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 <linux/export.h>

#include "rds.h"

DEFINE_PER_CPU_SHARED_ALIGNED(struct rds_statistics, rds_stats);
EXPORT_PER_CPU_SYMBOL_GPL(rds_stats);

/* :.,$s/unsigned long>.*<s_\(.*\);/"\1",/g */

static const char *const rds_stat_names[] = {
    "conn_reset",
    "recv_drop_bad_checksum",
    "recv_drop_old_seq",
    "recv_drop_no_sock",
    "recv_drop_dead_sock",
    "recv_deliver_raced",
    "recv_delivered",
    "recv_queued",
    "recv_immediate_retry",
    "recv_delayed_retry",
    "recv_ack_required",
    "recv_rdma_bytes",
    "recv_ping",
    "send_queue_empty",
    "send_queue_full",
    "send_lock_contention",
    "send_lock_queue_raced",
    "send_immediate_retry",
    "send_delayed_retry",
    "send_drop_acked",
    "send_ack_required",
    "send_queued",
    "send_rdma",
    "send_rdma_bytes",
    "send_pong",
    "page_remainder_hit",
    "page_remainder_miss",
    "copy_to_user",
    "copy_from_user",
    "cong_update_queued",
    "cong_update_received",
    "cong_send_error",
    "cong_send_blocked",
};

void rds_stats_info_copy(struct rds_info_iterator *iter,
             uint64_t *values, const char *const *names, size_t nr)
{
    struct rds_info_counter ctr;
    size_t i;

    for (i = 0; i < nr; i++) {
        BUG_ON(strlen(names[i]) >= sizeof(ctr.name));
        strncpy(ctr.name, names[i], sizeof(ctr.name) - 1);
        ctr.value = values[i];

        rds_info_copy(iter, &ctr, sizeof(ctr));
    }
}
EXPORT_SYMBOL_GPL(rds_stats_info_copy);

/*
 * This gives global counters across all the transports.  The strings
 * are copied in so that the tool doesn't need knowledge of the specific
 * stats that we're exporting.  Some are pretty implementation dependent
 * and may change over time.  That doesn't stop them from being useful.
 *
 * This is the only function in the chain that knows about the byte granular
 * length in userspace.  It converts it to number of stat entries that the
 * rest of the functions operate in.
 */
static void rds_stats_info(struct socket *sock, unsigned int len,
               struct rds_info_iterator *iter,
               struct rds_info_lengths *lens)
{
    struct rds_statistics stats = {0, };
    uint64_t *src;
    uint64_t *sum;
    size_t i;
    int cpu;
    unsigned int avail;

    avail = len / sizeof(struct rds_info_counter);

    if (avail < ARRAY_SIZE(rds_stat_names)) {
        avail = 0;
        goto trans;
    }

    for_each_online_cpu(cpu) {
        src = (uint64_t *)&(per_cpu(rds_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_stat_names,
                ARRAY_SIZE(rds_stat_names));
    avail -= ARRAY_SIZE(rds_stat_names);

trans:
    lens->each = sizeof(struct rds_info_counter);
    lens->nr = rds_trans_stats_info_copy(iter, avail) +
           ARRAY_SIZE(rds_stat_names);
}

void rds_stats_exit(void)
{
    rds_info_deregister_func(RDS_INFO_COUNTERS, rds_stats_info);
}

int rds_stats_init(void)
{
    rds_info_register_func(RDS_INFO_COUNTERS, rds_stats_info);
    return 0;
}