tcp_stats.c

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/*
 * 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 "tcp.h"

DEFINE_PER_CPU(struct rds_tcp_statistics, rds_tcp_stats)
    ____cacheline_aligned;

static const char * const rds_tcp_stat_names[] = {
    "tcp_data_ready_calls",
    "tcp_write_space_calls",
    "tcp_sndbuf_full",
    "tcp_connect_raced",
    "tcp_listen_closed_stale",
};

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

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

    for_each_online_cpu(cpu) {
        src = (uint64_t *)&(per_cpu(rds_tcp_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_tcp_stat_names,
                ARRAY_SIZE(rds_tcp_stat_names));
out:
    return ARRAY_SIZE(rds_tcp_stat_names);
}