[PATCH] 2.6.18-rt7: fix more issues with 32-bit cycles_t in latency_trace.c (take 2)

From: Sergei Shtylyov
Date: Mon Nov 13 2006 - 13:32:26 EST


In addition to the clock jump-back check being falsely triggered by clock wrap
with 32-bit cycles_t, as noticed by Kevin Hilman, there's another issue: using
%Lx format to print 32-bit values warrants erroneous values on 32-bit machines
like ARM and PPC32...

Signed-off-by: Sergei Shtylyov <sshtylyov@xxxxxxxxxxxxx>

---
PPC32 actually has 64-bit timebase counter, so could provide for 64-bit
cycles_t -- maybe it's worth to rewrite get_cycles() to read both lower and
upper registers?

kernel/latency_trace.c | 10 +++++-----
1 files changed, 5 insertions(+), 5 deletions(-)

Index: linux-2.6/kernel/latency_trace.c
===================================================================
--- linux-2.6.orig/kernel/latency_trace.c
+++ linux-2.6/kernel/latency_trace.c
@@ -1623,8 +1623,8 @@ check_critical_timing(int cpu, struct cp
#ifndef CONFIG_CRITICAL_LATENCY_HIST
if (!preempt_thresh && preempt_max_latency > delta) {
printk("bug: updating %016Lx > %016Lx?\n",
- preempt_max_latency, delta);
- printk(" [%016Lx %016Lx %016Lx]\n", T0, T1, T2);
+ (u64)preempt_max_latency, (u64)delta);
+ printk(" [%016Lx %016Lx %016Lx]\n", (u64)T0, (u64)T1, (u64)T2);
}
#endif

@@ -2006,7 +2006,7 @@ check_wakeup_timing(struct cpu_trace *tr
____trace(smp_processor_id(), TRACE_FN, tr, CALLER_ADDR0, parent_eip, 0, 0, 0, *flags);
T2 = get_cycles();
if (T2 < T1)
- printk("bug2: %016Lx < %016Lx!\n", T2, T1);
+ printk("bug2: %016Lx < %016Lx!\n", (u64)T2, (u64)T1);
delta = T2-T0;

latency = cycles_to_usecs(delta);
@@ -2023,8 +2023,8 @@ check_wakeup_timing(struct cpu_trace *tr
#ifndef CONFIG_WAKEUP_LATENCY_HIST
if (!preempt_thresh && preempt_max_latency > delta) {
printk("bug2: updating %016Lx > %016Lx?\n",
- preempt_max_latency, delta);
- printk(" [%016Lx %016Lx %016Lx]\n", T0, T1, T2);
+ (u64)preempt_max_latency, (u64)delta);
+ printk(" [%016Lx %016Lx %016Lx]\n", (u64)T0, (u64)T1, (u64)T2);
}
#endif


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