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
iw_stats.c
/*
 * Copyright (c) 2006 Oracle.  All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */
#include <linux/percpu.h>
#include <linux/seq_file.h>
#include <linux/proc_fs.h>

#include "rds.h"
#include "iw.h"

DEFINE_PER_CPU(struct rds_iw_statistics, rds_iw_stats) ____cacheline_aligned;

static char *rds_iw_stat_names[] = {
	"iw_connect_raced",
	"iw_listen_closed_stale",
	"iw_tx_cq_call",
	"iw_tx_cq_event",
	"iw_tx_ring_full",
	"iw_tx_throttle",
	"iw_tx_sg_mapping_failure",
	"iw_tx_stalled",
	"iw_tx_credit_updates",
	"iw_rx_cq_call",
	"iw_rx_cq_event",
	"iw_rx_ring_empty",
	"iw_rx_refill_from_cq",
	"iw_rx_refill_from_thread",
	"iw_rx_alloc_limit",
	"iw_rx_credit_updates",
	"iw_ack_sent",
	"iw_ack_send_failure",
	"iw_ack_send_delayed",
	"iw_ack_send_piggybacked",
	"iw_ack_received",
	"iw_rdma_mr_alloc",
	"iw_rdma_mr_free",
	"iw_rdma_mr_used",
	"iw_rdma_mr_pool_flush",
	"iw_rdma_mr_pool_wait",
	"iw_rdma_mr_pool_depleted",
};

unsigned int rds_iw_stats_info_copy(struct rds_info_iterator *iter,
				    unsigned int avail)
{
	struct rds_iw_statistics stats = {0, };
	uint64_t *src;
	uint64_t *sum;
	size_t i;
	int cpu;

	if (avail < ARRAY_SIZE(rds_iw_stat_names))
		goto out;

	for_each_online_cpu(cpu) {
		src = (uint64_t *)&(per_cpu(rds_iw_stats, cpu));
		sum = (uint64_t *)&stats;
		for (i = 0; i < sizeof(stats) / sizeof(uint64_t); i++)
			*(sum++) += *(src++);
	}

	rds_stats_info_copy(iter, (uint64_t *)&stats, rds_iw_stat_names,
			    ARRAY_SIZE(rds_iw_stat_names));
out:
	return ARRAY_SIZE(rds_iw_stat_names);
}
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