Recent changes (master)

[Jens Axboe <axboe@kernel.dk>]

The following changes since commit 1d282baecd689f4409449d5e5238b30990cec377:

  fio: make sure that child process output is comitted (2026-01-15 17:35:13 +0000)

are available in the Git repository at:

  git://git.kernel.dk/fio.git master

for you to fetch changes up to e2d1cce0f1c5617467f95ac2154212179451ba85:

  test: add test for switching to tausworthe64 (2026-01-15 21:02:38 -0500)

----------------------------------------------------------------
Vincent Fu (2):
      init: move random seed debug prints
      test: add test for switching to tausworthe64

 init.c             |  4 ++--
 t/run-fio-tests.py |  8 ++++++++
 t/t64-switch.sh    | 43 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+), 2 deletions(-)
 create mode 100755 t/t64-switch.sh

---

Diff of recent changes:

diff --git a/init.c b/init.c
index 8a0d8c20..5a982b53 100644
--- a/init.c
+++ b/init.c
@@ -1236,12 +1236,12 @@ static int setup_random_seeds(struct thread_data *td)
 		}
 	}
 
-	td_fill_rand_seeds(td);
-
 	dprint(FD_RANDOM, "FIO_RAND_NR_OFFS=%d\n", FIO_RAND_NR_OFFS);
 	for (int i = 0; i < FIO_RAND_NR_OFFS; i++)
 		dprint(FD_RANDOM, "rand_seeds[%d]=%" PRIu64 "\n", i, td->rand_seeds[i]);
 
+	td_fill_rand_seeds(td);
+
 	return 0;
 }
 
diff --git a/t/run-fio-tests.py b/t/run-fio-tests.py
index 457d7f8c..b3321312 100755
--- a/t/run-fio-tests.py
+++ b/t/run-fio-tests.py
@@ -1131,6 +1131,14 @@ TEST_LIST = [
         'success':          SUCCESS_DEFAULT,
         'requirements':     [Requirements.linux, Requirements.libaio],
     },
+    {
+        'test_id':          1020,
+        'test_class':       FioExeTest,
+        'exe':              't/t64-switch.sh',
+        'parameters':       ['{fio_path}'],
+        'success':          SUCCESS_DEFAULT,
+        'requirements':     [Requirements.not_windows],
+    },
 ]
 
 
diff --git a/t/t64-switch.sh b/t/t64-switch.sh
new file mode 100755
index 00000000..94b12754
--- /dev/null
+++ b/t/t64-switch.sh
@@ -0,0 +1,43 @@
+#!/usr/bin/env bash
+#
+# Make sure that Fio actually does switch to the tausworthe64 random generator
+# when it detects that the combination of block size and file size exceeds the
+# limits of the default 32-bit random generator.
+#
+# Do this by counting the number of times offsets occurring more than once are
+# touched. The default random generator should produce more duplicate offsets
+# than the tausworthe64 random generator.
+#
+# Count offsets by parsing Fio's debug output. Use grep and cut to obtain a
+# list of offsets, sort them, and count how many times offsets ocurring more
+# than once are touched.
+#
+# Calculate the ratio of tausworthe32 duplicates to tausworthe64 duplicates. I
+# am arbitrarily using a minimum ratio of 10 as the criteria for a passing
+# test.
+#
+# Usage:
+# t64-switch [FIO [COUNT]]
+#
+
+FIO=${1:-fio}
+COUNT=${2:-1000000}
+
+t32=$(${FIO} --name=test --ioengine=null --filesize=1T --bs=1 --rw=randread --debug=io --number_ios=${COUNT} --norandommap --randrepeat=0 --random_generator=tausworthe | grep complete: | cut -d '=' -f 2 | cut -d ',' -f 1 | sort -g | uniq -D | wc -l | tr -d ' ')
+t64=$(${FIO} --name=test --ioengine=null --filesize=1T --bs=1 --rw=randread --debug=io --number_ios=${COUNT} --norandommap --randrepeat=0 | grep complete: | cut -d '=' -f 2 | cut -d ',' -f 1 | sort -g | uniq -D | wc -l | tr -d ' ')
+if [ $t64 -gt 0 ]; then
+	let ratio=$t32/$t64
+else
+	let ratio=$t32
+fi
+
+echo tausworthe32: $t32
+echo tausworthe62: $t64
+echo ratio: $ratio
+
+if [ $ratio -ge 10 ]; then
+	echo result: pass
+else
+	echo result: fail
+	exit 1
+fi