Revision 7f453c24b95a085fc7bd35d53b33abc4dc5a048b authored by Peter Zijlstra on 21 July 2009, 11:19:40 UTC, committed by Peter Zijlstra on 22 July 2009, 16:05:56 UTC
Anton noted that for inherited counters the counter-id as provided by
PERF_SAMPLE_ID isn't mappable to the id found through PERF_RECORD_ID
because each inherited counter gets its own id.

His suggestion was to always return the parent counter id, since that
is the primary counter id as exposed. However, these inherited
counters have a unique identifier so that events like
PERF_EVENT_PERIOD and PERF_EVENT_THROTTLE can be specific about which
counter gets modified, which is important when trying to normalize the
sample streams.

This patch removes PERF_EVENT_PERIOD in favour of PERF_SAMPLE_PERIOD,
which is more useful anyway, since changing periods became a lot more
common than initially thought -- rendering PERF_EVENT_PERIOD the less
useful solution (also, PERF_SAMPLE_PERIOD reports the more accurate
value, since it reports the value used to trigger the overflow,
whereas PERF_EVENT_PERIOD simply reports the requested period changed,
which might only take effect on the next cycle).

This still leaves us PERF_EVENT_THROTTLE to consider, but since that
_should_ be a rare occurrence, and linking it to a primary id is the
most useful bit to diagnose the problem, we introduce a
PERF_SAMPLE_STREAM_ID, for those few cases where the full
reconstruction is important.

[Does change the ABI a little, but I see no other way out]

Suggested-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1248095846.15751.8781.camel@twins>
1 parent 573402d
Raw File
debugfs_sta.c
/*
 * Copyright 2003-2005	Devicescape Software, Inc.
 * Copyright (c) 2006	Jiri Benc <jbenc@suse.cz>
 * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/debugfs.h>
#include <linux/ieee80211.h>
#include "ieee80211_i.h"
#include "debugfs.h"
#include "debugfs_sta.h"
#include "sta_info.h"

/* sta attributtes */

#define STA_READ(name, buflen, field, format_string)			\
static ssize_t sta_ ##name## _read(struct file *file,			\
				   char __user *userbuf,		\
				   size_t count, loff_t *ppos)		\
{									\
	int res;							\
	struct sta_info *sta = file->private_data;			\
	char buf[buflen];						\
	res = scnprintf(buf, buflen, format_string, sta->field);	\
	return simple_read_from_buffer(userbuf, count, ppos, buf, res);	\
}
#define STA_READ_D(name, field) STA_READ(name, 20, field, "%d\n")
#define STA_READ_U(name, field) STA_READ(name, 20, field, "%u\n")
#define STA_READ_LU(name, field) STA_READ(name, 20, field, "%lu\n")
#define STA_READ_S(name, field) STA_READ(name, 20, field, "%s\n")

#define STA_OPS(name)							\
static const struct file_operations sta_ ##name## _ops = {		\
	.read = sta_##name##_read,					\
	.open = mac80211_open_file_generic,				\
}

#define STA_FILE(name, field, format)					\
		STA_READ_##format(name, field)				\
		STA_OPS(name)

STA_FILE(aid, sta.aid, D);
STA_FILE(dev, sdata->dev->name, S);
STA_FILE(rx_packets, rx_packets, LU);
STA_FILE(tx_packets, tx_packets, LU);
STA_FILE(rx_bytes, rx_bytes, LU);
STA_FILE(tx_bytes, tx_bytes, LU);
STA_FILE(rx_duplicates, num_duplicates, LU);
STA_FILE(rx_fragments, rx_fragments, LU);
STA_FILE(rx_dropped, rx_dropped, LU);
STA_FILE(tx_fragments, tx_fragments, LU);
STA_FILE(tx_filtered, tx_filtered_count, LU);
STA_FILE(tx_retry_failed, tx_retry_failed, LU);
STA_FILE(tx_retry_count, tx_retry_count, LU);
STA_FILE(last_signal, last_signal, D);
STA_FILE(last_qual, last_qual, D);
STA_FILE(last_noise, last_noise, D);
STA_FILE(wep_weak_iv_count, wep_weak_iv_count, LU);

static ssize_t sta_flags_read(struct file *file, char __user *userbuf,
			      size_t count, loff_t *ppos)
{
	char buf[100];
	struct sta_info *sta = file->private_data;
	u32 staflags = get_sta_flags(sta);
	int res = scnprintf(buf, sizeof(buf), "%s%s%s%s%s%s%s%s",
		staflags & WLAN_STA_AUTH ? "AUTH\n" : "",
		staflags & WLAN_STA_ASSOC ? "ASSOC\n" : "",
		staflags & WLAN_STA_PS ? "PS\n" : "",
		staflags & WLAN_STA_AUTHORIZED ? "AUTHORIZED\n" : "",
		staflags & WLAN_STA_SHORT_PREAMBLE ? "SHORT PREAMBLE\n" : "",
		staflags & WLAN_STA_WME ? "WME\n" : "",
		staflags & WLAN_STA_WDS ? "WDS\n" : "",
		staflags & WLAN_STA_MFP ? "MFP\n" : "");
	return simple_read_from_buffer(userbuf, count, ppos, buf, res);
}
STA_OPS(flags);

static ssize_t sta_num_ps_buf_frames_read(struct file *file,
					  char __user *userbuf,
					  size_t count, loff_t *ppos)
{
	char buf[20];
	struct sta_info *sta = file->private_data;
	int res = scnprintf(buf, sizeof(buf), "%u\n",
			    skb_queue_len(&sta->ps_tx_buf));
	return simple_read_from_buffer(userbuf, count, ppos, buf, res);
}
STA_OPS(num_ps_buf_frames);

static ssize_t sta_inactive_ms_read(struct file *file, char __user *userbuf,
				    size_t count, loff_t *ppos)
{
	char buf[20];
	struct sta_info *sta = file->private_data;
	int res = scnprintf(buf, sizeof(buf), "%d\n",
			    jiffies_to_msecs(jiffies - sta->last_rx));
	return simple_read_from_buffer(userbuf, count, ppos, buf, res);
}
STA_OPS(inactive_ms);

static ssize_t sta_last_seq_ctrl_read(struct file *file, char __user *userbuf,
				      size_t count, loff_t *ppos)
{
	char buf[15*NUM_RX_DATA_QUEUES], *p = buf;
	int i;
	struct sta_info *sta = file->private_data;
	for (i = 0; i < NUM_RX_DATA_QUEUES; i++)
		p += scnprintf(p, sizeof(buf)+buf-p, "%x ",
			       le16_to_cpu(sta->last_seq_ctrl[i]));
	p += scnprintf(p, sizeof(buf)+buf-p, "\n");
	return simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
}
STA_OPS(last_seq_ctrl);

static ssize_t sta_agg_status_read(struct file *file, char __user *userbuf,
					size_t count, loff_t *ppos)
{
	char buf[768], *p = buf;
	int i;
	struct sta_info *sta = file->private_data;
	p += scnprintf(p, sizeof(buf)+buf-p, "Agg state for STA is:\n");
	p += scnprintf(p, sizeof(buf)+buf-p, " STA next dialog_token is %d \n "
			"TIDs info is: \n TID :",
			(sta->ampdu_mlme.dialog_token_allocator + 1));
	for (i = 0; i < STA_TID_NUM; i++)
		p += scnprintf(p, sizeof(buf)+buf-p, "%5d", i);

	p += scnprintf(p, sizeof(buf)+buf-p, "\n RX  :");
	for (i = 0; i < STA_TID_NUM; i++)
		p += scnprintf(p, sizeof(buf)+buf-p, "%5d",
			sta->ampdu_mlme.tid_state_rx[i]);

	p += scnprintf(p, sizeof(buf)+buf-p, "\n DTKN:");
	for (i = 0; i < STA_TID_NUM; i++)
		p += scnprintf(p, sizeof(buf)+buf-p, "%5d",
			sta->ampdu_mlme.tid_state_rx[i] ?
			sta->ampdu_mlme.tid_rx[i]->dialog_token : 0);

	p += scnprintf(p, sizeof(buf)+buf-p, "\n TX  :");
	for (i = 0; i < STA_TID_NUM; i++)
		p += scnprintf(p, sizeof(buf)+buf-p, "%5d",
			sta->ampdu_mlme.tid_state_tx[i]);

	p += scnprintf(p, sizeof(buf)+buf-p, "\n DTKN:");
	for (i = 0; i < STA_TID_NUM; i++)
		p += scnprintf(p, sizeof(buf)+buf-p, "%5d",
			sta->ampdu_mlme.tid_state_tx[i] ?
			sta->ampdu_mlme.tid_tx[i]->dialog_token : 0);

	p += scnprintf(p, sizeof(buf)+buf-p, "\n SSN :");
	for (i = 0; i < STA_TID_NUM; i++)
		p += scnprintf(p, sizeof(buf)+buf-p, "%5d",
			sta->ampdu_mlme.tid_state_tx[i] ?
			sta->ampdu_mlme.tid_tx[i]->ssn : 0);

	p += scnprintf(p, sizeof(buf)+buf-p, "\n");

	return simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
}
STA_OPS(agg_status);

#define DEBUGFS_ADD(name) \
	sta->debugfs.name = debugfs_create_file(#name, 0400, \
		sta->debugfs.dir, sta, &sta_ ##name## _ops);

#define DEBUGFS_DEL(name) \
	debugfs_remove(sta->debugfs.name);\
	sta->debugfs.name = NULL;


void ieee80211_sta_debugfs_add(struct sta_info *sta)
{
	struct dentry *stations_dir = sta->local->debugfs.stations;
	u8 mac[3*ETH_ALEN];

	sta->debugfs.add_has_run = true;

	if (!stations_dir)
		return;

	snprintf(mac, sizeof(mac), "%pM", sta->sta.addr);

	/*
	 * This might fail due to a race condition:
	 * When mac80211 unlinks a station, the debugfs entries
	 * remain, but it is already possible to link a new
	 * station with the same address which triggers adding
	 * it to debugfs; therefore, if the old station isn't
	 * destroyed quickly enough the old station's debugfs
	 * dir might still be around.
	 */
	sta->debugfs.dir = debugfs_create_dir(mac, stations_dir);
	if (!sta->debugfs.dir)
		return;

	DEBUGFS_ADD(flags);
	DEBUGFS_ADD(num_ps_buf_frames);
	DEBUGFS_ADD(inactive_ms);
	DEBUGFS_ADD(last_seq_ctrl);
	DEBUGFS_ADD(agg_status);
}

void ieee80211_sta_debugfs_remove(struct sta_info *sta)
{
	DEBUGFS_DEL(flags);
	DEBUGFS_DEL(num_ps_buf_frames);
	DEBUGFS_DEL(inactive_ms);
	DEBUGFS_DEL(last_seq_ctrl);
	DEBUGFS_DEL(agg_status);

	debugfs_remove(sta->debugfs.dir);
	sta->debugfs.dir = NULL;
}
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