diff options
| author | Eric Dumazet <edumazet@google.com> | 2012-08-08 21:13:53 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-08-09 16:17:03 -0700 |
| commit | a399a8053164ec8bcb06fed52be9941a26ecde11 (patch) | |
| tree | c60402a77d08c82630d63e972d32b038919b827f /include/linux/jiffies.h | |
| parent | 79cda75a107da0d49732b5cb642b456264dd7e0e (diff) | |
time: jiffies_delta_to_clock_t() helper to the rescue
Various /proc/net files sometimes report crazy timer values, expressed
in clock_t units.
This happens when an expired timer delta (expires - jiffies) is passed
to jiffies_to_clock_t().
This function has an overflow in :
return div_u64((u64)x * TICK_NSEC, NSEC_PER_SEC / USER_HZ);
commit cbbc719fccdb8cb (time: Change jiffies_to_clock_t() argument type
to unsigned long) only got around the problem.
As we cant output negative values in /proc/net/tcp without breaking
various tools, I suggest adding a jiffies_delta_to_clock_t() wrapper
that caps the negative delta to a 0 value.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Maciej Żenczykowski <maze@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: hank <pyu@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/jiffies.h')
| -rw-r--r-- | include/linux/jiffies.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h index 265e2c3cbd1c..aded9b1ac5ca 100644 --- a/include/linux/jiffies.h +++ b/include/linux/jiffies.h @@ -303,7 +303,13 @@ extern void jiffies_to_timespec(const unsigned long jiffies, extern unsigned long timeval_to_jiffies(const struct timeval *value); extern void jiffies_to_timeval(const unsigned long jiffies, struct timeval *value); + extern clock_t jiffies_to_clock_t(unsigned long x); +static inline clock_t jiffies_delta_to_clock_t(long delta) +{ + return jiffies_to_clock_t(max(0L, delta)); +} + extern unsigned long clock_t_to_jiffies(unsigned long x); extern u64 jiffies_64_to_clock_t(u64 x); extern u64 nsec_to_clock_t(u64 x); |