottime); jif = boottime.tv_sec; for_each_possible_cpu(i) { - user = cputime64_add(user, kstat_cpu(i).cpustat.user); - nice = cputime64_add(nice, kstat_cpu(i).cpustat.nice); - system = cputime64_add(system, kstat_cpu(i).cpustat.system); - idle = cputime64_add(idle, get_idle_time(i)); - iowait = cputime64_add(iowait, get_iowait_time(i)); - irq = cputime64_add(irq, kstat_cpu(i).cpustat.irq); - softirq = cputime64_add(softirq, kstat_cpu(i).cpustat.softirq); - steal = cputime64_add(steal, kstat_cpu(i).cpustat.steal); - guest = cputime64_add(guest, kstat_cpu(i).cpustat.guest); - guest_nice = cputime64_add(guest_nice, - kstat_cpu(i).cpustat.guest_nice); - sum += kstat_cpu_irqs_sum(i); - sum += arch_irq_stat_cpu(i); + user += kcpustat_cpu(i).cpustat[CPUTIME_USER]; + nice += kcpustat_cpu(i).cpustat[CPUTIME_NICE]; + system += kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM]; + idle += get_idle_time(i); + iowait += get_iowait_time(i); + irq += kcpustat_cpu(i).cpustat[CPUTIME_IRQ]; + softirq += kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ]; + steal += kcpustat_cpu(i).cpustat[CPUTIME_STEAL]; + guest += kcpustat_cpu(i).cpustat[CPUTIME_GUEST]; + guest_nice += kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE]; for (j = 0; j < NR_SOFTIRQS; j++) { unsigned int softirq_stat = kstat_softirqs_cpu(j, i); @@ -106,16 +101,16 @@ static int show_stat(struct seq_file *p, void *v) (unsigned long long)cputime64_to_clock_t(guest_nice)); for_each_online_cpu(i) { /* Copy values here to work around gcc-2.95.3, gcc-2.96 */ - user = kstat_cpu(i).cpustat.user; - nice = kstat_cpu(i).cpustat.nice; - system = kstat_cpu(i).cpustat.system; + user = kcpustat_cpu(i).cpustat[CPUTIME_USER]; + nice = kcpustat_cpu(i).cpustat[CPUTIME_NICE]; + system = kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM]; idle = get_idle_time(i); iowait = get_iowait_time(i); - irq = kstat_cpu(i).cpustat.irq; - softirq = kstat_cpu(i).cpustat.softirq; - steal = kstat_cpu(i).cpustat.steal; - guest = kstat_cpu(i).cpustat.guest; - guest_nice = kstat_cpu(i).cpustat.guest_nice; + irq = kcpustat_cpu(i).cpustat[CPUTIME_IRQ]; + softirq = kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ]; + steal = kcpustat_cpu(i).cpustat[CPUTIME_STEAL]; + guest = kcpustat_cpu(i).cpustat[CPUTIME_GUEST]; + guest_nice = kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE]; seq_printf(p, "cpu%d %llu %llu %llu %llu %llu %llu %llu %llu %llu " "%llu\n", -- cgit v1.2.3 From 2a95ea6c0d129b4568fb64e1deda16ceb20e6636 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Thu, 8 Dec 2011 14:34:32 -0800 Subject: procfs: do not overflow get_{idle,iowait}_time for nohz Since commit a25cac5198d4 ("proc: Consider NO_HZ when printing idle and iowait times") we are reporting idle/io_wait time also while a CPU is tickless. We rely on get_{idle,iowait}_time functions to retrieve proper data. These functions, however, use usecs_to_cputime to translate micro seconds time to cputime64_t. This is just an alias to usecs_to_jiffies which reduces the data type from u64 to unsigned int and also checks whether the given parameter overflows jiffies_to_usecs(MAX_JIFFY_OFFSET) and returns MAX_JIFFY_OFFSET in that case. When we overflow depends on CONFIG_HZ but especially for CONFIG_HZ_300 it is quite low (1431649781) so we are getting MAX_JIFFY_OFFSET for >3000s! until we overflow unsigned int. Just for reference CONFIG_HZ_100 has an overflow window around 20s, CONFIG_HZ_250 ~8s and CONFIG_HZ_1000 ~2s. This results in a bug when people saw [h]top going mad reporting 100% CPU usage even though there was basically no CPU load. The reason was simply that /proc/stat stopped reporting idle/io_wait changes (and reported MAX_JIFFY_OFFSET) and so the only change happening was for user system time. Let's use nsecs_to_jiffies64 instead which doesn't reduce the precision to 32b type and it is much more appropriate for cumulative time values (unlike usecs_to_jiffies which intended for timeout calculations). Signed-off-by: Michal Hocko Tested-by: Artem S. Tashkinov Cc: Dave Jones Cc: Arnd Bergmann Cc: Alexey Dobriyan Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/stat.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/proc/stat.c') diff --git a/fs/proc/stat.c b/fs/proc/stat.c index 42b274da92c3..2a30d67dd6b8 100644 --- a/fs/proc/stat.c +++ b/fs/proc/stat.c @@ -32,7 +32,7 @@ static cputime64_t get_idle_time(int cpu) idle = kstat_cpu(cpu).cpustat.idle; idle = cputime64_add(idle, arch_idle_time(cpu)); } else - idle = usecs_to_cputime(idle_time); + idle = nsecs_to_jiffies64(1000 * idle_time); return idle; } @@ -46,7 +46,7 @@ static cputime64_t get_iowait_time(int cpu) /* !NO_HZ so we can rely on cpustat.iowait */ iowait = kstat_cpu(cpu).cpustat.iowait; else - iowait = usecs_to_cputime(iowait_time); + iowait = nsecs_to_jiffies64(1000 * iowait_time); return iowait; } -- cgit v1.2.3 From 34845636a184f3be91a531098192592cbe6db587 Mon Sep 17 00:00:00 2001 From: Andreas Schwab Date: Wed, 28 Dec 2011 15:57:15 -0800 Subject: procfs: do not confuse jiffies with cputime64_t Commit 2a95ea6c0d129b4 ("procfs: do not overflow get_{idle,iowait}_time for nohz") did not take into account that one some architectures jiffies and cputime use different units. This causes get_idle_time() to return numbers in the wrong units, making the idle time fields in /proc/stat wrong. Instead of converting the usec value returned by get_cpu_{idle,iowait}_time_us to units of jiffies, use the new function usecs_to_cputime64 to convert it to the correct unit of cputime64_t. Signed-off-by: Andreas Schwab Acked-by: Michal Hocko Cc: Arnd Bergmann Cc: "Artem S. Tashkinov" Cc: Dave Jones Cc: Alexey Dobriyan Cc: Thomas Gleixner Cc: "Luck, Tony" Cc: Benjamin Herrenschmidt Cc: Martin Schwidefsky Cc: Heiko Carstens Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/stat.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/proc/stat.c') diff --git a/fs/proc/stat.c b/fs/proc/stat.c index 2a30d67dd6b8..0855e6f20391 100644 --- a/fs/proc/stat.c +++ b/fs/proc/stat.c @@ -32,7 +32,7 @@ static cputime64_t get_idle_time(int cpu) idle = kstat_cpu(cpu).cpustat.idle; idle = cputime64_add(idle, arch_idle_time(cpu)); } else - idle = nsecs_to_jiffies64(1000 * idle_time); + idle = usecs_to_cputime64(idle_time); return idle; } @@ -46,7 +46,7 @@ static cputime64_t get_iowait_time(int cpu) /* !NO_HZ so we can rely on cpustat.iowait */ iowait = kstat_cpu(cpu).cpustat.iowait; else - iowait = nsecs_to_jiffies64(1000 * iowait_time); + iowait = usecs_to_cputime64(iowait_time); return iowait; } -- cgit v1.2.3 From f7e6746ebae984ea67b0a1a1e23c7e6698240631 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sat, 14 Jan 2012 00:01:01 +0000 Subject: sched/accounting, proc: Fix /proc/stat interrupts sum Commit 3292beb340c7688 ("sched/accounting: Change cpustat fields to an array") deleted the code which provides us with the sum of all interrupts in the system, causing vmstat to report zero interrupts occuring in the system. Fix this by restoring the code. Signed-off-by: Russell King Tested-by: Russell King # [on ARM] Tested-by: Tony Luck Tested-by: Steven Rostedt Cc: Glauber Costa Cc: KAMEZAWA Hiroyuki Cc: Linus Torvalds Cc: Andrew Morton Cc: Paul Tuner Cc: Peter Zijlstra Signed-off-by: Ingo Molnar --- fs/proc/stat.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/proc/stat.c') diff --git a/fs/proc/stat.c b/fs/proc/stat.c index d76ca6ae2b1b..121f77cfef76 100644 --- a/fs/proc/stat.c +++ b/fs/proc/stat.c @@ -77,6 +77,8 @@ static int show_stat(struct seq_file *p, void *v) steal += kcpustat_cpu(i).cpustat[CPUTIME_STEAL]; guest += kcpustat_cpu(i).cpustat[CPUTIME_GUEST]; guest_nice += kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE]; + sum += kstat_cpu_irqs_sum(i); + sum += arch_irq_stat_cpu(i); for (j = 0; j < NR_SOFTIRQS; j++) { unsigned int softirq_stat = kstat_softirqs_cpu(j, i); -- cgit v1.2.3