Merge branch 'develop'
[archipelago] / xseg / peers / user / bench-xseg.c
diff --git a/xseg/peers/user/bench-xseg.c b/xseg/peers/user/bench-xseg.c
new file mode 100644 (file)
index 0000000..f2be42e
--- /dev/null
@@ -0,0 +1,678 @@
+/*
+ * Copyright 2012 GRNET S.A. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ *   1. Redistributions of source code must retain the above
+ *      copyright notice, this list of conditions and the following
+ *      disclaimer.
+ *   2. 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * The views and conclusions contained in the software and
+ * documentation are those of the authors and should not be
+ * interpreted as representing official policies, either expressed
+ * or implied, of GRNET S.A.
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <pthread.h>
+#include <xseg/xseg.h>
+#include <peer.h>
+#include <time.h>
+#include <sys/util.h>
+#include <signal.h>
+#include <bench-xseg.h>
+#include <bench-lfsr.h>
+#include <limits.h>
+
+char global_id[IDLEN + 1];
+/*
+ * This macro checks two things:
+ * a) If in-flight requests are less than given iodepth
+ * b) If we have submitted all of the requests
+ */
+#define CAN_SEND_REQUEST(__p)                                                                                  \
+       ((__p->status->submitted - __p->status->received < __p->iodepth) && \
+       (__p->status->submitted < __p->status->max) &&                                          \
+       !isTerminate())
+
+#define CAN_VERIFY(__p)                                                                                                        \
+       ((GET_FLAG(VERIFY, __p->flags) != VERIFY_NO) && __p->op == X_READ)
+
+#define CAN_PRINT_PROGRESS(__p, __q)                                                                   \
+       ((GET_FLAG(PROGRESS, __p->flags) == PROGRESS_YES) &&                            \
+       (__p->status->received == __q))
+
+void custom_peer_usage()
+{
+       fprintf(stderr, "Custom peer options: \n"
+                       "  --------------------------------------------\n"
+                       "    -op       | None    | XSEG operation [read|write|info|delete]\n"
+                       "    --pattern | None    | I/O pattern [seq|rand]\n"
+                       "    --verify  | no      | Verify written requests [no|meta|full]\n"
+                       "    -rc       | None    | Request cap\n"
+                       "    -to       | None    | Total objects\n"
+                       "    -ts       | None    | Total I/O size\n"
+                       "    -os       | 4M      | Object size\n"
+                       "    -bs       | 4k      | Block size\n"
+                       "    -tp       | None    | Target port\n"
+                       "    --iodepth | 1       | Number of in-flight I/O requests\n"
+                       "    --seed    | None    | Initialize LFSR and target names\n"
+                       "    --insanity| sane    | Adjust insanity level of benchmark:\n"
+                       "              |         |     [sane|eccentric|manic|paranoid]\n"
+                       "    --progress| yes     | Show progress of requests\n"
+                       "\n"
+                       "Additional information:\n"
+                       "  --------------------------------------------\n"
+                       "  The -to and -ts options are mutually exclusive\n"
+                       "\n");
+}
+
+int custom_peer_init(struct peerd *peer, int argc, char *argv[])
+{
+       struct bench *prefs;
+       char request_cap[MAX_ARG_LEN + 1];
+       char total_objects[MAX_ARG_LEN + 1];
+       char total_size[MAX_ARG_LEN + 1];
+       char object_size[MAX_ARG_LEN + 1];
+       char block_size[MAX_ARG_LEN + 1];
+       char op[MAX_ARG_LEN + 1];
+       char pattern[MAX_ARG_LEN + 1];
+       char insanity[MAX_ARG_LEN + 1];
+       char verify[MAX_ARG_LEN + 1];
+       char progress[MAX_ARG_LEN + 1];
+       struct xseg *xseg = peer->xseg;
+       unsigned int xseg_page_size = 1 << xseg->config.page_shift;
+       long iodepth = -1;
+       long dst_port = -1;
+       unsigned long seed = -1;
+       uint64_t rc;
+       struct timespec timer_seed;
+       int set_by_hand = 0;
+       int r;
+
+       op[0] = 0;
+       pattern[0] = 0;
+       total_objects[0] = 0;
+       total_size[0] = 0;
+       block_size[0] = 0;
+       object_size[0] = 0;
+       insanity[0] = 0;
+       verify[0] = 0;
+       request_cap[0] = 0;
+       progress[0] = 0;
+
+#ifdef MT
+       for (i = 0; i < nr_threads; i++) {
+               prefs = peer->thread[i]->priv;
+               prefs = malloc(sizeof(struct bench));
+               if (!prefs) {
+                       perror("malloc");
+                       return -1;
+               }
+       }
+#endif
+       prefs = malloc(sizeof(struct bench));
+       if (!prefs) {
+               perror("malloc");
+               return -1;
+       }
+       memset(prefs, 0, sizeof(struct bench));
+
+       prefs->status = malloc(sizeof(struct req_status));
+       if (!prefs->status) {
+               perror("malloc");
+               return -1;
+       }
+
+       memset(prefs->status, 0, sizeof(struct req_status));
+
+       //Begin reading the benchmark-specific arguments
+       BEGIN_READ_ARGS(argc, argv);
+       READ_ARG_STRING("-rc", request_cap, MAX_ARG_LEN);
+       READ_ARG_STRING("-op", op, MAX_ARG_LEN);
+       READ_ARG_STRING("--pattern", pattern, MAX_ARG_LEN);
+       READ_ARG_STRING("-to", total_objects, MAX_ARG_LEN);
+       READ_ARG_STRING("-ts", total_size, MAX_ARG_LEN);
+       READ_ARG_STRING("-os", object_size, MAX_ARG_LEN);
+       READ_ARG_STRING("-bs", block_size, MAX_ARG_LEN);
+       READ_ARG_ULONG("--iodepth", iodepth);
+       READ_ARG_ULONG("-tp", dst_port);
+       READ_ARG_ULONG("--seed", seed);
+       READ_ARG_STRING("--insanity", insanity, MAX_ARG_LEN);
+       READ_ARG_STRING("--verify", verify, MAX_ARG_LEN);
+       READ_ARG_STRING("--progress", progress, MAX_ARG_LEN);
+       END_READ_ARGS();
+
+       /*****************************\
+        * Check I/O type parameters *
+       \*****************************/
+
+       //We support 4 xseg operations: X_READ, X_WRITE, X_DELETE, X_INFO
+       //The I/O pattern of these operations can be either sequential (seq) or
+       //random (rand)
+       if (!op[0]) {
+               XSEGLOG2(&lc, E, "xseg operation needs to be supplied\n");
+               goto arg_fail;
+       }
+       r = read_op(op);
+       if (r < 0) {
+               XSEGLOG2(&lc, E, "Invalid syntax: -op %s\n", op);
+               goto arg_fail;
+       }
+       prefs->op = r;
+
+       if (!pattern[0]) {
+               XSEGLOG2(&lc, E, "I/O pattern needs to be supplied\n");
+               goto arg_fail;
+       }
+       r = read_pattern(pattern);
+       if (r < 0) {
+               XSEGLOG2(&lc, E, "Invalid syntax: --pattern %s\n", pattern);
+               goto arg_fail;
+       }
+       SET_FLAG(PATTERN, prefs->flags, r);
+
+       if (!verify[0])
+               strcpy(verify, "no");
+       r = read_verify(verify);
+       if (r < 0) {
+               XSEGLOG2(&lc, E, "Invalid syntax: --verify %s\n", verify);
+               goto arg_fail;
+       }
+       SET_FLAG(VERIFY, prefs->flags, r);
+
+       //Default iodepth value is 1
+       if (iodepth < 0)
+               prefs->iodepth = 1;
+       else
+               prefs->iodepth = iodepth;
+
+       /**************************\
+        * Check timer parameters *
+       \**************************/
+
+       //Most of the times, not all timers need to be used.
+       //We can choose which timers will be used by adjusting the "insanity"
+       //level of the benchmark i.e. the obscurity of code paths (get request,
+       //submit request) that will be timed.
+       if (!insanity[0])
+               strcpy(insanity, "sane");
+
+       r = read_insanity(insanity);
+       if (r < 0) {
+               XSEGLOG2(&lc, E, "Invalid syntax: --insanity %s\n", insanity);
+               goto arg_fail;
+       }
+       SET_FLAG(INSANITY, prefs->flags, r);
+
+       /*****************************\
+        * Check I/O size parameters *
+       \*****************************/
+
+       //Block size (bs): Defaults to 4K.
+       //It must be a number followed by one of these characters:
+       //                                              [k|K|m|M|g|G]
+       //If not, it will be considered as size in bytes.
+       //Must be integer multiple of segment's page size (typically 4k).
+       if (!block_size[0])
+               strcpy(block_size,"4k");
+
+       prefs->bs = str2num(block_size);
+       if (!prefs->bs) {
+               XSEGLOG2(&lc, E, "Invalid syntax: -bs %s\n", block_size);
+               goto arg_fail;
+       } else if (prefs->bs % xseg_page_size) {
+               XSEGLOG2(&lc, E, "Misaligned block size: %s\n", block_size);
+               goto arg_fail;
+       }
+
+       //Total objects (to) or total I/O size (ts).
+       //Must have the same format as "block size"
+       //They are mutually exclusive
+       if (total_objects[0] && total_size[0]) {
+               XSEGLOG2(&lc, E, "Total objects and total size are mutually exclusive\n");
+               goto arg_fail;
+       } else if (total_objects[0]) {
+               prefs->to = str2num(total_objects);
+               if (!prefs->to) {
+                       XSEGLOG2(&lc, E, "Invalid syntax: -to %s\n", total_objects);
+                       goto arg_fail;
+               }
+               //In this case, the maximum number of requests is the total number of
+               //objects we will handle
+               prefs->status->max = prefs->to;
+       } else if (total_size[0]) {
+               if (prefs->op != X_READ && prefs->op != X_WRITE) {
+                       XSEGLOG2(&lc, E,
+                                       "Total objects must be supplied (required by -op %s)\n", op);
+                       goto arg_fail;
+               }
+               prefs->ts = str2num(total_size);
+               if (!prefs->ts) {
+                       XSEGLOG2(&lc, E, "Invalid syntax: -ts %s\n", total_size);
+                       goto arg_fail;
+               } else if (prefs->ts % prefs->bs) {
+                       XSEGLOG2(&lc, E, "Misaligned total I/O size: %s\n", total_size);
+                       goto arg_fail;
+               }
+               //In this case, the maximum number of requests is the number of blocks
+               //we need to cover the total I/O size
+               prefs->status->max = prefs->ts / prefs->bs;
+       } else {
+               XSEGLOG2(&lc, E, "Total objects or total size must be supplied\n");
+               goto arg_fail;
+       }
+
+       //Object size (os): Defaults to 4M.
+       //Must have the same format as "block size"
+       //Must be integer multiple of "block size"
+       if (!object_size[0])
+               strcpy(object_size,"4M");
+
+       prefs->os = str2num(object_size);
+       if (!prefs->os) {
+               XSEGLOG2(&lc, E, "Invalid syntax: -os %s\n", object_size);
+               goto arg_fail;
+       } else if (prefs->os % prefs->bs) {
+               XSEGLOG2(&lc, E, "Misaligned object size: %s\n", object_size);
+               goto arg_fail;
+       }
+
+
+       /*************************\
+        * Check port parameters *
+       \*************************/
+
+       if (dst_port < 0){
+               XSEGLOG2(&lc, E, "Target port must be supplied\n");
+               goto arg_fail;
+       }
+
+       prefs->src_port = peer->portno_start; //TODO: allow user to change this
+       prefs->dst_port = (xport) dst_port;
+
+       /*********************************\
+        * Create timers for all metrics *
+       \*********************************/
+
+       if (init_timer(&prefs->total_tm, INSANITY_SANE))
+               goto tm_fail;
+       if (init_timer(&prefs->sub_tm, INSANITY_MANIC))
+               goto tm_fail;
+       if (init_timer(&prefs->get_tm, INSANITY_PARANOID))
+               goto tm_fail;
+       if (init_timer(&prefs->rec_tm, INSANITY_ECCENTRIC))
+               goto tm_fail;
+
+       /*************************************\
+        * Initialize the LFSR and global_id *
+       \*************************************/
+reseed:
+       //We proceed to initialise the global_id, and seed variables.
+       if (seed == -1) {
+               clock_gettime(CLOCK_BENCH, &timer_seed);
+               seed = timer_seed.tv_nsec;
+       } else {
+               set_by_hand = 1;
+       }
+       create_id(seed);
+
+       if (GET_FLAG(PATTERN, prefs->flags) == PATTERN_RAND) {
+               prefs->lfsr = malloc(sizeof(struct bench_lfsr));
+               if (!prefs->lfsr) {
+                       perror("malloc");
+                       goto lfsr_fail;
+               }
+
+               r = lfsr_init(prefs->lfsr, prefs->status->max, seed, seed & 0xF);
+               if (r && set_by_hand) {
+                       XSEGLOG2(&lc, E, "LFSR could not be initialized.\n");
+                       goto lfsr_fail;
+               } else if (r) {
+                       seed = -1;
+                       goto reseed;
+               }
+       }
+
+       /*********************************\
+        * Miscellaneous initializations *
+       \*********************************/
+
+       /* The request cap must be enforced only after the LFSR is initialized */
+       if (request_cap[0]) {
+               rc = str2num(request_cap);
+               if (!rc) {
+                       XSEGLOG2(&lc, E, "Invalid syntax: -rc %s\n", request_cap);
+                       goto arg_fail;
+               } else if (rc > prefs->status->max) {
+                       XSEGLOG2(&lc, E, "Request cap exceeds current request total.\n");
+                       goto arg_fail;
+               }
+               prefs->status->max = rc;
+       }
+
+       /* Benchmarking progress printing is on by default */
+       if (!progress[0])
+               strcpy(progress, "yes");
+       r = read_progress(progress);
+       if (r < 0) {
+               XSEGLOG2(&lc, E, "Invalid syntax: --progress %s\n", progress);
+               goto arg_fail;
+       }
+       SET_FLAG(PROGRESS, prefs->flags, r);
+
+       prefs->peer = peer;
+       peer->peerd_loop = bench_peerd_loop;
+       peer->priv = (void *) prefs;
+       XSEGLOG2(&lc, I, "Global ID is %s\n", global_id);
+       return 0;
+
+arg_fail:
+       custom_peer_usage();
+lfsr_fail:
+       free(prefs->lfsr);
+tm_fail:
+       free(prefs->total_tm);
+       free(prefs->sub_tm);
+       free(prefs->get_tm);
+       free(prefs->rec_tm);
+       free(prefs);
+       return -1;
+}
+
+
+static int send_request(struct peerd *peer, struct bench *prefs)
+{
+       struct xseg_request *req;
+       struct xseg *xseg = peer->xseg;
+       struct peer_req *pr;
+       xport srcport = prefs->src_port;
+       xport dstport = prefs->dst_port;
+       xport p;
+
+       int r;
+       uint64_t new;
+       uint64_t size = prefs->bs;
+
+       //srcport and dstport must already be provided by the user.
+       //returns struct xseg_request with basic initializations
+       XSEGLOG2(&lc, D, "Get new request\n");
+       timer_start(prefs, prefs->get_tm);
+       req = xseg_get_request(xseg, srcport, dstport, X_ALLOC);
+       if (!req) {
+               XSEGLOG2(&lc, W, "Cannot get request\n");
+               return -1;
+       }
+       timer_stop(prefs, prefs->get_tm, NULL);
+
+       //Allocate enough space for the data and the target's name
+       XSEGLOG2(&lc, D, "Prepare new request\n");
+       r = xseg_prep_request(xseg, req, TARGETLEN, size);
+       if (r < 0) {
+               XSEGLOG2(&lc, W, "Cannot prepare request! (%lu, %llu)\n",
+                               TARGETLEN, (unsigned long long)size);
+               goto put_xseg_request;
+       }
+
+       //Determine what the next target/chunk will be, based on I/O pattern
+       new = determine_next(prefs);
+       req->op = prefs->op;
+       XSEGLOG2(&lc, I, "Our new request is %lu\n", new);
+       //Create a target of this format: "bench-<global_id>-<obj_no>"
+       create_target(prefs, req, new);
+
+       if (prefs->op == X_WRITE || prefs->op == X_READ) {
+               req->size = size;
+               //Calculate the chunk's offset inside the object
+               req->offset = calculate_offset(prefs, new);
+               XSEGLOG2(&lc, D, "Offset of request %lu is %lu\n", new, req->offset);
+
+               if (prefs->op == X_WRITE)
+                       create_chunk(prefs, req, new);
+       }
+
+
+       //Measure this?
+       XSEGLOG2(&lc, D, "Allocate peer request\n");
+       pr = alloc_peer_req(peer);
+       if (!pr) {
+               XSEGLOG2(&lc, W, "Cannot allocate peer request (%ld remaining)\n",
+                               peer->nr_ops - xq_count(&peer->free_reqs));
+               goto put_xseg_request;
+       }
+       pr->peer = peer;
+       pr->portno = srcport;
+       pr->req = req;
+       pr->priv = malloc(sizeof(struct timespec));
+       if (!pr->priv) {
+               perror("malloc");
+               goto put_peer_request;
+       }
+
+       //XSEGLOG2(&lc, D, "Set request data\n");
+       r = xseg_set_req_data(xseg, req, pr);
+       if (r < 0) {
+               XSEGLOG2(&lc, W, "Cannot set request data\n");
+               goto put_peer_request;
+       }
+
+       /*
+        * Start measuring receive time.
+        * When we receive a request, we need to have its submission time to
+        * measure elapsed time. Thus, we memcpy its submission time to pr->priv.
+        * QUESTION: Is this the fastest way?
+        */
+       timer_start(prefs, prefs->rec_tm);
+       if (prefs->rec_tm->insanity <= GET_FLAG(INSANITY, prefs->flags))
+               memcpy(pr->priv, &prefs->rec_tm->start_time, sizeof(struct timespec));
+
+       //Submit the request from the source port to the target port
+       XSEGLOG2(&lc, D, "Submit request %lu\n", new);
+       timer_start(prefs, prefs->sub_tm);
+       p = xseg_submit(xseg, req, srcport, X_ALLOC);
+       if (p == NoPort) {
+               XSEGLOG2(&lc, W, "Cannot submit request\n");
+               goto put_peer_request;
+       }
+       prefs->status->submitted++;
+       timer_stop(prefs, prefs->sub_tm, NULL);
+
+       //Send SIGIO to the process that has bound this port to inform that
+       //IO is possible
+       r = xseg_signal(xseg, p);
+       //if (r < 0)
+       //      XSEGLOG2(&lc, W, "Cannot signal destination peer (reason %d)\n", r);
+
+       return 0;
+
+put_peer_request:
+       free(pr->priv);
+       free_peer_req(peer, pr);
+put_xseg_request:
+       if (xseg_put_request(xseg, req, srcport))
+               XSEGLOG2(&lc, W, "Cannot put request\n");
+       return -1;
+}
+
+/*
+ * This function substitutes the default generic_peerd_loop of peer.c.
+ * It's plugged to struct peerd at custom peer's initialisation
+ */
+int bench_peerd_loop(void *arg)
+{
+#ifdef MT
+       struct thread *t = (struct thread *) arg;
+       struct peerd *peer = t->peer;
+       char *id = t->arg;
+#else
+       struct peerd *peer = (struct peerd *) arg;
+       char id[4] = {'P','e','e','r'};
+#endif
+       struct xseg *xseg = peer->xseg;
+       struct bench *prefs = peer->priv;
+       xport portno_start = peer->portno_start;
+       xport portno_end = peer->portno_end;
+       pid_t pid = syscall(SYS_gettid);
+       uint64_t threshold=1000/(1 + portno_end - portno_start);
+       uint64_t cached_prog_quantum = 0;
+       uint64_t prog_quantum = 0;
+       int r;
+       uint64_t loops;
+
+       if (GET_FLAG(PROGRESS, prefs->flags) == PROGRESS_YES) {
+               prog_quantum = calculate_prog_quantum(prefs);
+               cached_prog_quantum = prog_quantum;
+               print_stats(prefs);
+       }
+
+       XSEGLOG2(&lc, I, "%s has tid %u.\n",id, pid);
+       xseg_init_local_signal(xseg, peer->portno_start);
+
+       timer_start(prefs, prefs->total_tm);
+send_request:
+       while (!(isTerminate() && all_peer_reqs_free(peer))) {
+               while (CAN_SEND_REQUEST(prefs)) {
+                       xseg_cancel_wait(xseg, peer->portno_start);
+                       XSEGLOG2(&lc, D, "...because %lu < %lu && %lu < %lu\n",
+                                       prefs->status->submitted - prefs->status->received,
+                                       prefs->iodepth, prefs->status->received,
+                                       prefs->status->max);
+                       XSEGLOG2(&lc, D, "Start sending new request\n");
+                       r = send_request(peer, prefs);
+                       if (r < 0)
+                               break;
+               }
+               //Heart of peerd_loop. This loop is common for everyone.
+               for (loops = threshold; loops > 0; loops--) {
+                       if (loops == 1)
+                               xseg_prepare_wait(xseg, peer->portno_start);
+
+                       if (UNLIKELY(CAN_PRINT_PROGRESS(prefs, prog_quantum))) {
+                               prog_quantum += cached_prog_quantum;
+                               print_progress(prefs);
+                       }
+
+                       if (check_ports(peer)) {
+                               //If an old request has just been acked, the most sensible
+                               //thing to do is to immediately send a new one
+                               if (prefs->status->received < prefs->status->max)
+                                       goto send_request;
+                               else
+                                       return 0;
+                       }
+               }
+               //struct xseg_port *port = xseg_get_port(xseg, portno_start);
+               //struct xq *q;
+               //q = XPTR_TAKE(port->request_queue, xseg->segment);
+               //XSEGLOG2(&lc, I, "%s goes to sleep with %u requests pending\n",
+               //              id, xq_count(q));
+               XSEGLOG2(&lc, I, "%s goes to sleep\n", id);
+               xseg_wait_signal(xseg, 10000000UL);
+               xseg_cancel_wait(xseg, peer->portno_start);
+               XSEGLOG2(&lc, I, "%s woke up\n", id);
+       }
+
+       XSEGLOG2(&lc, I, "peer->free_reqs = %d, peer->nr_ops = %d\n",
+                       xq_count(&peer->free_reqs), peer->nr_ops);
+       return 0;
+}
+
+void custom_peer_finalize(struct peerd *peer)
+{
+       struct bench *prefs = peer->priv;
+       //TODO: Measure mean time, standard variation
+
+       if (!prefs->total_tm->completed)
+               timer_stop(prefs, prefs->total_tm, NULL);
+
+       if (GET_FLAG(PROGRESS, prefs->flags) == PROGRESS_YES)
+               print_progress(prefs);
+       else
+               print_stats(prefs);
+
+       print_remaining(prefs);
+       print_res(prefs, prefs->total_tm, "Total Requests");
+       return;
+}
+
+/*
+ * handle_received: +1 to our received requests.
+ * Do some sanity checks and then check if request is failed.
+ * If not try to verify the request if asked.
+ */
+static void handle_received(struct peerd *peer, struct peer_req *pr)
+{
+       //FIXME: handle null pointer
+       struct bench *prefs = peer->priv;
+       struct timer *rec = prefs->rec_tm;
+
+       prefs->status->received++;
+       if (!pr->req) {
+               //This is a serious error, so we must stop
+               XSEGLOG2(&lc, E, "Received peer request with no xseg request");
+               terminated++;
+               return;
+       }
+
+       if ((GET_FLAG(INSANITY, prefs->flags) < rec->insanity) && !pr->priv) {
+               XSEGLOG2(&lc, W, "Cannot find submission time of request");
+               return;
+       }
+
+       timer_stop(prefs, rec, pr->priv);
+
+       if (!(pr->req->state & XS_SERVED))
+               prefs->status->failed++;
+       else if (CAN_VERIFY(prefs) && read_chunk(prefs, pr->req))
+               prefs->status->corrupted++;
+
+       if (xseg_put_request(peer->xseg, pr->req, pr->portno))
+               XSEGLOG2(&lc, W, "Cannot put xseg request\n");
+
+       //QUESTION, can't we just keep the malloced memory for future use?
+       free(pr->priv);
+       free_peer_req(peer, pr);
+}
+
+int dispatch(struct peerd *peer, struct peer_req *pr, struct xseg_request *req,
+               enum dispatch_reason reason)
+{
+       switch (reason) {
+               case dispatch_accept:
+                       //This is wrong, benchmarking peer should not accept requests,
+                       //only receive them.
+                       XSEGLOG2(&lc, W, "Bench peer should not accept requests\n");
+                       complete(peer, pr);
+                       break;
+               case dispatch_receive:
+                       handle_received(peer, pr);
+                       break;
+               default:
+                       fail(peer, pr);
+       }
+       return 0;
+}