On Thu, Feb 14 2013, Nikolaus Jeremic wrote:
> Hi,
>
> I've tried to replay I/Os from a textual iolog file to a couple of files
> using fio 2.0.13 on Linux. However, all I/Os were performed to the last
> opened file, which is '/mnt/ssd5/rand-write.1.0_1_2' in this example . My
> jobfile and iolog files contain the following:
>
> ############### job file #########
> [global]
> name=replay_filetraces
> description=Replay file traces
> ioengine=libaio
> iodepth=6
> direct=1
> continue_on_error=1
>
> [replay]
> numjobs=1
> read_iolog=file_io_patterns
> unlink=0
> ############## EOF #########
>
>
> ############## iolog file #########
> fio version 2 iolog
> /mnt/ssd0/rand-write.1.0_0_0 add
> /mnt/ssd1/rand-write.1.0_0_1 add
> /mnt/ssd2/rand-write.1.0_0_2 add
> /mnt/ssd3/rand-write.1.0_1_0 add
> /mnt/ssd4/rand-write.1.0_1_1 add
> /mnt/ssd5/rand-write.1.0_1_2 add
> /mnt/ssd0/rand-write.1.0_0_0 open
> /mnt/ssd1/rand-write.1.0_0_1 open
> /mnt/ssd2/rand-write.1.0_0_2 open
> /mnt/ssd3/rand-write.1.0_1_0 open
> /mnt/ssd4/rand-write.1.0_1_1 open
> /mnt/ssd5/rand-write.1.0_1_2 open
> /mnt/ssd0/rand-write.1.0_0_0 write 0 65536
> /mnt/ssd1/rand-write.1.0_0_1 write 0 65536
> /mnt/ssd2/rand-write.1.0_0_2 write 0 65536
> /mnt/ssd3/rand-write.1.0_1_0 write 0 65536
> /mnt/ssd4/rand-write.1.0_1_1 write 0 65536
> /mnt/ssd5/rand-write.1.0_1_2 write 0 65536
> /mnt/ssd0/rand-write.1.0_0_0 write 65536 65536
> /mnt/ssd1/rand-write.1.0_0_1 write 65536 65536
> /mnt/ssd2/rand-write.1.0_0_2 write 65536 65536
> /mnt/ssd3/rand-write.1.0_1_0 write 65536 65536
> /mnt/ssd4/rand-write.1.0_1_1 write 65536 65536
> /mnt/ssd5/rand-write.1.0_1_2 write 65536 65536
> /mnt/ssd0/rand-write.1.0_0_0 close
> /mnt/ssd1/rand-write.1.0_0_1 close
> /mnt/ssd2/rand-write.1.0_0_2 close
> /mnt/ssd3/rand-write.1.0_1_0 close
> /mnt/ssd4/rand-write.1.0_1_1 close
> /mnt/ssd5/rand-write.1.0_1_2 close
> ############## EOF #########
>
> I've turned on debugging and added some extra printf in read_iolog2() within
> iolog.c.
>
> ############## begin of debug excerpt ########
> file 24594 add file /mnt/ssd0/rand-write.1.0_0_0
> file 24594 resize file array to 2 files
> file 24594 file 0x7fbe03f53090 "/mnt/ssd0/rand-write.1.0_0_0" added at 0
> file 24594 add file /mnt/ssd1/rand-write.1.0_0_1
> file 24594 file 0x7fbe03f53230 "/mnt/ssd1/rand-write.1.0_0_1" added at 1
> file 24594 add file /mnt/ssd2/rand-write.1.0_0_2
> file 24594 resize file array to 4 files
> file 24594 file 0x7fbe03f533d0 "/mnt/ssd2/rand-write.1.0_0_2" added at 2
> file 24594 add file /mnt/ssd3/rand-write.1.0_1_0
> file 24594 file 0x7fbe03f53570 "/mnt/ssd3/rand-write.1.0_1_0" added at 3
> file 24594 add file /mnt/ssd4/rand-write.1.0_1_1
> file 24594 resize file array to 6 files
> file 24594 file 0x7fbe03f53710 "/mnt/ssd4/rand-write.1.0_1_1" added at 4
> file 24594 add file /mnt/ssd5/rand-write.1.0_1_2
> file 24594 file 0x7fbe03f538b0 "/mnt/ssd5/rand-write.1.0_1_2" added at 5
> io 24594 read_iolog2: Making note of file. offset=7310584035475809390
> bytes=811544671 fileno=0 file_action=1 fname=/mnt/ssd0/rand-write.1.0_0_0
> act=open
> io 24594 read_iolog2: Making note of file. offset=7310584035475809390
> bytes=811544671 fileno=1 file_action=1 fname=/mnt/ssd1/rand-write.1.0_0_1
> act=open
> io 24594 read_iolog2: Making note of file. offset=7310584035475809390
> bytes=811544671 fileno=2 file_action=1 fname=/mnt/ssd2/rand-write.1.0_0_2
> act=open
> io 24594 read_iolog2: Making note of file. offset=7310584035475809390
> bytes=811544671 fileno=3 file_action=1 fname=/mnt/ssd3/rand-write.1.0_1_0
> act=open
> io 24594 read_iolog2: Making note of file. offset=7310584035475809390
> bytes=811544671 fileno=4 file_action=1 fname=/mnt/ssd4/rand-write.1.0_1_1
> act=open
> io 24594 read_iolog2: Making note of file. offset=7310584035475809390
> bytes=811544671 fileno=5 file_action=1 fname=/mnt/ssd5/rand-write.1.0_1_2
> act=open
> io 24594 read_iolog2: Making note of file. offset=0 bytes=65536
> fileno=5 file_action=1 fname=/mnt/ssd0/rand-write.1.0_0_0 act=write
> io 24594 read_iolog2: Making note of file. offset=0 bytes=65536
> fileno=5 file_action=1 fname=/mnt/ssd1/rand-write.1.0_0_1 act=write
> io 24594 read_iolog2: Making note of file. offset=0 bytes=65536
> fileno=5 file_action=1 fname=/mnt/ssd2/rand-write.1.0_0_2 act=write
> io 24594 read_iolog2: Making note of file. offset=0 bytes=65536
> fileno=5 file_action=1 fname=/mnt/ssd3/rand-write.1.0_1_0 act=write
> io 24594 read_iolog2: Making note of file. offset=0 bytes=65536
> fileno=5 file_action=1 fname=/mnt/ssd4/rand-write.1.0_1_1 act=write
> io 24594 read_iolog2: Making note of file. offset=0 bytes=65536
> fileno=5 file_action=1 fname=/mnt/ssd5/rand-write.1.0_1_2 act=write
> io 24594 read_iolog2: Making note of file. offset=65536 bytes=65536
> fileno=5 file_action=1 fname=/mnt/ssd0/rand-write.1.0_0_0 act=write
> io 24594 read_iolog2: Making note of file. offset=65536 bytes=65536
> fileno=5 file_action=1 fname=/mnt/ssd1/rand-write.1.0_0_1 act=write
> io 24594 read_iolog2: Making note of file. offset=65536 bytes=65536
> fileno=5 file_action=1 fname=/mnt/ssd2/rand-write.1.0_0_2 act=write
> io 24594 read_iolog2: Making note of file. offset=65536 bytes=65536
> fileno=5 file_action=1 fname=/mnt/ssd3/rand-write.1.0_1_0 act=write
> io 24594 read_iolog2: Making note of file. offset=65536 bytes=65536
> fileno=5 file_action=1 fname=/mnt/ssd4/rand-write.1.0_1_1 act=write
> io 24594 read_iolog2: Making note of file. offset=65536 bytes=65536
> fileno=5 file_action=1 fname=/mnt/ssd5/rand-write.1.0_1_2 act=write
> io 24594 read_iolog2: Making note of file. offset=65536 bytes=65536
> fileno=0 file_action=2 fname=/mnt/ssd0/rand-write.1.0_0_0 act=close
> io 24594 read_iolog2: Making note of file. offset=65536 bytes=65536
> fileno=1 file_action=2 fname=/mnt/ssd1/rand-write.1.0_0_1 act=close
> io 24594 read_iolog2: Making note of file. offset=65536 bytes=65536
> fileno=2 file_action=2 fname=/mnt/ssd2/rand-write.1.0_0_2 act=close
> io 24594 read_iolog2: Making note of file. offset=65536 bytes=65536
> fileno=3 file_action=2 fname=/mnt/ssd3/rand-write.1.0_1_0 act=close
> io 24594 read_iolog2: Making note of file. offset=65536 bytes=65536
> fileno=4 file_action=2 fname=/mnt/ssd4/rand-write.1.0_1_1 act=close
> io 24594 read_iolog2: Making note of file. offset=65536 bytes=65536
> fileno=5 file_action=2 fname=/mnt/ssd5/rand-write.1.0_1_2 act=close
> ############## end of debug excerpt ########
>
> Taking a look to the debugging output shows that on write action the
> 'fileno' variable is always set to 5 regardless of the file that should be
> written. However, for open and close we have a different fileno value for
> each file. Taking a look into the source code of read_iolog2() reveals why:
> In case of actions 'open' or 'close', 'fileno' is looked up through
> 'get_fileno(td, fname)', but for 'write', 'read' and the other 4 argument
> actions 'fileno' is not looked up. When I add a 'fileno = get_fileno(td,
> fname);' at the end of the '(r == 4)' branch, I/Os are replayed to the
> designated files.
>
> ########## excerpt from read_iolog2() within iolog.c ######
> if (r == 4) {
> /*
> * Check action first
> */
> if (!strcmp(act, "wait"))
> rw = DDIR_WAIT;
> else if (!strcmp(act, "read"))
> rw = DDIR_READ;
> else if (!strcmp(act, "write"))
> rw = DDIR_WRITE;
> else if (!strcmp(act, "sync"))
> rw = DDIR_SYNC;
> else if (!strcmp(act, "datasync"))
> rw = DDIR_DATASYNC;
> else if (!strcmp(act, "trim"))
> rw = DDIR_TRIM;
> else {
> log_err("fio: bad iolog file action: %s\n",
> act);
> continue;
> }
> } else if (r == 2) {
> rw = DDIR_INVAL;
> if (!strcmp(act, "add")) {
> td->o.nr_files++;
> fileno = add_file(td, fname);
> file_action = FIO_LOG_ADD_FILE;
> continue;
> } else if (!strcmp(act, "open")) {
> fileno = get_fileno(td, fname);
> file_action = FIO_LOG_OPEN_FILE;
> } else if (!strcmp(act, "close")) {
> fileno = get_fileno(td, fname);
> file_action = FIO_LOG_CLOSE_FILE;
> } else {
> log_err("fio: bad iolog file action: %s\n",
> act);
> continue;
> }
> } else {
> log_err("bad iolog2: %s", p);
> continue;
> }
> ########## end ######
Thanks for the detailed and thorough analysis. Care to resend this is a
"proper" patch, and I'll get it tested and added too?
--
Jens Axboe
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