[lttng-dev] [MODULES PATCH] irqsoff and preemptoff contexts
Julien Desfossez
jdesfossez at efficios.com
Wed Nov 11 11:00:49 EST 2015
> irqsoff and preemptoff as names seems to imply a double negation.
>
> Could we make it so that "1" means "enabled" instead of "off" ?
I was thinking of those as flags, so they would be raised when the IRQs
or preemption is disabled. From my quick test with -k -a, they are at 0
most of the time.
I agree it is a double negation, I'm just not sure which option is the
clearest for the users.
Julien
>
> We should also add "need resched" thread flag.
>
> Thanks,
>
> Mathieu
>
> ----- On Nov 10, 2015, at 9:20 PM, Julien Desfossez jdesfossez at efficios.com wrote:
>
> > Signed-off-by: Julien Desfossez <jdesfossez at efficios.com>
> > ---
> > Makefile | 1 +
> > lttng-abi.c | 4 ++
> > lttng-abi.h | 2 +
> > lttng-context-irqsoff.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++
> > lttng-context-preemptoff.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++
> > lttng-context.c | 8 ++++
> > lttng-events.h | 2 +
> > 7 files changed, 205 insertions(+)
> > create mode 100644 lttng-context-irqsoff.c
> > create mode 100644 lttng-context-preemptoff.c
> >
> > diff --git a/Makefile b/Makefile
> > index f7aa23f..efc534e 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -41,6 +41,7 @@ lttng-tracer-objs := lttng-events.o lttng-abi.o \
> > lttng-context-vpid.o lttng-context-tid.o \
> > lttng-context-vtid.o lttng-context-ppid.o \
> > lttng-context-vppid.o lttng-context-cpu-id.o \
> > + lttng-context-irqsoff.o lttng-context-preemptoff.o \
> > lttng-calibrate.o \
> > lttng-context-hostname.o wrapper/random.o \
> > probes/lttng.o wrapper/trace-clock.o \
> > diff --git a/lttng-abi.c b/lttng-abi.c
> > index f6f3043..8be9b1e 100644
> > --- a/lttng-abi.c
> > +++ b/lttng-abi.c
> > @@ -236,6 +236,10 @@ long lttng_abi_add_context(struct file *file,
> > return lttng_add_hostname_to_ctx(ctx);
> > case LTTNG_KERNEL_CONTEXT_CPU_ID:
> > return lttng_add_cpu_id_to_ctx(ctx);
> > + case LTTNG_KERNEL_CONTEXT_IRQSOFF:
> > + return lttng_add_irqsoff_to_ctx(ctx);
> > + case LTTNG_KERNEL_CONTEXT_PREEMPTOFF:
> > + return lttng_add_preemptoff_to_ctx(ctx);
> > default:
> > return -EINVAL;
> > }
> > diff --git a/lttng-abi.h b/lttng-abi.h
> > index a40b58f..e8b0647 100644
> > --- a/lttng-abi.h
> > +++ b/lttng-abi.h
> > @@ -142,6 +142,8 @@ enum lttng_kernel_context_type {
> > LTTNG_KERNEL_CONTEXT_VPPID = 9,
> > LTTNG_KERNEL_CONTEXT_HOSTNAME = 10,
> > LTTNG_KERNEL_CONTEXT_CPU_ID = 11,
> > + LTTNG_KERNEL_CONTEXT_IRQSOFF = 12,
> > + LTTNG_KERNEL_CONTEXT_PREEMPTOFF = 13,
> > };
> >
> > struct lttng_kernel_perf_counter_ctx {
> > diff --git a/lttng-context-irqsoff.c b/lttng-context-irqsoff.c
> > new file mode 100644
> > index 0000000..2980265
> > --- /dev/null
> > +++ b/lttng-context-irqsoff.c
> > @@ -0,0 +1,94 @@
> > +/*
> > + * lttng-context-irqsoff.c
> > + *
> > + * LTTng irqsoff context.
> > + *
> > + * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
> > + *
> > + * This library is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU Lesser General Public
> > + * License as published by the Free Software Foundation; only
> > + * version 2.1 of the License.
> > + *
> > + * This library is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> > + * Lesser General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU Lesser General Public
> > + * License along with this library; if not, write to the Free Software
> > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> > + */
> > +
> > +#include <linux/module.h>
> > +#include <linux/slab.h>
> > +#include <linux/sched.h>
> > +#include <linux/irqflags.h>
> > +#include "lttng-events.h"
> > +#include "wrapper/ringbuffer/frontend_types.h"
> > +#include "wrapper/vmalloc.h"
> > +#include "lttng-tracer.h"
> > +
> > +static
> > +size_t irqsoff_get_size(size_t offset)
> > +{
> > + size_t size = 0;
> > +
> > + size += lib_ring_buffer_align(offset, lttng_alignof(uint8_t));
> > + size += sizeof(uint8_t);
> > + return size;
> > +}
> > +
> > +static
> > +void irqsoff_record(struct lttng_ctx_field *field,
> > + struct lib_ring_buffer_ctx *ctx,
> > + struct lttng_channel *chan)
> > +{
> > + uint8_t irqsoff = irqs_disabled();
> > +
> > + lib_ring_buffer_align_ctx(ctx, lttng_alignof(irqsoff));
> > + chan->ops->event_write(ctx, &irqsoff, sizeof(irqsoff));
> > +}
> > +
> > +static
> > +void irqsoff_get_value(struct lttng_ctx_field *field,
> > + union lttng_ctx_value *value)
> > +{
> > + value->s64 = irqs_disabled();
> > +}
> > +
> > +int lttng_add_irqsoff_to_ctx(struct lttng_ctx **ctx)
> > +{
> > + struct lttng_ctx_field *field;
> > +
> > + field = lttng_append_context(ctx);
> > + if (!field)
> > + return -ENOMEM;
> > + if (lttng_find_context(*ctx, "irqsoff")) {
> > + lttng_remove_context_field(ctx, field);
> > + return -EEXIST;
> > + }
> > + field->event_field.name = "irqsoff";
> > + field->event_field.type.atype = atype_integer;
> > + field->event_field.type.u.basic.integer.size = sizeof(uint8_t) * CHAR_BIT;
> > + field->event_field.type.u.basic.integer.alignment = lttng_alignof(uint8_t) *
> > CHAR_BIT;
> > + field->event_field.type.u.basic.integer.signedness =
> > lttng_is_signed_type(uint8_t);
> > + field->event_field.type.u.basic.integer.reverse_byte_order = 0;
> > + field->event_field.type.u.basic.integer.base = 10;
> > + field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
> > + field->get_size = irqsoff_get_size;
> > + field->record = irqsoff_record;
> > + field->get_value = irqsoff_get_value;
> > + lttng_context_update(*ctx);
> > + wrapper_vmalloc_sync_all();
> > + return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(lttng_add_irqsoff_to_ctx);
> > +
> > +MODULE_LICENSE("GPL and additional rights");
> > +MODULE_AUTHOR("Mathieu Desnoyers");
> > +MODULE_DESCRIPTION("Linux Trace Toolkit irqsoff Context");
> > +MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
> > + __stringify(LTTNG_MODULES_MINOR_VERSION) "."
> > + __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
> > + LTTNG_MODULES_EXTRAVERSION);
> > diff --git a/lttng-context-preemptoff.c b/lttng-context-preemptoff.c
> > new file mode 100644
> > index 0000000..72d60f8
> > --- /dev/null
> > +++ b/lttng-context-preemptoff.c
> > @@ -0,0 +1,94 @@
> > +/*
> > + * lttng-context-preemptoff.c
> > + *
> > + * LTTng preemptoff context.
> > + *
> > + * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
> > + *
> > + * This library is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU Lesser General Public
> > + * License as published by the Free Software Foundation; only
> > + * version 2.1 of the License.
> > + *
> > + * This library is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> > + * Lesser General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU Lesser General Public
> > + * License along with this library; if not, write to the Free Software
> > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> > + */
> > +
> > +#include <linux/module.h>
> > +#include <linux/slab.h>
> > +#include <linux/sched.h>
> > +#include <linux/irqflags.h>
> > +#include "lttng-events.h"
> > +#include "wrapper/ringbuffer/frontend_types.h"
> > +#include "wrapper/vmalloc.h"
> > +#include "lttng-tracer.h"
> > +
> > +static
> > +size_t preemptoff_get_size(size_t offset)
> > +{
> > + size_t size = 0;
> > +
> > + size += lib_ring_buffer_align(offset, lttng_alignof(uint8_t));
> > + size += sizeof(uint8_t);
> > + return size;
> > +}
> > +
> > +static
> > +void preemptoff_record(struct lttng_ctx_field *field,
> > + struct lib_ring_buffer_ctx *ctx,
> > + struct lttng_channel *chan)
> > +{
> > + uint8_t preemptoff = !!preempt_count();
> > +
> > + lib_ring_buffer_align_ctx(ctx, lttng_alignof(preemptoff));
> > + chan->ops->event_write(ctx, &preemptoff, sizeof(preemptoff));
> > +}
> > +
> > +static
> > +void preemptoff_get_value(struct lttng_ctx_field *field,
> > + union lttng_ctx_value *value)
> > +{
> > + value->s64 = !!preempt_count();
> > +}
> > +
> > +int lttng_add_preemptoff_to_ctx(struct lttng_ctx **ctx)
> > +{
> > + struct lttng_ctx_field *field;
> > +
> > + field = lttng_append_context(ctx);
> > + if (!field)
> > + return -ENOMEM;
> > + if (lttng_find_context(*ctx, "preemptoff")) {
> > + lttng_remove_context_field(ctx, field);
> > + return -EEXIST;
> > + }
> > + field->event_field.name = "preemptoff";
> > + field->event_field.type.atype = atype_integer;
> > + field->event_field.type.u.basic.integer.size = sizeof(uint8_t) * CHAR_BIT;
> > + field->event_field.type.u.basic.integer.alignment = lttng_alignof(uint8_t) *
> > CHAR_BIT;
> > + field->event_field.type.u.basic.integer.signedness =
> > lttng_is_signed_type(uint8_t);
> > + field->event_field.type.u.basic.integer.reverse_byte_order = 0;
> > + field->event_field.type.u.basic.integer.base = 10;
> > + field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
> > + field->get_size = preemptoff_get_size;
> > + field->record = preemptoff_record;
> > + field->get_value = preemptoff_get_value;
> > + lttng_context_update(*ctx);
> > + wrapper_vmalloc_sync_all();
> > + return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(lttng_add_preemptoff_to_ctx);
> > +
> > +MODULE_LICENSE("GPL and additional rights");
> > +MODULE_AUTHOR("Mathieu Desnoyers");
> > +MODULE_DESCRIPTION("Linux Trace Toolkit preemptoff Context");
> > +MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
> > + __stringify(LTTNG_MODULES_MINOR_VERSION) "."
> > + __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
> > + LTTNG_MODULES_EXTRAVERSION);
> > diff --git a/lttng-context.c b/lttng-context.c
> > index eca58ce..66e828b 100644
> > --- a/lttng-context.c
> > +++ b/lttng-context.c
> > @@ -268,6 +268,14 @@ int lttng_context_init(void)
> > if (ret) {
> > printk(KERN_WARNING "Cannot add context lttng_add_cpu_id_to_ctx");
> > }
> > + ret = lttng_add_irqsoff_to_ctx(<tng_static_ctx);
> > + if (ret) {
> > + printk(KERN_WARNING "Cannot add context lttng_add_irqsoff_to_ctx");
> > + }
> > + ret = lttng_add_preemptoff_to_ctx(<tng_static_ctx);
> > + if (ret) {
> > + printk(KERN_WARNING "Cannot add context lttng_add_preemptoff_to_ctx");
> > + }
> > /* TODO: perf counters for filtering */
> > return 0;
> > }
> > diff --git a/lttng-events.h b/lttng-events.h
> > index 234d4bc..dda22e7 100644
> > --- a/lttng-events.h
> > +++ b/lttng-events.h
> > @@ -630,6 +630,8 @@ int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx);
> > int lttng_add_ppid_to_ctx(struct lttng_ctx **ctx);
> > int lttng_add_vppid_to_ctx(struct lttng_ctx **ctx);
> > int lttng_add_hostname_to_ctx(struct lttng_ctx **ctx);
> > +int lttng_add_irqsoff_to_ctx(struct lttng_ctx **ctx);
> > +int lttng_add_preemptoff_to_ctx(struct lttng_ctx **ctx);
> > #if defined(CONFIG_PERF_EVENTS) && (LINUX_VERSION_CODE >=
> > KERNEL_VERSION(2,6,33))
> > int lttng_add_perf_counter_to_ctx(uint32_t type,
> > uint64_t config,
> > --
> > 1.9.1
>
> --
> Mathieu Desnoyers
> EfficiOS Inc.
> http://www.efficios.com
>
> _______________________________________________
> lttng-dev mailing list
> lttng-dev at lists.lttng.org
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