From b9cd13fedd8f077ecdd37857323eddddac285bc8 Mon Sep 17 00:00:00 2001
From: Florian Fischer <florian.fl.fischer@fau.de>
Date: Thu, 15 Aug 2019 19:27:59 +0200
Subject: [PATCH] implement alternative way to get memusage using wait4
run now forks the benchmark command instead of simply calling exec.
Ressource usage of the benchmark is retrieved with a call to wait4.
But the reported value ru_maxrss differs from values in /proc/<pid>/status.
---
src/Makefile | 4 +--
src/exec.c | 36 ----------------------
src/run.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 87 insertions(+), 38 deletions(-)
delete mode 100644 src/exec.c
create mode 100644 src/run.c
diff --git a/src/Makefile b/src/Makefile
index 8d6d110..00acfdc 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -15,7 +15,7 @@ MEMSIZE=$(shell echo $(MEMSIZE_KB)"* 1024" | bc)
.PHONY: all clean
-all: $(OBJDIR)/print_status_on_exit.so $(OBJDIR)/allocators/bumpptr_alloc.so $(OBJDIR)/exec
+all: $(OBJDIR)/print_status_on_exit.so $(OBJDIR)/allocators/bumpptr_alloc.so $(OBJDIR)/run
$(OBJDIR)/allocators/bumpptr_alloc.so: bumpptr_alloc.c Makefile | $(OBJDIR)/allocators
@echo "Compiling $@...";
@@ -26,7 +26,7 @@ $(OBJDIR)/print_status_on_exit.so: print_status_on_exit.c Makefile | $(OBJDIR)
@echo "Compiling $@...";
$(CC) $(LDFLAGS) -shared $(CFLAGS) -o $@ $<
-$(OBJDIR)/exec: exec.c Makefile | $(OBJDIR)
+$(OBJDIR)/run: run.c Makefile | $(OBJDIR)
@echo "Compiling $@...";
$(CC) $(LDFLAGS) $(CFLAGS) -o $@ $<
diff --git a/src/exec.c b/src/exec.c
deleted file mode 100644
index 4397992..0000000
--- a/src/exec.c
+++ /dev/null
@@ -1,36 +0,0 @@
-#define _GNU_SOURCE
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-int main(int argc, char* argv[]) {
- if (argc < 2) {
- printf("Usage: %s [-p LD_PRELOAD] [-l LD_LIBRARY_PATH] <cmd> [cmd args]\n", argv[0]);
- printf("\tset LD_PRELOAD to ld_preload and call execvp <cmd> [cmd args]\n");
- return 1;
- }
-
- int i = 1;
- for (; i < argc; i++) {
- // Overwrite LD_PRELOAD.
- if (strncmp(argv[i], "-p", 2) == 0) {
- setenv("LD_PRELOAD", argv[i+1], 1);
- i++;
- // Overwrite LD_LIBRARY_PATH.
- } else if (strncmp(argv[i], "-l", 2) == 0) {
- setenv("LD_LIBRARY_PATH", argv[i+1], 1);
- i++;
- } else {
- break;
- }
- }
-
-
- // Run cmd.
- execvp(argv[i], &argv[i]);
-
- fprintf(stderr, "executing %s failed\n", argv[i]);
-
- return 1;
-}
diff --git a/src/run.c b/src/run.c
new file mode 100644
index 0000000..3e89df6
--- /dev/null
+++ b/src/run.c
@@ -0,0 +1,85 @@
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/resource.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+static int child(int argc, char* argv[])
+{
+ char **newargv = malloc(sizeof(char*) * argc);
+ if (newargv == NULL)
+ {
+ perror("malloc");
+ return 1;
+ }
+
+ for (int i = 0; i < argc; i++)
+ {
+ newargv[i] = argv[i];
+ }
+ newargv[argc] = NULL;
+
+ execvp(newargv[0], newargv);
+
+ perror("execvp");
+ return 1;
+}
+
+int main(int argc, char* argv[]) {
+ if (argc < 2)
+ {
+ printf("Usage: %s [-p LD_PRELOAD] [-l LD_LIBRARY_PATH] <cmd> [cmd args]\n", argv[0]);
+ printf("\tset LD_PRELOAD to ld_preload and call execvp <cmd> [cmd args]\n");
+ return 1;
+ }
+
+ int status, child_val;
+ struct rusage r_usage;
+
+ int i = 1;
+ for (; i < argc; i++)
+ {
+ // Overwrite LD_PRELOAD.
+ if (strncmp(argv[i], "-p", 2) == 0)
+ {
+ setenv("LD_PRELOAD", argv[i+1], 1);
+ i++;
+ // Overwrite LD_LIBRARY_PATH.
+ } else if (strncmp(argv[i], "-l", 2) == 0)
+ {
+ setenv("LD_LIBRARY_PATH", argv[i+1], 1);
+ i++;
+ } else
+ {
+ break;
+ }
+ }
+
+ pid_t child_pid = fork();
+
+
+ if (child_pid == 0)
+ {
+ return child(argc - i, &argv[i]);
+ }
+ else if (child_pid > 0)
+ {
+ /* Collect child */
+ wait4(child_pid, &status, 0, &r_usage);
+ printf("child memory usage = %ld\n", r_usage.ru_maxrss);
+
+ /* Get child status value */
+ if (WIFEXITED(status))
+ {
+ child_val = WEXITSTATUS(status);
+ exit(child_val);
+ }
+ } else
+ {
+ perror("fork");
+ }
+
+ return 0;
+}
--
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