From 41f45fa176661fb26069f1d492f48a07e0bb88eb Mon Sep 17 00:00:00 2001
From: "Peter W. Draper" <p.w.draper@durham.ac.uk>
Date: Mon, 2 Mar 2020 12:14:09 +0000
Subject: [PATCH] Fix a memory allocation bug (*nlogs) and stop allocating all
the buffer memory upfront
Not allocating upfront will reduce the overall memory footprint, but may slow down the send and recv loops
---
swiftmpistepsim.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/swiftmpistepsim.c b/swiftmpistepsim.c
index 394dea0..8a4a257 100644
--- a/swiftmpistepsim.c
+++ b/swiftmpistepsim.c
@@ -127,6 +127,7 @@ static void *inject_thread(void *arg) {
/* Differences to SWIFT: MPI_BYTE not the MPI_Type. */
int err = 0;
if (log->type == task_type_send) {
+ log->data = calloc(log->size, 1);
err = MPI_Isend(log->data, log->size, MPI_BYTE, log->otherrank, log->tag,
subtypeMPI_comms[log->subtype], &log->req);
@@ -136,6 +137,7 @@ static void *inject_thread(void *arg) {
atomic_inc(&todo_send);
} else {
+ log->data = calloc(log->size, 1);
err = MPI_Irecv(log->data, log->size, MPI_BYTE, log->otherrank, log->tag,
subtypeMPI_comms[log->subtype], &log->req);
@@ -325,7 +327,7 @@ static void pick_logs(void) {
nlogs, sizeof(struct mpiuse_log_entry *));
nr_reqs = 0;
sends_queue = (struct mpiuse_log_entry **)calloc(
- nlogs, sizeof(struct mpiuse_log_entry *) * nlogs);
+ nlogs, sizeof(struct mpiuse_log_entry *));
nr_sends = 0;
recvs_queue = (struct mpiuse_log_entry **)calloc(
nlogs, sizeof(struct mpiuse_log_entry *));
@@ -336,10 +338,8 @@ static void pick_logs(void) {
if (log->rank == myrank && log->activation) {
if (log->type == task_type_send || log->type == task_type_recv) {
- /* Allocate space for data. */
- log->data = calloc(log->size, 1);
-
/* And keep this log. */
+ log->data = NULL;
reqs_queue[nr_reqs] = log;
nr_reqs++;
--
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