[f2fs-dev] [PATCH 1/3] f2fs_io: add mlock to measure the read speed

[Jaegeuk Kim via Linux-f2fs-devel]

Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org>
---
 tools/f2fs_io/f2fs_io.c | 32 ++++++++++++++++++++++++++------
 1 file changed, 26 insertions(+), 6 deletions(-)

diff --git a/tools/f2fs_io/f2fs_io.c b/tools/f2fs_io/f2fs_io.c
index b9bf9bc5f797..2d64eda81706 100644
--- a/tools/f2fs_io/f2fs_io.c
+++ b/tools/f2fs_io/f2fs_io.c
@@ -931,6 +931,7 @@ static void do_write_advice(int argc, char **argv, const 
struct cmd_desc *cmd)
 "  buffered : buffered IO\n"                           \
 "  dio      : direct IO\n"                             \
 "  mmap     : mmap IO\n"                               \
+"  mlock    : mmap + mlock\n"                          \
 "advice can be\n"                                      \
 " 1 : set sequential|willneed\n"                       \
 " 0 : none\n"                                          \
@@ -946,6 +947,7 @@ static void do_read(int argc, char **argv, const struct 
cmd_desc *cmd)
        u64 total_time = 0;
        int flags = 0;
        int do_mmap = 0;
+       int do_mlock = 0;
        int fd, advice;
 
        if (argc != 8) {
@@ -968,6 +970,8 @@ static void do_read(int argc, char **argv, const struct 
cmd_desc *cmd)
                flags |= O_DIRECT;
        else if (!strcmp(argv[4], "mmap"))
                do_mmap = 1;
+       else if (!strcmp(argv[4], "mlock"))
+               do_mlock = 1;
        else if (strcmp(argv[4], "buffered"))
                die("Wrong IO type");
 
@@ -993,11 +997,24 @@ static void do_read(int argc, char **argv, const struct 
cmd_desc *cmd)
        total_time = get_current_us();
        if (do_mmap) {
                data = mmap(NULL, count * buf_size, PROT_READ,
-                                               MAP_SHARED | MAP_POPULATE, fd, 
offset);
+                               MAP_SHARED | MAP_POPULATE, fd, offset);
                if (data == MAP_FAILED)
                        die("Mmap failed");
-       }
-       if (!do_mmap) {
+
+               read_cnt = count * buf_size;
+               memcpy(print_buf, data, print_bytes);
+       } else if (do_mlock) {
+               data = mmap(NULL, count * buf_size, PROT_READ,
+                               MAP_SHARED, fd, offset);
+               if (data == MAP_FAILED)
+                       die("Mmap failed");
+               if (posix_fadvise(fd, offset, count * buf_size,
+                                       POSIX_FADV_WILLNEED) != 0)
+                       die_errno("fadvise failed");
+               if (mlock(data, count * buf_size))
+                       die_errno("mlock failed");
+               read_cnt = count * buf_size;
+       } else {
                for (i = 0; i < count; i++) {
                        ret = pread(fd, buf, buf_size, offset + buf_size * i);
                        if (ret != buf_size) {
@@ -1014,9 +1031,6 @@ static void do_read(int argc, char **argv, const struct 
cmd_desc *cmd)
                        if (i == 0)
                                memcpy(print_buf, buf, print_bytes);
                }
-       } else {
-               read_cnt = count * buf_size;
-               memcpy(print_buf, data, print_bytes);
        }
        printf("Read %"PRIu64" bytes total_time = %"PRIu64" us, BW = %.Lf MB/s 
print %u bytes:\n",
                read_cnt, get_current_us() - total_time,
@@ -1029,6 +1043,12 @@ static void do_read(int argc, char **argv, const struct 
cmd_desc *cmd)
                else if (i % 2 == 0)
                        printf(" ");
        }
+       if (do_mmap) {
+               munmap(data, count * buf_size);
+       } else if (do_mlock) {
+               munlock(data, count * buf_size);
+               munmap(data, count * buf_size);
+       }
        printf("\n");
        exit(0);
 }
-- 
2.51.0.470.ga7dc726c21-goog



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