engines/libpmem: cleanup a little code, comments and example

Signed-off-by: Łukasz Stolarczuk <lukasz.stolarczuk@intel.com>

diff --git a/engines/libpmem.c b/engines/libpmem.c
index 364e384de7e4071420eb13fe9b987f44ecd6bbff..3502911257e70e8d9afef63eb280e1999859f04a 100644 (file)
--- a/engines/libpmem.c
+++ b/engines/libpmem.c
@@ -18,7 +18,8 @@
 /*
  * libpmem engine
  *
- * IO engine that uses libpmem to write data (and memcpy to read)
+ * IO engine that uses libpmem (part of PMDK collection) to write data
+ *     and libc's memcpy to read. It requires PMDK >= 1.5.
  *
  * To use:
  *   ioengine=libpmem
@@ -43,25 +44,13 @@
  *     mkdir /mnt/pmem0
  *     mount -o dax /dev/pmem0 /mnt/pmem0
  *
- * See examples/libpmem.fio for more.
- *
- *
- * libpmem.so
- *   By default, the libpmem engine will let the system find the libpmem.so
- *   that it uses. You can use an alternative libpmem by setting the
- *   FIO_PMEM_LIB environment variable to the full path to the desired
- *   libpmem.so. This engine requires PMDK >= 1.5.
+ * See examples/libpmem.fio for complete usage example.
  */
 
 #include <stdio.h>
-#include <limits.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <errno.h>
-#include <sys/mman.h>
-#include <sys/stat.h>
-#include <sys/sysmacros.h>
-#include <libgen.h>
 #include <libpmem.h>
 
 #include "../fio.h"
@@ -77,8 +66,8 @@ static int fio_libpmem_init(struct thread_data *td)
 {
        struct thread_options *o = &td->o;
 
-       dprint(FD_IO,"o->rw_min_bs %llu \n o->fsync_blocks %u \n o->fdatasync_blocks %u \n",
-                       o->rw_min_bs,o->fsync_blocks,o->fdatasync_blocks);
+       dprint(FD_IO, "o->rw_min_bs %llu\n o->fsync_blocks %u\n o->fdatasync_blocks %u\n",
+                       o->rw_min_bs, o->fsync_blocks, o->fdatasync_blocks);
        dprint(FD_IO, "DEBUG fio_libpmem_init\n");
 
        if ((o->rw_min_bs & page_mask) &&
@@ -91,7 +80,8 @@ static int fio_libpmem_init(struct thread_data *td)
 }
 
 /*
- * This is the pmem_map_file execution function
+ * This is the pmem_map_file execution function, a helper to
+ * fio_libpmem_open_file function.
  */
 static int fio_libpmem_file(struct thread_data *td, struct fio_file *f,
                            size_t length, off_t off)
@@ -135,11 +125,11 @@ static int fio_libpmem_open_file(struct thread_data *td, struct fio_file *f)
 {
        struct fio_libpmem_data *fdd;
 
-       dprint(FD_IO,"DEBUG fio_libpmem_open_file\n");
-       dprint(FD_IO,"f->io_size=%ld \n",f->io_size);
-       dprint(FD_IO,"td->o.size=%lld \n",td->o.size);
-       dprint(FD_IO,"td->o.iodepth=%d\n",td->o.iodepth);
-       dprint(FD_IO,"td->o.iodepth_batch=%d \n",td->o.iodepth_batch);
+       dprint(FD_IO, "DEBUG fio_libpmem_open_file\n");
+       dprint(FD_IO, "f->io_size=%ld\n", f->io_size);
+       dprint(FD_IO, "td->o.size=%lld\n", td->o.size);
+       dprint(FD_IO, "td->o.iodepth=%d\n", td->o.iodepth);
+       dprint(FD_IO, "td->o.iodepth_batch=%d\n", td->o.iodepth_batch);
 
        if (fio_file_open(f))
                td_io_close_file(td, f);
@@ -160,8 +150,8 @@ static int fio_libpmem_prep(struct thread_data *td, struct io_u *io_u)
        struct fio_file *f = io_u->file;
        struct fio_libpmem_data *fdd = FILE_ENG_DATA(f);
 
-       dprint(FD_IO, "DEBUG fio_libpmem_prep\n" );
-       dprint(FD_IO," io_u->offset %llu : fdd->libpmem_off %ld : "
+       dprint(FD_IO, "DEBUG fio_libpmem_prep\n");
+       dprint(FD_IO, "io_u->offset %llu : fdd->libpmem_off %ld : "
                        "io_u->buflen %llu : fdd->libpmem_sz %ld\n",
                        io_u->offset, fdd->libpmem_off,
                        io_u->buflen, fdd->libpmem_sz);
@@ -185,8 +175,9 @@ static enum fio_q_status fio_libpmem_queue(struct thread_data *td,
        io_u->error = 0;
 
        dprint(FD_IO, "DEBUG fio_libpmem_queue\n");
-       dprint(FD_IO,"td->o.odirect %d td->o.sync_io %d \n",td->o.odirect, td->o.sync_io);
-       /* map both O_SYNC / DSYNC to not using NODRAIN */
+       dprint(FD_IO, "td->o.odirect %d td->o.sync_io %d\n",
+                       td->o.odirect, td->o.sync_io);
+       /* map both O_SYNC / DSYNC to not use NODRAIN */
        flags = td->o.sync_io ? 0 : PMEM_F_MEM_NODRAIN;
        flags |= td->o.odirect ? PMEM_F_MEM_NONTEMPORAL : PMEM_F_MEM_TEMPORAL;
 
@@ -196,7 +187,7 @@ static enum fio_q_status fio_libpmem_queue(struct thread_data *td,
                break;
        case DDIR_WRITE:
                dprint(FD_IO, "DEBUG mmap_data=%p, xfer_buf=%p\n",
-                               io_u->mmap_data, io_u->xfer_buf );
+                               io_u->mmap_data, io_u->xfer_buf);
                pmem_memcpy(io_u->mmap_data,
                                        io_u->xfer_buf,
                                        io_u->xfer_buflen,
@@ -220,8 +211,8 @@ static int fio_libpmem_close_file(struct thread_data *td, struct fio_file *f)
        struct fio_libpmem_data *fdd = FILE_ENG_DATA(f);
        int ret = 0;
 
-       dprint(FD_IO,"DEBUG fio_libpmem_close_file\n");
-       dprint(FD_IO,"td->o.odirect %d \n",td->o.odirect);
+       dprint(FD_IO, "DEBUG fio_libpmem_close_file\n");
+       dprint(FD_IO, "td->o.odirect %d\n", td->o.odirect);
 
        if (!td->o.odirect) {
                dprint(FD_IO,"pmem_drain\n");

diff --git a/examples/libpmem.fio b/examples/libpmem.fio
index 0ff681f071981e37d6e5d79438c6d4b3b6fa49f0..3b854a32bff724d2f82ebc1dacb399e5fb2046c9 100644 (file)
--- a/examples/libpmem.fio
+++ b/examples/libpmem.fio
@@ -1,6 +1,6 @@
 [global]
 bs=4k
-size=8g
+size=10g
 ioengine=libpmem
 norandommap
 time_based
@@ -17,16 +17,6 @@ thread
 numjobs=1
 runtime=300
 
-#
-# In case of 'scramble_buffers=1', the source buffer
-# is rewritten with a random value every write operations.
-#
-# But when 'scramble_buffers=0' is set, the source buffer isn't
-# rewritten. So it will be likely that the source buffer is in CPU
-# cache and it seems to be high performance.
-#
-scramble_buffers=0
-
 #
 # depends on direct option, flags are set for pmem_memcpy() call:
 # direct=1 - PMEM_F_MEM_NONTEMPORAL,
@@ -39,9 +29,19 @@ direct=1
 #
 sync=1
 
+#
+# In case of 'scramble_buffers=1', the source buffer
+# is rewritten with a random value every write operation.
+#
+# But when 'scramble_buffers=0' is set, the source buffer isn't
+# rewritten. So it will be likely that the source buffer is in CPU
+# cache and it seems to be high write performance.
+#
+scramble_buffers=1
 
 #
-# Setting for fio process's CPU Node and Memory Node
+# Setting for fio process's CPU Node and Memory Node.
+# Set proper node below or use `numactl` command along with FIO.
 #
 numa_cpu_nodes=0
 numa_mem_policy=bind:0
@@ -53,21 +53,22 @@ cpus_allowed_policy=split
 
 #
 # The libpmem engine does IO to files in a DAX-mounted filesystem.
-# The filesystem should be created on an NVDIMM (e.g /dev/pmem0)
+# The filesystem should be created on a Non-Volatile DIMM (e.g /dev/pmem0)
 # and then mounted with the '-o dax' option.  Note that the engine
 # accesses the underlying NVDIMM directly, bypassing the kernel block
 # layer, so the usual filesystem/disk performance monitoring tools such
 # as iostat will not provide useful data.
 #
-directory=/mnt/pmem0
+#filename=/mnt/pmem/somefile
+directory=/mnt/pmem
 
 [libpmem-seqwrite]
 rw=write
 stonewall
 
-#[libpmem-seqread]
-#rw=read
-#stonewall
+[libpmem-seqread]
+rw=read
+stonewall
 
 #[libpmem-randwrite]
 #rw=randwrite