From: Dario Faggioli <dario.faggioli@citrix.com>
To: xen-devel@lists.xenproject.org
Cc: Stefano Stabellini <sstabellini@kernel.org>,
George Dunlap <George.Dunlap@eu.citrix.com>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Tim Deegan <tim@xen.org>, Jan Beulich <jbeulich@suse.com>
Subject: [PATCH 10/15] xen: trace softirqs
Date: Thu, 01 Jun 2017 19:34:46 +0200 [thread overview]
Message-ID: <149633848683.12814.7037656355338256775.stgit@Solace.fritz.box> (raw)
In-Reply-To: <149633614204.12814.14390287626133023934.stgit@Solace.fritz.box>
Making it possible generate events showing the
activity and the behavior of the softirq subsystem.
Gate this with its specific Kconfig option (under
CONFIG_TRACING), and keep it in disabled state by
default.
---
Cc: George Dunlap <George.Dunlap@eu.citrix.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Tim Deegan <tim@xen.org>
---
xen/Kconfig.debug | 8 ++++++
xen/common/softirq.c | 58 ++++++++++++++++++++++++++++++++++++++++++++
xen/include/public/trace.h | 7 +++++
3 files changed, 73 insertions(+)
diff --git a/xen/Kconfig.debug b/xen/Kconfig.debug
index fd5cccc..4979e83 100644
--- a/xen/Kconfig.debug
+++ b/xen/Kconfig.debug
@@ -124,6 +124,14 @@ config TRACE_RCU
Makes it possible generate events showing the activity and the
behavior of the RCU subsystem.
+config TRACE_SOFTIRQS
+ bool "Trace when softirqs are raised and handled" if EXPERT = "y"
+ default n
+ depends on TRACING
+ ---help---
+ Makes it possible to generate events related to raising and
+ handling of softirqs within Xen.
+
config VERBOSE_DEBUG
bool "Verbose debug messages"
default DEBUG
diff --git a/xen/common/softirq.c b/xen/common/softirq.c
index 67c84ba..152788a 100644
--- a/xen/common/softirq.c
+++ b/xen/common/softirq.c
@@ -13,6 +13,7 @@
#include <xen/mm.h>
#include <xen/preempt.h>
#include <xen/sched.h>
+#include <xen/trace.h>
#include <xen/rcupdate.h>
#include <xen/softirq.h>
@@ -25,6 +26,57 @@ static softirq_handler softirq_handlers[NR_SOFTIRQS];
static DEFINE_PER_CPU(cpumask_t, batch_mask);
static DEFINE_PER_CPU(unsigned int, batching);
+#ifdef CONFIG_TRACE_SOFTIRQS
+#define trace_raise(n) TRACE_1D(TRC_XEN_SIRQ_RAISE, n)
+static inline void trace_raise_cpu(unsigned int nr, unsigned int cpu)
+{
+ struct {
+ uint16_t cpu, nr;
+ } d;
+
+ if ( likely(!tb_init_done) )
+ return;
+
+ d.nr = nr;
+ d.cpu = cpu;
+ __trace_var(TRC_XEN_SIRQ_RAISE_CPU, 1, sizeof(d), &d);
+}
+static inline
+void trace_raise_mask(unsigned int nr, const cpumask_t *m)
+{
+ struct {
+ uint32_t nr;
+ uint32_t mask[6];
+ } d;
+
+ if ( likely(!tb_init_done) )
+ return;
+
+ d.nr = nr;
+ memset(d.mask, 0, sizeof(d.mask));
+ memcpy(d.mask, m, min(sizeof(d.mask), sizeof(cpumask_t)));
+ __trace_var(TRC_XEN_SIRQ_RAISE_MASK, 1, sizeof(d), &d);
+}
+static inline void trace_handler(unsigned int nr, unsigned int cpu)
+{
+ struct {
+ uint16_t pending, nr;
+ } d;
+
+ if ( likely(!tb_init_done) )
+ return;
+
+ d.nr = nr;
+ d.pending = (uint16_t)softirq_pending(cpu);
+ __trace_var(TRC_XEN_SIRQ_HANDLER, 1, sizeof(d), &d);
+}
+#else /* !TRACE_SOFTIRQS */
+#define trace_raise(n) do {} while ( 0 )
+#define trace_raise_cpu(n, c) do {} while ( 0 )
+#define trace_raise_mask(n, m) do {} while ( 0 )
+#define trace_handler(n, c) do {} while ( 0 )
+#endif /* TRACE_SOFTIRQS */
+
static void __do_softirq(unsigned long ignore_mask)
{
unsigned int i, cpu = smp_processor_id();
@@ -43,6 +95,7 @@ static void __do_softirq(unsigned long ignore_mask)
i = find_first_set_bit(pending);
clear_bit(i, &softirq_pending(cpu));
+ trace_handler(i, cpu);
(*softirq_handlers[i])();
}
}
@@ -71,6 +124,8 @@ void cpumask_raise_softirq(const cpumask_t *mask, unsigned int nr)
unsigned int cpu, this_cpu = smp_processor_id();
cpumask_t send_mask, *raise_mask;
+ trace_raise_mask(nr, mask);
+
if ( !per_cpu(batching, this_cpu) || in_irq() )
{
cpumask_clear(&send_mask);
@@ -93,6 +148,8 @@ void cpu_raise_softirq(unsigned int cpu, unsigned int nr)
{
unsigned int this_cpu = smp_processor_id();
+ trace_raise_cpu(nr, cpu);
+
if ( test_and_set_bit(nr, &softirq_pending(cpu))
|| (cpu == this_cpu)
|| arch_skip_send_event_check(cpu) )
@@ -125,6 +182,7 @@ void cpu_raise_softirq_batch_finish(void)
void raise_softirq(unsigned int nr)
{
+ trace_raise(nr);
set_bit(nr, &softirq_pending(smp_processor_id()));
}
diff --git a/xen/include/public/trace.h b/xen/include/public/trace.h
index 50b4fcc..9d065aa 100644
--- a/xen/include/public/trace.h
+++ b/xen/include/public/trace.h
@@ -95,6 +95,7 @@
/* Trace subclasses for Xen internals */
#define TRC_XEN_RCU 0x01001000 /* RCU traces */
+#define TRC_XEN_SIRQ 0x01002000 /* Traces relating to softirqs */
/* Trace events per class */
#define TRC_LOST_RECORDS (TRC_GEN + 1)
@@ -292,6 +293,12 @@
#define TRC_XEN_RCU_DO_CALLBKS (TRC_XEN_RCU + 0x7)
#define TRC_XEN_RCU_PENDING (TRC_XEN_RCU + 0x8)
+/* Trace events for softirqs */
+#define TRC_XEN_SIRQ_HANDLER (TRC_XEN_SIRQ + 0x1)
+#define TRC_XEN_SIRQ_RAISE_MASK (TRC_XEN_SIRQ + 0x2)
+#define TRC_XEN_SIRQ_RAISE_CPU (TRC_XEN_SIRQ + 0x3)
+#define TRC_XEN_SIRQ_RAISE (TRC_XEN_SIRQ + 0x4)
+
/*
* Event Flags
*
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next prev parent reply other threads:[~2017-06-01 17:34 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-01 17:33 [PATCH 00/15] xen/tools: add tracing to various Xen subsystems Dario Faggioli
2017-06-01 17:33 ` [PATCH 01/15] xen: in do_softirq() sample smp_processor_id() once and for all Dario Faggioli
2017-06-07 14:38 ` Jan Beulich
2017-06-08 14:12 ` George Dunlap
2017-06-08 14:20 ` George Dunlap
2017-06-08 14:42 ` Jan Beulich
2017-06-01 17:33 ` [PATCH 02/15] xen: tracing: avoid checking tb_init_done multiple times Dario Faggioli
2017-06-01 17:53 ` Andrew Cooper
2017-06-01 23:08 ` Dario Faggioli
2017-06-07 14:46 ` Jan Beulich
2017-06-07 15:55 ` Dario Faggioli
2017-06-07 16:06 ` Jan Beulich
2017-06-08 14:34 ` George Dunlap
2017-06-08 14:37 ` George Dunlap
2017-06-01 17:33 ` [PATCH 03/15] xen/tools: tracing: several improvements on IRQs tracing Dario Faggioli
2017-06-01 18:02 ` Andrew Cooper
2017-06-01 23:12 ` Dario Faggioli
2017-06-07 15:05 ` Jan Beulich
2017-06-07 15:45 ` Dario Faggioli
2017-06-07 15:58 ` Jan Beulich
2017-06-08 14:53 ` George Dunlap
2017-06-08 15:34 ` Jan Beulich
2017-06-08 14:59 ` George Dunlap
2017-06-01 17:34 ` [PATCH 04/15] tools: xenalyze: fix dumping of PM_IDLE events Dario Faggioli
2017-06-08 15:06 ` George Dunlap
2017-06-01 17:34 ` [PATCH 05/15] xen: make it possible to disable tracing in Kconfig Dario Faggioli
2017-06-01 18:43 ` Andrew Cooper
2017-06-07 11:01 ` Julien Grall
2017-06-07 15:14 ` Jan Beulich
2017-06-08 15:16 ` George Dunlap
2017-06-08 15:35 ` Jan Beulich
2017-06-08 15:37 ` George Dunlap
2017-06-08 15:44 ` Jan Beulich
2017-06-08 15:17 ` George Dunlap
2017-06-01 17:34 ` [PATCH 06/15] xen: trace IRQ enabling/disabling Dario Faggioli
2017-06-01 19:08 ` Andrew Cooper
2017-06-01 23:42 ` Dario Faggioli
2017-06-08 15:51 ` George Dunlap
2017-06-08 16:05 ` Jan Beulich
2017-06-07 11:16 ` Julien Grall
2017-06-07 15:22 ` Dario Faggioli
2017-06-09 10:51 ` Julien Grall
2017-06-09 10:53 ` Julien Grall
2017-06-09 10:55 ` George Dunlap
2017-06-09 11:00 ` Julien Grall
2017-06-08 16:01 ` George Dunlap
2017-06-08 16:11 ` Dario Faggioli
2017-06-09 10:41 ` Jan Beulich
2017-06-01 17:34 ` [PATCH 07/15] tools: tracing: handle IRQs on/off events in xentrace and xenalyze Dario Faggioli
2017-06-13 15:58 ` George Dunlap
2017-06-01 17:34 ` [PATCH 08/15] xen: trace RCU behavior Dario Faggioli
2017-06-09 10:48 ` Jan Beulich
2017-06-13 16:05 ` George Dunlap
2017-06-01 17:34 ` [PATCH 09/15] tools: tracing: handle RCU events in xentrace and xenalyze Dario Faggioli
2017-06-13 16:12 ` George Dunlap
2017-06-01 17:34 ` Dario Faggioli [this message]
2017-06-09 10:51 ` [PATCH 10/15] xen: trace softirqs Jan Beulich
2017-06-01 17:34 ` [PATCH 11/15] tools: tracing: handle RCU events in xentrace and xenalyze Dario Faggioli
2017-06-01 17:35 ` [PATCH 12/15] xen: trace tasklets Dario Faggioli
2017-06-09 10:59 ` Jan Beulich
2017-06-09 11:17 ` Dario Faggioli
2017-06-09 11:29 ` Jan Beulich
2017-06-01 17:35 ` [PATCH 13/15] tools: tracing: handle tasklets events in xentrace and xenalyze Dario Faggioli
2017-06-01 17:35 ` [PATCH 14/15] xen: trace timers Dario Faggioli
2017-06-01 17:35 ` [PATCH 15/15] tools: tracing: handle timers events in xentrace and xenalyze Dario Faggioli
2017-06-07 14:13 ` [PATCH 00/15] xen/tools: add tracing to various Xen subsystems Konrad Rzeszutek Wilk
2017-06-08 16:45 ` Dario Faggioli
2017-06-13 16:34 ` George Dunlap
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