stress-mmap: add opt-in randomized madvise on pages

Currently mapped pages have randomized madvise set after each mmap operation, however, this can skew the bogo-op metrics for mmap'ings which the original stressor was intended to exercise. Make this optional opt-in with the new --mmap-madvise option. Signed-off-by: Colin Ian King <[email protected]>
ColinIanKing · Jan 18, 2024 · 2e265a6 · 2e265a6
1 parent aef94fd
commit 2e265a6
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Showing 4 changed files with 26 additions and 8 deletions.
diff --git a/core-opts.c b/core-opts.c
@@ -501,6 +501,7 @@ const struct option stress_long_options[] = {
 	{ "mmap-async",		0,	0,	OPT_mmap_async },
 	{ "mmap-bytes",		1,	0,	OPT_mmap_bytes },
 	{ "mmap-file",		0,	0,	OPT_mmap_file },
+	{ "mmap-madvise",	0,	0,	OPT_mmap_madvise },
 	{ "mmap-mprotect",	0,	0,	OPT_mmap_mprotect },
 	{ "mmap-odirect",	0,	0,	OPT_mmap_odirect },
 	{ "mmap-ops",		1,	0,	OPT_mmap_ops },

diff --git a/core-opts.h b/core-opts.h
@@ -757,16 +757,17 @@ typedef enum {
 	OPT_mlockmany_procs,
 
 	OPT_mmap,
-	OPT_mmap_ops,
+	OPT_mmap_async,
 	OPT_mmap_bytes,
 	OPT_mmap_file,
-	OPT_mmap_async,
-	OPT_mmap_mprotect,
-	OPT_mmap_osync,
-	OPT_mmap_odirect,
+	OPT_mmap_madvise,
 	OPT_mmap_mergeable,
 	OPT_mmap_mlock,
 	OPT_mmap_mmap2,
+	OPT_mmap_mprotect,
+	OPT_mmap_odirect,
+	OPT_mmap_ops,
+	OPT_mmap_osync,
 
 	OPT_mmapaddr,
 	OPT_mmapaddr_mlock,

diff --git a/stress-mmap.c b/stress-mmap.c
@@ -42,6 +42,7 @@ static const stress_help_t help[] = {
 	{ NULL,	"mmap-async",	 "using asynchronous msyncs for file based mmap" },
 	{ NULL,	"mmap-bytes N",	 "mmap and munmap N bytes for each stress iteration" },
 	{ NULL,	"mmap-file",	 "mmap onto a file using synchronous msyncs" },
+	{ NULL, "mmap-madvise",	 "enable random madvise on mmap'd region" },
 	{ NULL,	"mmap-mergeable","where possible, flag mmap'd pages as mergeable" },
 	{ NULL,	"mmap-mlock",	 "attempt to mlock mmap'd pages" },
 	{ NULL,	"mmap-mprotect", "enable mmap mprotect stressing" },
@@ -60,6 +61,7 @@ typedef struct {
 	size_t mmap_bytes;
 	bool mmap_async;
 	bool mmap_file;
+	bool mmap_madvise;
 	bool mmap_mergeable;
 	bool mmap_mlock;
 	bool mmap_mprotect;
@@ -275,6 +277,11 @@ static int stress_set_mmap_odirect(const char *opt)
 	return stress_set_setting_true("mmap-odirect", opt);
 }
 
+static int stress_set_mmap_madvise(const char *opt)
+{
+	return stress_set_setting_true("mmap-madvise", opt);
+}
+
 static int stress_set_mmap_mlock(const char *opt)
 {
 	return stress_set_setting_true("mmap-mlock", opt);
@@ -592,7 +599,8 @@ static int stress_mmap_child(stress_args_t *args, void *ctxt)
 			(void)shim_memset(buf, 0xff, sz);
 			(void)shim_msync((void *)buf, sz, ms_flags);
 		}
-		(void)stress_madvise_random(buf, sz);
+		if (context->mmap_madvise)
+			(void)stress_madvise_random(buf, sz);
 		if (context->mmap_mergeable)
 			(void)stress_madvise_mergeable(buf, sz);
 		(void)stress_mincore_touch_pages(buf, sz);
@@ -647,7 +655,8 @@ static int stress_mmap_child(stress_args_t *args, void *ctxt)
 							PROT_READ, MAP_FIXED, -1, 0));
 				}
 #endif
-				(void)stress_madvise_random(mappings[page], page_size);
+				if (context->mmap_madvise)
+					(void)stress_madvise_random(mappings[page], page_size);
 				stress_mmap_mprotect(args->name, mappings[page],
 					page_size, page_size, context->mmap_mprotect);
 			}
@@ -693,7 +702,8 @@ static int stress_mmap_child(stress_args_t *args, void *ctxt)
 					if (context->mmap_mlock)
 						(void)shim_mlock(mappings[page], page_size);
 					(void)stress_mincore_touch_pages(mappings[page], page_size);
-					(void)stress_madvise_random(mappings[page], page_size);
+					if (context->mmap_madvise)
+						(void)stress_madvise_random(mappings[page], page_size);
 					if (context->mmap_mergeable)
 						(void)stress_madvise_mergeable(mappings[page], page_size);
 					stress_mmap_mprotect(args->name, mappings[page],
@@ -896,6 +906,7 @@ static int stress_mmap(stress_args_t *args)
 	context.mmap_bytes = DEFAULT_MMAP_BYTES;
 	context.mmap_async = false;
 	context.mmap_file = false;
+	context.mmap_madvise = false;
 	context.mmap_mergeable = false;
 	context.mmap_mlock = false;
 	context.mmap_mprotect = false;
@@ -908,6 +919,7 @@ static int stress_mmap(stress_args_t *args)
 	(void)stress_get_setting("mmap-file", &context.mmap_file);
 	(void)stress_get_setting("mmap-osync", &mmap_osync);
 	(void)stress_get_setting("mmap-odirect", &mmap_odirect);
+	(void)stress_get_setting("mmap-madvise", &context.mmap_madvise);
 	(void)stress_get_setting("mmap-mergeable", &context.mmap_mergeable);
 	(void)stress_get_setting("mmap-mlock", &context.mmap_mlock);
 	(void)stress_get_setting("mmap-mmap2", &mmap_mmap2);
@@ -1044,6 +1056,7 @@ static const stress_opt_set_func_t opt_set_funcs[] = {
 	{ OPT_mmap_async,	stress_set_mmap_async },
 	{ OPT_mmap_bytes,	stress_set_mmap_bytes },
 	{ OPT_mmap_file,	stress_set_mmap_file },
+	{ OPT_mmap_madvise,	stress_set_mmap_madvise },
 	{ OPT_mmap_mergeable,	stress_set_mmap_mergeable },
 	{ OPT_mmap_mlock,	stress_set_mmap_mlock },
 	{ OPT_mmap_mmap2,	stress_set_mmap_mmap2 },

diff --git a/stress-ng.1 b/stress-ng.1
@@ -4211,6 +4211,9 @@ and GBytes using the suffix b, k, m or g.
 enable file based memory mapping and by default use synchronous msync'ing on
 each page.
 .TP
+.B \-\-mmap\-madvise
+enable randomized madvise(2) settings on pages.
+.TP
 .B \-\-mmap\-mergeable
 mark pages as mergeable via madvise(2) where possible.
 .TP