Re: [PATCH] kmemtrace: Remove the relay version of kmemtrace.

[Frederic Weisbecker <fweisbec@gmail.com>]

On Mon, Jan 05, 2009 at 10:09:58PM +0200, Eduard - Gabriel Munteanu wrote:
> kmemtrace now uses ftrace. This patch removes the relay version.
> 
> Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
> ---
>  kernel/trace/Kconfig |    1 -
>  mm/Makefile          |    1 -
>  mm/kmemtrace.c       |  333 --------------------------------------------------
>  3 files changed, 0 insertions(+), 335 deletions(-)
>  delete mode 100644 mm/kmemtrace.c
> 
> diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
> index cc9f91e..4b69dd3 100644
> --- a/kernel/trace/Kconfig
> +++ b/kernel/trace/Kconfig
> @@ -268,7 +268,6 @@ config KMEMTRACE
>  	bool "Trace SLAB allocations"
>  	select TRACING
>  	select MARKERS
> -	select RELAY
>  	help
>  	  kmemtrace provides tracing for slab allocator functions, such as
>  	  kmalloc, kfree, kmem_cache_alloc, kmem_cache_free etc.. Collected
> diff --git a/mm/Makefile b/mm/Makefile
> index 1910665..33892d1 100644
> --- a/mm/Makefile
> +++ b/mm/Makefile
> @@ -36,4 +36,3 @@ obj-$(CONFIG_MIGRATION) += migrate.o
>  obj-$(CONFIG_SMP) += allocpercpu.o
>  obj-$(CONFIG_QUICKLIST) += quicklist.o
>  obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o page_cgroup.o
> -obj-$(CONFIG_KMEMTRACE) += kmemtrace.o
> diff --git a/mm/kmemtrace.c b/mm/kmemtrace.c
> deleted file mode 100644
> index 0573b50..0000000
> --- a/mm/kmemtrace.c
> +++ /dev/null
> @@ -1,333 +0,0 @@
> -/*
> - * Copyright (C) 2008 Pekka Enberg, Eduard - Gabriel Munteanu
> - *
> - * This file is released under GPL version 2.
> - */
> -
> -#include <linux/string.h>
> -#include <linux/debugfs.h>
> -#include <linux/relay.h>
> -#include <linux/module.h>
> -#include <linux/marker.h>
> -#include <linux/gfp.h>
> -#include <trace/kmemtrace.h>
> -
> -#define KMEMTRACE_SUBBUF_SIZE		524288
> -#define KMEMTRACE_DEF_N_SUBBUFS		20
> -
> -static struct rchan *kmemtrace_chan;
> -static u32 kmemtrace_buf_overruns;
> -
> -static unsigned int kmemtrace_n_subbufs;
> -
> -/* disabled by default */
> -static unsigned int kmemtrace_enabled;
> -
> -/*
> - * The sequence number is used for reordering kmemtrace packets
> - * in userspace, since they are logged as per-CPU data.
> - *
> - * atomic_t should always be a 32-bit signed integer. Wraparound is not
> - * likely to occur, but userspace can deal with it by expecting a certain
> - * sequence number in the next packet that will be read.
> - */
> -static atomic_t kmemtrace_seq_num;
> -
> -#define KMEMTRACE_ABI_VERSION		1
> -
> -static u32 kmemtrace_abi_version __read_mostly = KMEMTRACE_ABI_VERSION;
> -
> -enum kmemtrace_event_id {
> -	KMEMTRACE_EVENT_ALLOC = 0,
> -	KMEMTRACE_EVENT_FREE,
> -};
> -
> -struct kmemtrace_event {
> -	u8		event_id;
> -	u8		type_id;
> -	u16		event_size;
> -	s32		seq_num;
> -	u64		call_site;
> -	u64		ptr;
> -} __attribute__ ((__packed__));
> -
> -struct kmemtrace_stats_alloc {
> -	u64		bytes_req;
> -	u64		bytes_alloc;
> -	u32		gfp_flags;
> -	s32		numa_node;
> -} __attribute__ ((__packed__));
> -
> -static void kmemtrace_probe_alloc(void *probe_data, void *call_data,
> -				  const char *format, va_list *args)
> -{
> -	unsigned long flags;
> -	struct kmemtrace_event *ev;
> -	struct kmemtrace_stats_alloc *stats;
> -	void *buf;
> -
> -	local_irq_save(flags);
> -
> -	buf = relay_reserve(kmemtrace_chan,
> -			    sizeof(struct kmemtrace_event) +
> -			    sizeof(struct kmemtrace_stats_alloc));
> -	if (!buf)
> -		goto failed;
> -
> -	/*
> -	 * Don't convert this to use structure initializers,
> -	 * C99 does not guarantee the rvalues evaluation order.
> -	 */
> -
> -	ev = buf;
> -	ev->event_id = KMEMTRACE_EVENT_ALLOC;
> -	ev->type_id = va_arg(*args, int);
> -	ev->event_size = sizeof(struct kmemtrace_event) +
> -			 sizeof(struct kmemtrace_stats_alloc);
> -	ev->seq_num = atomic_add_return(1, &kmemtrace_seq_num);
> -	ev->call_site = va_arg(*args, unsigned long);
> -	ev->ptr = va_arg(*args, unsigned long);
> -
> -	stats = buf + sizeof(struct kmemtrace_event);
> -	stats->bytes_req = va_arg(*args, unsigned long);
> -	stats->bytes_alloc = va_arg(*args, unsigned long);
> -	stats->gfp_flags = va_arg(*args, unsigned long);
> -	stats->numa_node = va_arg(*args, int);
> -
> -failed:
> -	local_irq_restore(flags);
> -}
> -
> -static void kmemtrace_probe_free(void *probe_data, void *call_data,
> -				 const char *format, va_list *args)
> -{
> -	unsigned long flags;
> -	struct kmemtrace_event *ev;
> -
> -	local_irq_save(flags);
> -
> -	ev = relay_reserve(kmemtrace_chan, sizeof(struct kmemtrace_event));
> -	if (!ev)
> -		goto failed;
> -
> -	/*
> -	 * Don't convert this to use structure initializers,
> -	 * C99 does not guarantee the rvalues evaluation order.
> -	 */
> -	ev->event_id = KMEMTRACE_EVENT_FREE;
> -	ev->type_id = va_arg(*args, int);
> -	ev->event_size = sizeof(struct kmemtrace_event);
> -	ev->seq_num = atomic_add_return(1, &kmemtrace_seq_num);
> -	ev->call_site = va_arg(*args, unsigned long);
> -	ev->ptr = va_arg(*args, unsigned long);
> -
> -failed:
> -	local_irq_restore(flags);
> -}
> -
> -static struct dentry *
> -kmemtrace_create_buf_file(const char *filename, struct dentry *parent,
> -			  int mode, struct rchan_buf *buf, int *is_global)
> -{
> -	return debugfs_create_file(filename, mode, parent, buf,
> -				   &relay_file_operations);
> -}
> -
> -static int kmemtrace_remove_buf_file(struct dentry *dentry)
> -{
> -	debugfs_remove(dentry);
> -
> -	return 0;
> -}
> -
> -static int kmemtrace_subbuf_start(struct rchan_buf *buf,
> -				  void *subbuf,
> -				  void *prev_subbuf,
> -				  size_t prev_padding)
> -{
> -	if (relay_buf_full(buf)) {
> -		/*
> -		 * We know it's not SMP-safe, but neither
> -		 * debugfs_create_u32() is.
> -		 */
> -		kmemtrace_buf_overruns++;
> -		return 0;
> -	}
> -
> -	return 1;
> -}
> -
> -static struct rchan_callbacks relay_callbacks = {
> -	.create_buf_file = kmemtrace_create_buf_file,
> -	.remove_buf_file = kmemtrace_remove_buf_file,
> -	.subbuf_start = kmemtrace_subbuf_start,
> -};
> -
> -static struct dentry *kmemtrace_dir;
> -static struct dentry *kmemtrace_overruns_dentry;
> -static struct dentry *kmemtrace_abi_version_dentry;
> -
> -static struct dentry *kmemtrace_enabled_dentry;
> -
> -static int kmemtrace_start_probes(void)
> -{
> -	int err;
> -
> -	err = marker_probe_register("kmemtrace_alloc", "type_id %d "
> -				    "call_site %lu ptr %lu "
> -				    "bytes_req %lu bytes_alloc %lu "
> -				    "gfp_flags %lu node %d",
> -				    kmemtrace_probe_alloc, NULL);
> -	if (err)
> -		return err;
> -	err = marker_probe_register("kmemtrace_free", "type_id %d "
> -				    "call_site %lu ptr %lu",
> -				    kmemtrace_probe_free, NULL);
> -
> -	return err;
> -}
> -
> -static void kmemtrace_stop_probes(void)
> -{
> -	marker_probe_unregister("kmemtrace_alloc",
> -				kmemtrace_probe_alloc, NULL);
> -	marker_probe_unregister("kmemtrace_free",
> -				kmemtrace_probe_free, NULL);
> -}
> -
> -static int kmemtrace_enabled_get(void *data, u64 *val)
> -{
> -	*val = *((int *) data);
> -
> -	return 0;
> -}
> -
> -static int kmemtrace_enabled_set(void *data, u64 val)
> -{
> -	u64 old_val = kmemtrace_enabled;
> -
> -	*((int *) data) = !!val;
> -
> -	if (old_val == val)
> -		return 0;
> -	if (val)
> -		kmemtrace_start_probes();
> -	else
> -		kmemtrace_stop_probes();
> -
> -	return 0;
> -}
> -
> -DEFINE_SIMPLE_ATTRIBUTE(kmemtrace_enabled_fops,
> -			kmemtrace_enabled_get,
> -			kmemtrace_enabled_set, "%llu\n");
> -
> -static void kmemtrace_cleanup(void)
> -{
> -	if (kmemtrace_enabled_dentry)
> -		debugfs_remove(kmemtrace_enabled_dentry);
> -
> -	kmemtrace_stop_probes();
> -
> -	if (kmemtrace_abi_version_dentry)
> -		debugfs_remove(kmemtrace_abi_version_dentry);
> -	if (kmemtrace_overruns_dentry)
> -		debugfs_remove(kmemtrace_overruns_dentry);
> -
> -	relay_close(kmemtrace_chan);
> -	kmemtrace_chan = NULL;
> -
> -	if (kmemtrace_dir)
> -		debugfs_remove(kmemtrace_dir);
> -}
> -
> -static int __init kmemtrace_setup_late(void)
> -{
> -	if (!kmemtrace_chan)
> -		goto failed;
> -
> -	kmemtrace_dir = debugfs_create_dir("kmemtrace", NULL);
> -	if (!kmemtrace_dir)
> -		goto cleanup;
> -
> -	kmemtrace_abi_version_dentry =
> -		debugfs_create_u32("abi_version", S_IRUSR,
> -				   kmemtrace_dir, &kmemtrace_abi_version);
> -	kmemtrace_overruns_dentry =
> -		debugfs_create_u32("total_overruns", S_IRUSR,
> -				   kmemtrace_dir, &kmemtrace_buf_overruns);
> -	if (!kmemtrace_overruns_dentry || !kmemtrace_abi_version_dentry)
> -		goto cleanup;
> -
> -	kmemtrace_enabled_dentry =
> -		debugfs_create_file("enabled", S_IRUSR | S_IWUSR,
> -				    kmemtrace_dir, &kmemtrace_enabled,
> -				    &kmemtrace_enabled_fops);
> -	if (!kmemtrace_enabled_dentry)
> -		goto cleanup;
> -
> -	if (relay_late_setup_files(kmemtrace_chan, "cpu", kmemtrace_dir))
> -		goto cleanup;
> -
> -	printk(KERN_INFO "kmemtrace: fully up.\n");
> -
> -	return 0;
> -
> -cleanup:
> -	kmemtrace_cleanup();
> -failed:
> -	return 1;
> -}
> -late_initcall(kmemtrace_setup_late);
> -
> -static int __init kmemtrace_set_boot_enabled(char *str)
> -{
> -	if (!str)
> -		return -EINVAL;
> -
> -	if (!strcmp(str, "yes"))
> -		kmemtrace_enabled = 1;
> -	else if (!strcmp(str, "no"))
> -		kmemtrace_enabled = 0;
> -	else
> -		return -EINVAL;
> -
> -	return 0;
> -}
> -early_param("kmemtrace.enable", kmemtrace_set_boot_enabled);
> -
> -static int __init kmemtrace_set_subbufs(char *str)
> -{
> -	get_option(&str, &kmemtrace_n_subbufs);
> -	return 0;
> -}
> -early_param("kmemtrace.subbufs", kmemtrace_set_subbufs);
> -
> -void kmemtrace_init(void)
> -{
> -	if (!kmemtrace_n_subbufs)
> -		kmemtrace_n_subbufs = KMEMTRACE_DEF_N_SUBBUFS;
> -
> -	kmemtrace_chan = relay_open(NULL, NULL, KMEMTRACE_SUBBUF_SIZE,
> -				    kmemtrace_n_subbufs, &relay_callbacks,
> -				    NULL);
> -	if (!kmemtrace_chan) {
> -		printk(KERN_ERR "kmemtrace: could not open relay channel.\n");
> -		return;
> -	}
> -
> -	if (!kmemtrace_enabled) {
> -		printk(KERN_INFO "kmemtrace: disabled. Pass "
> -			"kemtrace.enable=yes as kernel parameter for "
> -			"boot-time tracing.\n");
> -		return;
> -	}
> -	if (kmemtrace_start_probes()) {
> -		printk(KERN_ERR "kmemtrace: could not register marker probes!\n");
> -		kmemtrace_cleanup();
> -		return;
> -	}
> -
> -	printk(KERN_INFO "kmemtrace: enabled.\n");
> -}
> -
> -- 
> 1.6.0.6
> 


BTW, I've kept the MARKERS dependency from the previous CONFIG entry of kmemtrace.
Looks like it is not needed anymore.
So I will drop it...