[PATCH blktests v5 3/3] doc: document how to configure bcache tests

Add a bcache entry in running-tests which explains how to configure
blktests for the bcache tests.

Signed-off-by: Daniel Wagner <[email protected]>
---
 Documentation/running-tests.md | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Documentation/running-tests.md b/Documentation/running-tests.md
index f9da042bb3a0..7d935aad3331 100644
--- a/Documentation/running-tests.md
+++ b/Documentation/running-tests.md
@@ -189,6 +189,16 @@ THROTL_BLKDEV_TYPES="sdebug" ./check throtl/
 THROTL_BLKDEV_TYPES="nullb sdebug" ./check throtl/
 ```
 
+### Bcache test configuration
+
+The bcache tests require multiple devices to run simultaneously. By default,
+blktests run each test case for each device in TEST_DEVS. This behavior
+prevents testing with multiple devices. The TEST_CASE_DEV_ARRAY resolves this by
+enabling multiple device configurations per test. Bcache tests need at
+least three devices, which can be specified in your configuration as follows:
+
+TEST_CASE_DEV_ARRAY[bcache/*]="/dev/nvme0n1 /dev/vdb /dev/vdc"
+
 ### Normal user
 
 To run test cases which require normal user privilege, prepare a user and

-- 
2.53.0