On 2024/10/12 6:49, Jaegeuk Kim via Linux-f2fs-devel wrote:
This adds a way to boost read performance by giving fadvise.
Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org>
---
tools/f2fs_io/f2fs_io.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
diff --git a/tools/f2fs_io/f2fs_io.c b/tools/f2fs_io/f2fs_io.c
index 8fbad3c8e563..5b67a92e0947 100644
--- a/tools/f2fs_io/f2fs_io.c
+++ b/tools/f2fs_io/f2fs_io.c
@@ -833,12 +833,15 @@ static void do_write_advice(int argc, char **argv, const
struct cmd_desc *cmd)
#define read_desc "read data from file"
#define read_help \
-"f2fs_io read [chunk_size in 4kb] [offset in chunk_size] [count] [IO]
[print_nbytes] [file_path]\n\n" \
+"f2fs_io read [chunk_size in 4kb] [offset in chunk_size] [count] [IO] [advice]
[print_nbytes] [file_path]\n\n" \
"Read data in file_path and print nbytes\n" \
"IO can be\n" \
" buffered : buffered IO\n" \
" dio : direct IO\n" \
" mmap : mmap IO\n" \
+"advice can be\n" \
+" 1 : set sequential|willneed\n" \
+" 0 : none\n" \
static void do_read(int argc, char **argv, const struct cmd_desc *cmd)
{
@@ -851,9 +854,9 @@ 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 fd;
+ int fd, advice;
- if (argc != 7) {
+ if (argc != 8) {
fputs("Excess arguments\n\n", stderr);
fputs(cmd->cmd_help, stderr);
exit(1);
@@ -876,13 +879,22 @@ static void do_read(int argc, char **argv, const struct
cmd_desc *cmd)
else if (strcmp(argv[4], "buffered"))
die("Wrong IO type");
- print_bytes = atoi(argv[5]);
+ print_bytes = atoi(argv[6]);
if (print_bytes > buf_size)
die("Print_nbytes should be less then chunk_size in kb");
print_buf = xmalloc(print_bytes);
- fd = xopen(argv[6], O_RDONLY | flags, 0);
+ fd = xopen(argv[7], O_RDONLY | flags, 0);
+
+ advice = atoi(argv[5]);
+ if (advice) {
+ if (posix_fadvise(fd, 0, 4096, POSIX_FADV_SEQUENTIAL) != 0)
+ die_errno("fadvise failed");
+ if (posix_fadvise(fd, 0, 4096, POSIX_FADV_WILLNEED) != 0)
+ die_errno("fadvise failed");
+ printf("fadvise SEQUENTIAL|WILLNEED to a file: %s\n", argv[7]);
+ }
total_time = get_current_us();
if (do_mmap) {
@@ -912,8 +924,9 @@ static void do_read(int argc, char **argv, const struct
cmd_desc *cmd)
read_cnt = count * buf_size;
memcpy(print_buf, data, print_bytes);
}
- printf("Read %"PRIu64" bytes total_time = %"PRIu64" us, print %u
bytes:\n",
- read_cnt, get_current_us() - total_time, 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,
+ ((long double)read_cnt / (get_current_us() - total_time) *
1000/1024 * 1000/1024 ), print_bytes);
((long double)read_cnt / (get_current_us() - total_time) / 1000 / 1000) ?
printf("%08"PRIx64" : ", offset);
for (i = 1; i <= print_bytes; i++) {
printf("%02x", print_buf[i - 1]);
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