fio: fix cycles_start build issue
There is an issue introduced with "commit 73df3e07 gettime: offset CPU cycle
counter by initial value". For architectures which define
ARCH_CPU_CLOCK_CYCLES_PER_USEC (currently only s390) this causes a build
error
gettime.c:174:11: error: ‘cycles_start’ undeclared (first use in this
function)
if (t < cycles_start && !cycles_wrap)
To make sure variables and code are only compiled in the same cases I
added a
clock definition called ARCH_CPU_CLOCK_WRAPS. We could merge
ARCH_CPU_CLOCK_WRAPS and the existing ARCH_CPU_CLOCK_CYCLES_PER_USEC
into one
if you prefer, so far nobody else uses it.
To avoid cluttering all architecture headers I enabled it by default in
arch-generic.h, so any arch not needing the wrap handling can undef
ARCH_CPU_CLOCK_WRAPS later in their headers.
Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/arch/arch-s390.h b/arch/arch-s390.h
index 169282b..cc7a1d1 100644
--- a/arch/arch-s390.h
+++ b/arch/arch-s390.h
@@ -40,6 +40,7 @@
#define ARCH_CPU_CLOCK_CYCLES_PER_USEC 1
#define ARCH_HAVE_CPU_CLOCK
+#undef ARCH_CPU_CLOCK_WRAPS
#define ARCH_HAVE_INIT
extern int tsc_reliable;
diff --git a/arch/arch.h b/arch/arch.h
index 0075f73..5671b9a 100644
--- a/arch/arch.h
+++ b/arch/arch.h
@@ -30,6 +30,8 @@
extern unsigned long arch_flags;
+#define ARCH_CPU_CLOCK_WRAPS
+
#if defined(__i386__)
#include "arch-x86.h"
#elif defined(__x86_64__)
diff --git a/gettime.c b/gettime.c
index 6863ce3..d1c8eb9 100644
--- a/gettime.c
+++ b/gettime.c
@@ -17,6 +17,8 @@
static unsigned long cycles_per_usec;
static unsigned long inv_cycles_per_usec;
static uint64_t max_cycles_for_mult;
+#endif
+#ifdef ARCH_CPU_CLOCK_WRAPS
static unsigned long long cycles_start, cycles_wrap;
#endif
int tsc_reliable = 0;
@@ -171,6 +173,7 @@
#endif
t = get_cpu_clock();
+#ifdef ARCH_CPU_CLOCK_WRAPS
if (t < cycles_start && !cycles_wrap)
cycles_wrap = 1;
else if (cycles_wrap && t >= cycles_start && !tv->warned) {
@@ -179,6 +182,7 @@
}
t -= cycles_start;
+#endif
tv->last_cycles = t;
tv->last_tv_valid = 1;
#ifdef ARCH_CPU_CLOCK_CYCLES_PER_USEC
@@ -311,8 +315,10 @@
inv_cycles_per_usec = 16777216UL / cycles_per_usec;
max_cycles_for_mult = ~0ULL / inv_cycles_per_usec;
dprint(FD_TIME, "inv_cycles_per_usec=%lu\n", inv_cycles_per_usec);
+#ifdef ARCH_CPU_CLOCK_WRAPS
cycles_start = get_cpu_clock();
dprint(FD_TIME, "cycles_start=%llu\n", cycles_start);
+#endif
return 0;
}
#else