From: Jens Axboe <axboe@suse.de>
Date: Fri, 18 Nov 2005 10:10:00 +0000 (+0100)
Subject: [PATCH] Add mem=mmap option to use anon mmap for buffer memory
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=891e70f85ee35826fee5cefd0c533f900635dc59;p=disktools.git

[PATCH] Add mem=mmap option to use anon mmap for buffer memory
---

diff --git a/README.fio b/README.fio
index ed9cae2..f789bce 100644
--- a/README.fio
+++ b/README.fio
@@ -47,7 +47,7 @@ The <jobs> format is as follows:
 	invalidate=x	Invalidate page cache for file prior to doing io
 	sync=x		Use sync writes if x and writing
 	mem=x		If x == malloc, use malloc for buffers. If x == shm,
-			use shm for buffers.
+			use shm for buffers. If x == mmap, use anon mmap.
 	exitall		When one thread quits, terminate the others
 	bwavgtime=x	Average bandwidth stats over x msec
 	create_serialize=x	If 'x', serialize file creation.
diff --git a/fio-ini.c b/fio-ini.c
index 55347ac..4a8f474 100644
--- a/fio-ini.c
+++ b/fio-ini.c
@@ -608,6 +608,11 @@ int parse_jobs_ini(char *file)
 				fgetpos(f, &off);
 				continue;
 			}
+			if (!check_str(p, "mem", "mmap")) {
+				td->mem_type = MEM_MMAP;
+				fgetpos(f, &off);
+				continue;
+			}
 			if (!check_strset(p, "sequential")) {
 				td->sequential = 1;
 				fgetpos(f, &off);
diff --git a/fio.c b/fio.c
index c46b5ac..976e0a6 100644
--- a/fio.c
+++ b/fio.c
@@ -1105,13 +1105,18 @@ static void cleanup_io_u(struct thread_data *td)
 
 		shmdt(td->orig_buffer);
 		shmctl(td->shm_id, IPC_RMID, &sbuf);
-	}
+	} else if (td->mem_type == MEM_MMAP)
+		munmap(td->orig_buffer, td->orig_buffer_size);
+	else
+		fprintf(stderr, "Bad memory type %d\n", td->mem_type);
+
+	td->orig_buffer = NULL;
 }
 
 static int init_io_u(struct thread_data *td)
 {
 	struct io_u *io_u;
-	int i, max_units, mem_size;
+	int i, max_units;
 	char *p;
 
 	if (!td->use_aio)
@@ -1119,12 +1124,12 @@ static int init_io_u(struct thread_data *td)
 	else
 		max_units = td->aio_depth;
 
-	mem_size = td->max_bs * max_units + MASK;
+	td->orig_buffer_size = td->max_bs * max_units + MASK;
 
 	if (td->mem_type == MEM_MALLOC)
-		td->orig_buffer = malloc(mem_size);
+		td->orig_buffer = malloc(td->orig_buffer_size);
 	else if (td->mem_type == MEM_SHM) {
-		td->shm_id = shmget(IPC_PRIVATE, mem_size, IPC_CREAT | 0600);
+		td->shm_id = shmget(IPC_PRIVATE, td->orig_buffer_size, IPC_CREAT | 0600);
 		if (td->shm_id < 0) {
 			td->error = errno;
 			perror("shmget");
@@ -1135,6 +1140,15 @@ static int init_io_u(struct thread_data *td)
 		if (td->orig_buffer == (void *) -1) {
 			td->error = errno;
 			perror("shmat");
+			td->orig_buffer = NULL;
+			return 1;
+		}
+	} else if (td->mem_type == MEM_MMAP) {
+		td->orig_buffer = mmap(NULL, td->orig_buffer_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
+		if (td->orig_buffer == MAP_FAILED) {
+			td->error = errno;
+			perror("mmap");
+			td->orig_buffer = NULL;
 			return 1;
 		}
 	}
diff --git a/fio.h b/fio.h
index 6dfdc47..b8d3967 100644
--- a/fio.h
+++ b/fio.h
@@ -64,6 +64,7 @@ struct thread_data {
 	void *mmap;
 	pid_t pid;
 	char *orig_buffer;
+	size_t orig_buffer_size;
 	volatile int terminate;
 	volatile int runstate;
 	volatile int old_runstate;
@@ -179,11 +180,18 @@ enum {
 	DDIR_WRITE,
 };
 
+/*
+ * What type of allocation to use for io buffers
+ */
 enum {
-	MEM_MALLOC,
-	MEM_SHM,
+	MEM_MALLOC,	/* ordinary malloc */
+	MEM_SHM,	/* use shared memory segments */
+	MEM_MMAP,	/* use anonynomous mmap */
 };
 
+/*
+ * The type of object we are working on
+ */
 enum {
 	FIO_TYPE_FILE = 1,
 	FIO_TYPE_BD,