* [Xenomai-core] enjoying the trace
@ 2006-01-04 21:50 Jan Kiszka
2006-01-04 22:45 ` Jan Kiszka
0 siblings, 1 reply; 2+ messages in thread
From: Jan Kiszka @ 2006-01-04 21:50 UTC (permalink / raw)
To: xenomai-core
[-- Attachment #1.1: Type: text/plain, Size: 1954 bytes --]
Hi all,
after a long day of experimenting with a new tracer revision (will get
posted later), I'm looking now for some external wisdom.
I changed the instrumentation for high-domain stall times such that I
now attach to local_irq_disable_hw & friends instead. In case the
hard-IRQ status doesn't change, only a ipipe_trace_special is issued, a
trace_begin/end otherwise. Additionally, I grab the entering and exiting
of __ipipe_handle_irq and suppress two IRQ on/off points in
arch/i386/kernel/ipipe-root.c. See attached patch (will likely become
part of the tracer).
Ok, this works significantly better than the previous approach. I just
tormented an Athlon 800 MHz box with Xenomai 2.1 revision 357 (old ipipe
IRQ layer) about 50 minutes with
latency -p1000 -t1
dd if=/dev/hda of=/dev/null
ping -f -s 1400 [from external]
cachebench [part of llcbench]
The result was a maximum latency of 38 us (in-kernel periodic task) and
some traces which correlate quite well. I attached two of them, showing
the similarity between the final and last but one outputs of
/proc/ipipe/trace/max. Note that the instrumentation and the trace
recording add some overhead, how much is just going to be measured.
So far so good. But I still have at least one virtual IRQ leakage in my
instrumenation, see the third trace. This is where the "external wisdom"
would be welcome. I know, I'm not tracing all IRQ offs and ons to make
life easier. This one is like an IRQ-reenable-on-iret when return to
userspace (the following IRQ hits a userspace address). Any ideas how to
catch this without rewriting entry.S - where modifications are real
*slowly* maturing?
Thanks,
Jan
PS: The removal of rthal_irq_trampoline() should not cause noticable
positive effects on such mid-range platforms, I'm afraid. But this will
get checked later. And there is a "nice" Pentium I 133 MHz sitting next
to me. I guess he will like this more. :)
PPS: "later" may not mean "soon".
[-- Attachment #1.2: xeno-2.1-athlon800.trace --]
[-- Type: text/plain, Size: 5539 bytes --]
I-pipe worst-case tracing service on 2.6.14.3/ipipe-1.1-00
------------------------------------------------------------
Begin: 1068123402870 cycles, Trace Points: 44 (-10/+5), Length: 36 us
Type User Val. Time Delay Function (Parent)
fn -3 0.381 losyscall_event+0xc (__ipipe_dispatch_event+0x88)
begin 0x80000001 -3 0.252 __ipipe_dispatch_event+0xb0 (__ipipe_syscall_root+0x31)
end 0x80000001 -3 0.399 __ipipe_dispatch_event+0x160 (__ipipe_syscall_root+0x31)
fn -2 0.136 sys_write+0xd (syscall_call+0x7)
fn -2 0.295 fget_light+0xb (sys_write+0x1d)
fn -2 0.402 vfs_write+0xc (sys_write+0x41)
fn -1 0.186 rw_verify_area+0xb (vfs_write+0x67)
fn -1 0.160 write_null+0x8 (vfs_write+0x8a)
fn -1 0.400 dnotify_parent+0xa (vfs_write+0xb5)
fn -1 1.053 inotify_dentry_parent_queue_event+0xa (vfs_write+0xd5)
>|begin 0x80000002 0 0.451 common_interrupt+0x21 (__ipipe_trace+0x160)
:|fn 0 0.904 __ipipe_handle_irq+0xe (common_interrupt+0x29)
:|fn 1 0.438 __ipipe_ack_common_irq+0xb (__ipipe_handle_irq+0xf5)
:|fn 1 0.392 mask_and_ack_8259A+0xc (__ipipe_ack_common_irq+0xa4)
:|(0x11) 0x80000001 2! 13.393 mask_and_ack_8259A+0x9f (__ipipe_ack_common_irq+0xa4)
:|(0x22) 0x80000001 15 0.267 mask_and_ack_8259A+0x124 (__ipipe_ack_common_irq+0xa4)
:|fn 15+ 1.448 __ipipe_sync_stage+0xe (__ipipe_handle_irq+0x225)
:|begin 0x80000002 17 0.163 common_interrupt+0x21 (__ipipe_sync_stage+0xdd)
:|fn 17 0.423 __ipipe_handle_irq+0xe (common_interrupt+0x29)
:|fn 17 0.158 __ipipe_ack_common_irq+0xb (__ipipe_handle_irq+0xf5)
:|fn 18 0.178 mask_and_ack_8259A+0xc (__ipipe_ack_common_irq+0xa4)
:|(0x11) 0x80000001 18+ 1.712 mask_and_ack_8259A+0x9f (__ipipe_ack_common_irq+0xa4)
:|(0x22) 0x80000001 19 0.350 mask_and_ack_8259A+0x124 (__ipipe_ack_common_irq+0xa4)
:|fn 20 0.198 ipipe_suspend_domain+0xc (__ipipe_handle_irq+0x1cc)
:|(0x11) 0x80000001 20 0.349 ipipe_suspend_domain+0xac (__ipipe_handle_irq+0x1cc)
:|fn 20 0.285 __ipipe_sync_stage+0xe (ipipe_suspend_domain+0x68)
:|fn 21 0.311 rthal_irq_trampoline+0x8 (__ipipe_sync_stage+0xc1)
:|fn 21 0.155 xnintr_clock_handler+0x8 (rthal_irq_trampoline+0x2c)
:|fn 21 0.195 xnintr_irq_handler+0xb (xnintr_clock_handler+0x18)
:|fn 21 0.454 xnpod_announce_tick+0xb (xnintr_irq_handler+0x28)
:|(0x11) 0x80000000 22 0.220 xnpod_announce_tick+0x214 (xnintr_irq_handler+0x28)
:|fn 22 0.298 xntimer_do_tick_aperiodic+0xe (xnpod_announce_tick+0xb8)
:|fn 22 0.425 xnthread_timeout_handler+0x8 (xntimer_do_tick_aperiodic+0x273)
:|fn 23 0.148 xnpod_resume_thread+0xc (xnthread_timeout_handler+0x22)
:|(0x11) 0x80000000 23 0.362 xnpod_resume_thread+0x350 (xnthread_timeout_handler+0x22)
:|(0x11) 0x80000000 23 0.319 xnpod_resume_thread+0x21b (xnthread_timeout_handler+0x22)
:|(0x11) 0x80000001 24+ 2.933 xntimer_do_tick_aperiodic+0x20c (xnpod_announce_tick+0xb8)
:|(0x22) 0x80000001 26 0.320 xntimer_do_tick_aperiodic+0x233 (xnpod_announce_tick+0xb8)
:|(0x11) 0x80000000 27 0.202 xnpod_announce_tick+0x183 (xnintr_irq_handler+0x28)
:|fn 27 0.159 xnpod_schedule+0xe (xnintr_irq_handler+0xa5)
:|(0x11) 0x80000000 27+ 1.029 xnpod_schedule+0x68a (xnintr_irq_handler+0xa5)
:|(0x11) 0x80000000 28 0.214 xnpod_schedule+0x985 (xnpod_suspend_thread+0x2b7)
:|(0x11) 0x80000000 28 0.325 xnpod_suspend_thread+0x1ba (rtdm_task_sleep_until+0x99 [xeno_rtdm])
:|(0x11) 0x80000000 29 0.194 rtdm_task_sleep_until+0xe4 [xeno_rtdm] (timer_task_proc+0x12c [xeno_timerbench])
:|fn 29 0.190 ipipe_unstall_pipeline_from+0xd (timer_task_proc+0x145 [xeno_timerbench])
:|(0x11) 0x80000001 29+ 1.144 ipipe_unstall_pipeline_from+0x90 (timer_task_proc+0x145 [xeno_timerbench])
:|begin 0x80000002 30 0.162 common_interrupt+0x21 (ipipe_unstall_pipeline_from+0xff)
:|fn 30 0.237 __ipipe_handle_irq+0xe (common_interrupt+0x29)
:|fn 31 0.397 __ipipe_ack_common_irq+0xb (__ipipe_handle_irq+0xf5)
:|(0x11) 0x80000000 31 0.176 __ipipe_ack_common_irq+0xd3 (__ipipe_handle_irq+0xf5)
:|fn 31 0.315 mask_and_ack_8259A+0xc (__ipipe_ack_common_irq+0x40)
:|(0x11) 0x80000001 32+ 4.283 mask_and_ack_8259A+0x9f (__ipipe_ack_common_irq+0x40)
:|(0x22) 0x80000001 36 0.300 mask_and_ack_8259A+0x124 (__ipipe_ack_common_irq+0x40)
<|end 0x80000002 36 0.470 common_interrupt+0x34 (ipipe_unstall_pipeline_from+0xff)
end 0x80000000 37 0.236 ipipe_unstall_pipeline_from+0x104 (timer_task_proc+0x145 [xeno_timerbench])
fn 37 0.186 xnpod_get_time+0x8 (timer_task_proc+0x8c [xeno_timerbench])
fn 37 0.575 xntimer_get_jiffies_aperiodic+0xe (xnpod_get_time+0x10)
fn 38 0.202 eval_inner_loop+0xb [xeno_timerbench] (timer_task_proc+0xb2 [xeno_timerbench])
begin 0x80000000 38 0.000 timer_task_proc+0x166 [xeno_timerbench] (xnarch_thread_redirect+0x97)
[-- Attachment #1.3: xeno-2.1-athlon800.trace2 --]
[-- Type: text/plain, Size: 5570 bytes --]
I-pipe worst-case tracing service on 2.6.14.3/ipipe-1.1-00
------------------------------------------------------------
Begin: 1625655337641 cycles, Trace Points: 44 (-10/+5), Length: 38 us
Type User Val. Time Delay Function (Parent)
fn -5 0.126 __ipipe_unstall_root+0x8 (find_get_page+0x3b)
begin 0x80000000 -5 0.368 __ipipe_unstall_root+0x19 (find_get_page+0x3b)
end 0x80000000 -5 0.225 __ipipe_unstall_root+0x43 (find_get_page+0x3b)
fn -5 0.387 file_read_actor+0xd (do_generic_mapping_read+0x3c8)
fn -4 2.175 __copy_to_user_ll+0xa (file_read_actor+0x77)
fn -2 0.311 update_atime+0xc (do_generic_mapping_read+0x41b)
fn -2 0.394 current_fs_time+0xe (update_atime+0x51)
fn -1 0.215 timespec_trunc+0xb (current_fs_time+0x65)
fn -1 0.206 dnotify_parent+0xa (vfs_read+0xb5)
fn -1 1.337 inotify_dentry_parent_queue_event+0xa (vfs_read+0xd5)
>|begin 0x80000002 0 0.226 common_interrupt+0x21 (mcount+0x29)
:|fn 0 0.907 __ipipe_handle_irq+0xe (common_interrupt+0x29)
:|fn 1 0.417 __ipipe_ack_common_irq+0xb (__ipipe_handle_irq+0xf5)
:|fn 1 0.136 mask_and_ack_8259A+0xc (__ipipe_ack_common_irq+0xa4)
:|(0x11) 0x80000001 1! 12.181 mask_and_ack_8259A+0x9f (__ipipe_ack_common_irq+0xa4)
:|(0x22) 0x80000001 13 0.283 mask_and_ack_8259A+0x124 (__ipipe_ack_common_irq+0xa4)
:|fn 14+ 1.431 __ipipe_sync_stage+0xe (__ipipe_handle_irq+0x225)
:|begin 0x80000002 15 0.371 common_interrupt+0x21 (__ipipe_sync_stage+0xdd)
:|fn 15 0.219 __ipipe_handle_irq+0xe (common_interrupt+0x29)
:|fn 16 0.313 __ipipe_ack_common_irq+0xb (__ipipe_handle_irq+0xf5)
:|fn 16 0.176 mask_and_ack_8259A+0xc (__ipipe_ack_common_irq+0xa4)
:|(0x11) 0x80000001 16+ 3.290 mask_and_ack_8259A+0x9f (__ipipe_ack_common_irq+0xa4)
:|(0x22) 0x80000001 19 0.577 mask_and_ack_8259A+0x124 (__ipipe_ack_common_irq+0xa4)
:|fn 20 0.201 ipipe_suspend_domain+0xc (__ipipe_handle_irq+0x1cc)
:|(0x11) 0x80000001 20 0.200 ipipe_suspend_domain+0xac (__ipipe_handle_irq+0x1cc)
:|fn 20 0.529 __ipipe_sync_stage+0xe (ipipe_suspend_domain+0x68)
:|fn 21 0.217 rthal_irq_trampoline+0x8 (__ipipe_sync_stage+0xc1)
:|fn 21 0.358 xnintr_clock_handler+0x8 (rthal_irq_trampoline+0x2c)
:|fn 22 0.199 xnintr_irq_handler+0xb (xnintr_clock_handler+0x18)
:|fn 22 0.220 xnpod_announce_tick+0xb (xnintr_irq_handler+0x28)
:|(0x11) 0x80000000 22 0.585 xnpod_announce_tick+0x214 (xnintr_irq_handler+0x28)
:|fn 23 0.311 xntimer_do_tick_aperiodic+0xe (xnpod_announce_tick+0xb8)
:|fn 23 0.205 xnthread_timeout_handler+0x8 (xntimer_do_tick_aperiodic+0x273)
:|fn 23 0.475 xnpod_resume_thread+0xc (xnthread_timeout_handler+0x22)
:|(0x11) 0x80000000 24 0.361 xnpod_resume_thread+0x350 (xnthread_timeout_handler+0x22)
:|(0x11) 0x80000000 24 0.373 xnpod_resume_thread+0x21b (xnthread_timeout_handler+0x22)
:|(0x11) 0x80000001 24+ 2.892 xntimer_do_tick_aperiodic+0x20c (xnpod_announce_tick+0xb8)
:|(0x22) 0x80000001 27 0.209 xntimer_do_tick_aperiodic+0x233 (xnpod_announce_tick+0xb8)
:|(0x11) 0x80000000 27 0.474 xnpod_announce_tick+0x183 (xnintr_irq_handler+0x28)
:|fn 28 0.363 xnpod_schedule+0xe (xnintr_irq_handler+0xa5)
:|(0x11) 0x80000000 28 0.936 xnpod_schedule+0x68a (xnintr_irq_handler+0xa5)
:|(0x11) 0x80000000 29 0.550 xnpod_schedule+0x985 (xnpod_suspend_thread+0x2b7)
:|(0x11) 0x80000000 30 0.288 xnpod_suspend_thread+0x1ba (rtdm_task_sleep_until+0x99 [xeno_rtdm])
:|(0x11) 0x80000000 30 0.334 rtdm_task_sleep_until+0xe4 [xeno_rtdm] (timer_task_proc+0x12c [xeno_timerbench])
:|fn 30 0.186 ipipe_unstall_pipeline_from+0xd (timer_task_proc+0x145 [xeno_timerbench])
:|(0x11) 0x80000001 31 0.912 ipipe_unstall_pipeline_from+0x90 (timer_task_proc+0x145 [xeno_timerbench])
:|begin 0x80000002 31 0.303 common_interrupt+0x21 (ipipe_unstall_pipeline_from+0xff)
:|fn 32 0.226 __ipipe_handle_irq+0xe (common_interrupt+0x29)
:|fn 32 0.191 __ipipe_ack_common_irq+0xb (__ipipe_handle_irq+0xf5)
:|(0x11) 0x80000000 32 0.417 __ipipe_ack_common_irq+0xd3 (__ipipe_handle_irq+0xf5)
:|fn 33 0.136 mask_and_ack_8259A+0xc (__ipipe_ack_common_irq+0x40)
:|(0x11) 0x80000001 33+ 4.519 mask_and_ack_8259A+0x9f (__ipipe_ack_common_irq+0x40)
:|(0x22) 0x80000001 37 0.290 mask_and_ack_8259A+0x124 (__ipipe_ack_common_irq+0x40)
<|end 0x80000002 38 0.306 common_interrupt+0x34 (ipipe_unstall_pipeline_from+0xff)
end 0x80000000 38 0.397 ipipe_unstall_pipeline_from+0x104 (timer_task_proc+0x145 [xeno_timerbench])
fn 38 0.165 xnpod_get_time+0x8 (timer_task_proc+0x8c [xeno_timerbench])
fn 38 0.313 xntimer_get_jiffies_aperiodic+0xe (xnpod_get_time+0x10)
fn 39 0.638 eval_inner_loop+0xb [xeno_timerbench] (timer_task_proc+0xb2 [xeno_timerbench])
begin 0x80000000 39 0.000 timer_task_proc+0x166 [xeno_timerbench] (xnarch_thread_redirect+0x97)
[-- Attachment #1.4: leaking-irq.trace --]
[-- Type: text/plain, Size: 3626 bytes --]
Type User Val. Time Delay Function (Parent)
fn -9 0.149 activate_task+0xb (try_to_wake_up+0x100)
fn -9 0.836 sched_clock+0xd (activate_task+0x13)
fn -8 1.616 recalc_task_prio+0xe (activate_task+0x1f)
fn -6 0.250 effective_prio+0x8 (recalc_task_prio+0x17d)
fn -6 0.825 enqueue_task+0xa (activate_task+0x59)
fn -5 0.136 __ipipe_restore_root+0x8 (try_to_wake_up+0x4d)
fn -5 0.309 __ipipe_stall_root+0x8 (__ipipe_restore_root+0x11)
fn -5 0.527 preempt_schedule+0xb (try_to_wake_up+0x8b)
fn -4 0.175 xnpod_schedule+0xe (lostage_handler+0x115)
fn -4 0.720 ipipe_trigger_irq+0xe (xnpod_schedule+0x660)
begin 0x80000001 -3 0.430 ipipe_trigger_irq+0xac (xnpod_schedule+0x660)
|fn -3 0.566 __ipipe_handle_irq+0xe (ipipe_trigger_irq+0x55)
|fn -2 0.315 ipipe_suspend_domain+0xc (__ipipe_handle_irq+0x1cc)
|fn -2 0.455 __ipipe_sync_stage+0xe (ipipe_suspend_domain+0x59)
|fn -2 0.165 xnpod_schedule_handler+0x8 (__ipipe_sync_stage+0xca)
|fn -1 0.694 xnpod_schedule+0xe (xnpod_schedule_handler+0x17)
end 0x80000001 -1 0.332 ipipe_trigger_irq+0x7a (xnpod_schedule+0x660)
fn 0 0.228 __ipipe_stall_root+0x8 (resume_kernel+0x5)
fn 0 0.518 __ipipe_unstall_iret_root+0x8 (restore_raw+0x0)
fn 0 0.189 irq_exit+0x8 (__ipipe_sync_stage+0x177)
> begin 0x80000000 0! 874.819 __ipipe_sync_stage+0x120 (__ipipe_unstall_iret_root+0x42)
:|begin 0x80000002 874 0.157 common_interrupt+0x21 (<b7f2a1e3>)
:|fn 874 0.356 __ipipe_handle_irq+0xe (common_interrupt+0x29)
:|fn 875 0.888 __ipipe_ack_common_irq+0xb (__ipipe_handle_irq+0xf5)
:|fn 876+ 1.780 mask_and_ack_8259A+0xc (__ipipe_ack_common_irq+0xa4)
:|fn 878 0.152 ipipe_suspend_domain+0xc (__ipipe_handle_irq+0x1cc)
:|fn 878 0.502 __ipipe_sync_stage+0xe (ipipe_suspend_domain+0x59)
:|fn 878 0.181 rthal_irq_trampoline+0x8 (__ipipe_sync_stage+0xca)
:|fn 878 0.315 xnintr_clock_handler+0x8 (rthal_irq_trampoline+0x2c)
:|fn 879 0.179 xnintr_irq_handler+0xb (xnintr_clock_handler+0x18)
:|fn 879 0.290 xnpod_announce_tick+0xb (xnintr_irq_handler+0x28)
:|fn 879 0.597 xntimer_do_tick_aperiodic+0xe (xnpod_announce_tick+0xb8)
:|fn 880 0.139 xnthread_timeout_handler+0x8 (xntimer_do_tick_aperiodic+0x240)
:|fn 880+ 3.327 xnpod_resume_thread+0xc (xnthread_timeout_handler+0x22)
:|fn 883+ 1.346 xnpod_schedule+0xe (xnintr_irq_handler+0xa5)
:|fn 885 0.188 ipipe_unstall_pipeline_from+0xd (timer_task_proc+0x145 [xeno_timerbench])
< end 0x80000000 885 0.375 ipipe_unstall_pipeline_from+0xd3 (timer_task_proc+0x145 [xeno_timerbench])
fn 885 0.137 xnpod_get_time+0x8 (timer_task_proc+0x8c [xeno_timerbench])
fn 885 0.293 xntimer_get_jiffies_aperiodic+0xe (xnpod_get_time+0x10)
fn 886 0.516 eval_inner_loop+0xb [xeno_timerbench] (timer_task_proc+0xb2 [xeno_timerbench])
begin 0x80000000 886 0.000 timer_task_proc+0x166 [xeno_timerbench] (xnarch_thread_redirect+0x97)
[-- Attachment #1.5: ipipe_trace.instr2 --]
[-- Type: text/plain, Size: 4016 bytes --]
--- linux-2.6.14.3//arch/i386/kernel/ipipe-root.c.orig 2006-01-02 20:42:58.000000000 +0100
+++ linux-2.6.14.3//arch/i386/kernel/ipipe-root.c 2006-01-04 01:26:16.000000000 +0100
@@ -283,7 +283,7 @@ asmlinkage int __ipipe_kpreempt_root(str
}
__ipipe_stall_root();
- local_irq_enable_hw();
+ local_irq_enable_hw_notrace();
return 1; /* Ok, may reschedule now. */
}
@@ -294,7 +294,7 @@ asmlinkage void __ipipe_unstall_iret_roo
/* Emulate IRET's handling of the interrupt flag. */
- local_irq_disable_hw();
+ local_irq_disable_hw_notrace();
ipipe_load_cpuid();
--- linux-2.6.14.3//include/asm-i386/system.h.orig 2006-01-03 19:05:32.000000000 +0100
+++ linux-2.6.14.3//include/asm-i386/system.h 2006-01-04 22:15:53.000000000 +0100
@@ -481,18 +481,82 @@ void fastcall __ipipe_restore_root(unsig
#define irqs_disabled() __ipipe_test_root()
+#define halt() __asm__ __volatile__("hlt": : :"memory")
+
+#ifdef CONFIG_IPIPE_TRACE_IRQSOFF
+
+#include <linux/ipipe_trace.h>
+
#define safe_halt() do { \
- __ipipe_unstall_root(); \
- __asm__ __volatile__("sti; hlt": : :"memory"); \
+ __ipipe_unstall_root(); \
+ __asm__ __volatile__("sti": : :"memory"); \
+ ipipe_trace_end(0x8000000E); \
+ __asm__ __volatile__("hlt": : :"memory"); \
} while(0)
-#define halt() __asm__ __volatile__("hlt": : :"memory")
+#define ipipe_hw_save_flags_and_sti(x) do { \
+ __asm__ __volatile__("pushfl ; popl %0 ; sti":"=g" (x): /* no input */ :"memory"); \
+ ipipe_trace_end(0x8000000F); \
+} while (0)
+#define local_irq_disable_hw() do { \
+ if (!irqs_disabled_hw()) { \
+ ipipe_trace_begin(0x80000000); \
+ __asm__ __volatile__("cli": : :"memory"); \
+ } else \
+ ipipe_trace_special(0x11, 0x80000000); \
+} while (0)
+#define local_irq_enable_hw() do { \
+ if (irqs_disabled_hw()) { \
+ __asm__ __volatile__("sti": : :"memory"); \
+ ipipe_trace_end(0x80000000); \
+ } else \
+ ipipe_trace_special(0x22, 0x80000000); \
+} while (0)
+#define local_irq_save_hw(x) do { \
+ local_save_flags_hw(x); \
+ if (local_test_iflag_hw(x)) { \
+ ipipe_trace_begin(0x80000001); \
+ __asm__ __volatile__("cli": : :"memory"); \
+ } else \
+ ipipe_trace_special(0x11, 0x80000001); \
+} while (0)
+#define local_irq_restore_hw(x) do { \
+ __asm__ __volatile__("pushl %0 ; popfl": /* no output */ :"g" (x):"memory", "cc"); \
+ if (local_test_iflag_hw(x)) \
+ ipipe_trace_end(0x80000001); \
+ else \
+ ipipe_trace_special(0x22, 0x80000001); \
+} while (0)
+
+#define local_irq_disable_hw_notrace() \
+ __asm__ __volatile__("cli": : :"memory")
+#define local_irq_enable_hw_notrace() \
+ __asm__ __volatile__("sti": : :"memory")
+#define local_irq_save_hw_notrace(x) \
+ __asm__ __volatile__("pushfl ; popl %0 ; cli":"=g" (x): /* no input */ :"memory")
+#define local_irq_restore_hw_notrace(x) \
+ __asm__ __volatile__("pushl %0 ; popfl": /* no output */ :"g" (x):"memory", "cc")
+
+#else /* !CONFIG_IPIPE_TRACE_IRQSOFF */
+
+#define safe_halt() do { \
+ __ipipe_unstall_root(); \
+ __asm__ __volatile__("sti; hlt": : :"memory"); \
+} while(0)
#define ipipe_hw_save_flags_and_sti(x) __asm__ __volatile__("pushfl ; popl %0 ; sti":"=g" (x): /* no input */ :"memory")
#define local_irq_disable_hw() __asm__ __volatile__("cli": : :"memory")
#define local_irq_enable_hw() __asm__ __volatile__("sti": : :"memory")
#define local_irq_save_hw(x) __asm__ __volatile__("pushfl ; popl %0 ; cli":"=g" (x): /* no input */ :"memory")
#define local_irq_restore_hw(x) __asm__ __volatile__("pushl %0 ; popfl": /* no output */ :"g" (x):"memory", "cc")
+
+#define local_irq_disable_hw_notrace local_irq_disable_hw
+#define local_irq_enable_hw_notrace local_irq_enable_hw
+#define local_irq_save_hw_notrace local_irq_save_hw
+#define local_irq_restore_hw_notrace local_irq_restore_hw
+
+#endif /* CONFIG_IPIPE_TRACE_IRQSOFF */
+
#define local_save_flags_hw(x) __asm__ __volatile__("pushfl ; popl %0":"=g" (x): /* no input */)
#define local_test_iflag_hw(x) ((x) & (1<<9))
#define irqs_disabled_hw() \
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 256 bytes --]
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [Xenomai-core] enjoying the trace
2006-01-04 21:50 [Xenomai-core] enjoying the trace Jan Kiszka
@ 2006-01-04 22:45 ` Jan Kiszka
0 siblings, 0 replies; 2+ messages in thread
From: Jan Kiszka @ 2006-01-04 22:45 UTC (permalink / raw)
To: xenomai-core
[-- Attachment #1: Type: text/plain, Size: 1457 bytes --]
Jan Kiszka wrote:
> Hi all,
>
> after a long day of experimenting with a new tracer revision (will get
> posted later), I'm looking now for some external wisdom.
>
> I changed the instrumentation for high-domain stall times such that I
> now attach to local_irq_disable_hw & friends instead. In case the
> hard-IRQ status doesn't change, only a ipipe_trace_special is issued, a
> trace_begin/end otherwise. Additionally, I grab the entering and exiting
> of __ipipe_handle_irq and suppress two IRQ on/off points in
> arch/i386/kernel/ipipe-root.c. See attached patch (will likely become
> part of the tracer).
I failed to include the changes of entry.S, see the full patch posted in
the related thread.
>
> Ok, this works significantly better than the previous approach. I just
> tormented an Athlon 800 MHz box with Xenomai 2.1 revision 357 (old ipipe
> IRQ layer) about 50 minutes with
>
> latency -p1000 -t1
> dd if=/dev/hda of=/dev/null
> ping -f -s 1400 [from external]
> cachebench [part of llcbench]
>
> The result was a maximum latency of 38 us (in-kernel periodic task) and
> some traces which correlate quite well. I attached two of them, showing
> the similarity between the final and last but one outputs of
> /proc/ipipe/trace/max. Note that the instrumentation and the trace
> recording add some overhead, how much is just going to be measured.
>
Result: 33 us without the tracer but otherwise identical boundary
conditions.
Jan
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 256 bytes --]
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2006-01-04 22:45 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2006-01-04 21:50 [Xenomai-core] enjoying the trace Jan Kiszka
2006-01-04 22:45 ` Jan Kiszka
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.