The current time_before/time_after macros will fail typechecks
when passed u64 values (as returned by get_jiffies_64()). On 64bit
systems, this will just result in a warning about mismatching types
without explicit casts, but since unsigned long and u64
(unsigned long long) are of same size, it will still work.
On 32bit systems, a long is 32bits, so the value from get_jiffies_64()
will be truncated by the cast and thus lose all the precision gained by
64bit jiffies.
Signed-off-by: Dmitriy Zavin <[email protected]>
---
include/linux/jiffies.h | 15 +++++++++++++++
1 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h
index 329ebcf..c8d5f20 100644
--- a/include/linux/jiffies.h
+++ b/include/linux/jiffies.h
@@ -115,6 +115,21 @@ #define time_after_eq(a,b) \
((long)(a) - (long)(b) >= 0))
#define time_before_eq(a,b) time_after_eq(b,a)
+/* Same as above, but does so with platform independent 64bit types.
+ * These must be used when utilizing jiffies_64 (i.e. return value of
+ * get_jiffies_64() */
+#define time_after64(a,b) \
+ (typecheck(__u64, a) && \
+ typecheck(__u64, b) && \
+ ((__s64)(b) - (__s64)(a) < 0))
+#define time_before64(a,b) time_after64(b,a)
+
+#define time_after_eq64(a,b) \
+ (typecheck(__u64, a) && \
+ typecheck(__u64, b) && \
+ ((__s64)(a) - (__s64)(b) >= 0))
+#define time_before_eq64(a,b) time_after_eq64(b,a)
+
/*
* Have the 32 bit jiffies value wrap 5 minutes after boot
* so jiffies wrap bugs show up earlier.
--
1.4.2
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
