[lttng-dev] [MODULES PATCH] irqsoff and preemptoff contexts

Mathieu Desnoyers mathieu.desnoyers at efficios.com
Wed Nov 11 08:51:10 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" ?

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(&lttng_static_ctx);
> +	if (ret) {
> +		printk(KERN_WARNING "Cannot add context lttng_add_irqsoff_to_ctx");
> +	}
> +	ret = lttng_add_preemptoff_to_ctx(&lttng_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



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