lkml.org 
[lkml]   [2008]   [Nov]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] tracing/function-graph-tracer: adjustments of the trace informations

another detail: it would be nice to annotate IRQ entries some more.

right now if a syscall is interrupted by a hardware interrupt, it looks
like this:

0) | skb_dequeue() {
0) 0.365 us | _spin_lock_irqsave();
0) 0.422 us | _spin_unlock_irqrestore();
0) 1.912 us | }
0) | memcpy_toiovec() {
0) | copy_to_user() {
0) | smp_apic_timer_interrupt() {
0) 0.450 us | native_apic_mem_write();
0) | irq_enter() {
0) 0.410 us | idle_cpu();
0) 1.167 us | }
0) | hrtimer_interrupt() {

the natural nesting is nice, but easy to miss. It would be nice to have
something like:

0) | skb_dequeue() {
0) 0.365 us | _spin_lock_irqsave();
0) 0.422 us | _spin_unlock_irqrestore();
0) 1.912 us | }
0) | memcpy_toiovec() {
0) | copy_to_user() {
0) =====> smp_apic_timer_interrupt() {
0) 0.450 us | native_apic_mem_write();
0) | irq_enter() {
0) 0.410 us | idle_cpu();
0) 1.167 us | }
0) | hrtimer_interrupt() {

and perhaps something like this at the end of the irq frame:

0) 0.408 us | _local_bh_enable();
0) + 13.139 us | }
0) + 13.887 us | }
0) 0.406 us | idle_cpu();
0) + 15.373 us | }
0) + 74.564 us | }
0) | _cond_resched() {
0) | need_resched() {
0) 0.423 us | constant_test_bit();
0) 1.164 us | }
0) 1.915 us <=== } /* IRQ 1 end */
0) + 78.396 us | }
0) + 79.123 us | }
0) 0.387 us | skb_pull();
0) | kfree_skb() {

?

Ingo


\
 
 \ /
  Last update: 2008-11-28 20:25    [W:0.227 / U:0.232 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site