Re: number_ios is checked on completion, not submission

[Jens Axboe <axboe@kernel.dk>]

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On 03/10/2014 03:12 PM, Elliott, Robert (Server Storage) wrote:
> Since number_ios is checked in io_u.c account_io_completion() rather than a submission function, fio actually runs the requested number of I/Os plus iodepth - 1.
>
> Example: for a job specifying:
> number_ios=5000
> iodepth=128
>
> the results are:
>    read : io=20000KB, bw=222222KB/s, iops=56966, runt=    90msec
>    IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.2%, 16=0.3%, 32=0.6%, >=64=98.8%
>       issued    : total=r=5127/w=0/d=0, short=r=0/w=0/d=0
>
> Should that just be documented as such, or should this logic be moved to submission?
> static void account_io_completion(struct thread_data *td, struct io_u *io_u,
> ...
>          if (td->o.number_ios && !--td->o.number_ios)
>                  td->done = 1;

Can you try the attached patch and see if that makes it behave more like 
expected?

-- 
Jens Axboe


[-- Attachment #2: number_ios.patch --]
[-- Type: text/x-patch, Size: 1420 bytes --]

diff --git a/backend.c b/backend.c
index 992033c5c170..cee185571082 100644
--- a/backend.c
+++ b/backend.c
@@ -625,6 +625,7 @@ reap:
 
 static int io_bytes_exceeded(struct thread_data *td)
 {
+	unsigned long long number_ios = 0;
 	unsigned long long bytes;
 
 	if (td_rw(td))
@@ -636,7 +637,13 @@ static int io_bytes_exceeded(struct thread_data *td)
 	else
 		bytes = td->this_io_bytes[DDIR_TRIM];
 
-	return bytes >= td->o.size;
+	if (td->o.number_ios) {
+		number_ios = ddir_rw_sum(td->this_io_blocks);
+		number_ios += td->io_u_queued;
+	}
+
+	return bytes >= td->o.size ||
+		(number_ios && number_ios >= td->o.number_ios);
 }
 
 /*
@@ -1128,6 +1135,14 @@ static int keep_running(struct thread_data *td)
 		return 1;
 	}
 
+	if (td->o.number_ios) {
+		unsigned long long number_ios = ddir_rw_sum(td->this_io_blocks);
+
+		number_ios += td->io_u_queued;
+		if (number_ios >= td->o.number_ios)
+			return 0;
+	}
+
 	if (td->o.size != -1ULL && ddir_rw_sum(td->io_bytes) < td->o.size) {
 		uint64_t diff;
 
diff --git a/io_u.c b/io_u.c
index 8e27708731c7..0b86d9f3c281 100644
--- a/io_u.c
+++ b/io_u.c
@@ -1595,9 +1595,6 @@ static void account_io_completion(struct thread_data *td, struct io_u *io_u,
 
 	if (!gtod_reduce(td))
 		add_iops_sample(td, idx, bytes, &icd->time);
-
-	if (td->o.number_ios && !--td->o.number_ios)
-		td->done = 1;
 }
 
 static long long usec_for_io(struct thread_data *td, enum fio_ddir ddir)