Messages in this thread Patch in this message | | | From | Sergei Shtylyov <> | Subject | [PATCH] 2.6.18-rt7: fix more issues with 32-bit cycles_t in latency_trace.c (take 2) | Date | Mon, 13 Nov 2006 21:33:40 +0300 |
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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@ru.mvista.com>
--- 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 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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