From: Bart Van Assche <bart.vanassche@wdc.com>
Date: Mon, 26 Mar 2018 16:00:28 +0000 (-0700)
Subject: Only populate the write buffer if necessary
X-Git-Tag: fio-3.6~18^2~3
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=5c5c33c1b0df088187a6d4fac5459df5e029763a

Only populate the write buffer if necessary

This patch moves the populate_verify_io_u() call from inside
get_io_u() into all its callers except do_dry_run() and thereby skips
write buffer population for dry runs. This patch does not change the
behavior of fio but is necessary because the ZBC patch will insert
code in fill_io_u() after the get_io_u() call that may modify the
write offset.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
---

diff --git a/backend.c b/backend.c
index f2d7cc36..b28c3dbc 100644
--- a/backend.c
+++ b/backend.c
@@ -723,6 +723,7 @@ static void do_verify(struct thread_data *td, uint64_t verify_bytes)
 					break;
 				} else if (io_u->ddir == DDIR_WRITE) {
 					io_u->ddir = DDIR_READ;
+					populate_verify_io_u(td, io_u);
 					break;
 				} else {
 					put_io_u(td, io_u);
@@ -995,6 +996,9 @@ static void do_io(struct thread_data *td, uint64_t *bytes_done)
 			break;
 		}
 
+		if (io_u->ddir == DDIR_WRITE && td->flags & TD_F_DO_VERIFY)
+			populate_verify_io_u(td, io_u);
+
 		ddir = io_u->ddir;
 
 		/*
diff --git a/io_u.c b/io_u.c
index d4a65089..5fbb2386 100644
--- a/io_u.c
+++ b/io_u.c
@@ -1699,7 +1699,7 @@ static void small_content_scramble(struct io_u *io_u)
 
 /*
  * Return an io_u to be processed. Gets a buflen and offset, sets direction,
- * etc. The returned io_u is fully ready to be prepped and submitted.
+ * etc. The returned io_u is fully ready to be prepped, populated and submitted.
  */
 struct io_u *get_io_u(struct thread_data *td)
 {
@@ -1760,12 +1760,9 @@ struct io_u *get_io_u(struct thread_data *td)
 					td->o.min_bs[DDIR_WRITE],
 					io_u->buflen);
 			} else if ((td->flags & TD_F_SCRAMBLE_BUFFERS) &&
-				   !(td->flags & TD_F_COMPRESS))
+				   !(td->flags & TD_F_COMPRESS) &&
+				   !(td->flags & TD_F_DO_VERIFY))
 				do_scramble = 1;
-			if (td->flags & TD_F_DO_VERIFY) {
-				populate_verify_io_u(td, io_u);
-				do_scramble = 0;
-			}
 		} else if (io_u->ddir == DDIR_READ) {
 			/*
 			 * Reset the buf_filled parameters so next time if the