From 34845636a184f3be91a531098192592cbe6db587 Mon Sep 17 00:00:00 2001 From: Andreas Schwab Date: Wed, 28 Dec 2011 15:57:15 -0800 Subject: [PATCH] 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 --- arch/ia64/include/asm/cputime.h | 1 + arch/powerpc/include/asm/cputime.h | 2 ++ arch/s390/include/asm/cputime.h | 2 ++ fs/proc/stat.c | 4 ++-- include/asm-generic/cputime.h | 1 + 5 files changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/ia64/include/asm/cputime.h b/arch/ia64/include/asm/cputime.h index 6073b187528a..5a274af31b2b 100644 --- a/arch/ia64/include/asm/cputime.h +++ b/arch/ia64/include/asm/cputime.h @@ -60,6 +60,7 @@ typedef u64 cputime64_t; */ #define cputime_to_usecs(__ct) ((__ct) / NSEC_PER_USEC) #define usecs_to_cputime(__usecs) ((__usecs) * NSEC_PER_USEC) +#define usecs_to_cputime64(__usecs) usecs_to_cputime(__usecs) /* * Convert cputime <-> seconds diff --git a/arch/powerpc/include/asm/cputime.h b/arch/powerpc/include/asm/cputime.h index 1cf20bdfbeca..98b7c4b49c9d 100644 --- a/arch/powerpc/include/asm/cputime.h +++ b/arch/powerpc/include/asm/cputime.h @@ -150,6 +150,8 @@ static inline cputime_t usecs_to_cputime(const unsigned long us) return ct; } +#define usecs_to_cputime64(us) usecs_to_cputime(us) + /* * Convert cputime <-> seconds */ diff --git a/arch/s390/include/asm/cputime.h b/arch/s390/include/asm/cputime.h index 081434878296..b9acaaa175d8 100644 --- a/arch/s390/include/asm/cputime.h +++ b/arch/s390/include/asm/cputime.h @@ -87,6 +87,8 @@ usecs_to_cputime(const unsigned int m) return (cputime_t) m * 4096; } +#define usecs_to_cputime64(m) usecs_to_cputime(m) + /* * Convert cputime to milliseconds and back. */ 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; } diff --git a/include/asm-generic/cputime.h b/include/asm-generic/cputime.h index 62ce6823c0f2..12a1764f612b 100644 --- a/include/asm-generic/cputime.h +++ b/include/asm-generic/cputime.h @@ -40,6 +40,7 @@ typedef u64 cputime64_t; */ #define cputime_to_usecs(__ct) jiffies_to_usecs(__ct) #define usecs_to_cputime(__msecs) usecs_to_jiffies(__msecs) +#define usecs_to_cputime64(__msecs) nsecs_to_jiffies64((__msecs) * 1000) /* * Convert cputime to seconds and back. -- 2.39.2