[PATCH v2] block/blk-iocost (gcc13): move large values to a new enum

From: Jiri Slaby (SUSE)
Date: Tue Dec 13 2022 - 06:22:09 EST


Since gcc13, each member of an enum has the same type as the enum [1]. And
that is inherited from its members. Provided:
VTIME_PER_SEC_SHIFT = 37,
VTIME_PER_SEC = 1LLU << VTIME_PER_SEC_SHIFT,
the named type is unsigned long.

This generates warnings with gcc-13:
block/blk-iocost.c: In function 'ioc_weight_prfill':
block/blk-iocost.c:3037:37: error: format '%u' expects argument of type 'unsigned int', but argument 4 has type 'long unsigned int'

block/blk-iocost.c: In function 'ioc_weight_show':
block/blk-iocost.c:3047:34: error: format '%u' expects argument of type 'unsigned int', but argument 3 has type 'long unsigned int'

So move the large VTIME values away to a separate enum, so that they
don't affect other members. Move also VRATE ones as they depend on
VTIME.

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36113

Cc: Martin Liska <mliska@xxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Josef Bacik <josef@xxxxxxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: cgroups@xxxxxxxxxxxxxxx
Cc: linux-block@xxxxxxxxxxxxxxx
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@xxxxxxxxxx>
---

Notes:
[v2] move to a new enum

block/blk-iocost.c | 48 ++++++++++++++++++++++++----------------------
1 file changed, 25 insertions(+), 23 deletions(-)

diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index d1bdc12deaa7..49d6e5aec3d5 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -233,29 +233,6 @@ enum {
/* 1/64k is granular enough and can easily be handled w/ u32 */
WEIGHT_ONE = 1 << 16,

- /*
- * As vtime is used to calculate the cost of each IO, it needs to
- * be fairly high precision. For example, it should be able to
- * represent the cost of a single page worth of discard with
- * suffificient accuracy. At the same time, it should be able to
- * represent reasonably long enough durations to be useful and
- * convenient during operation.
- *
- * 1s worth of vtime is 2^37. This gives us both sub-nanosecond
- * granularity and days of wrap-around time even at extreme vrates.
- */
- VTIME_PER_SEC_SHIFT = 37,
- VTIME_PER_SEC = 1LLU << VTIME_PER_SEC_SHIFT,
- VTIME_PER_USEC = VTIME_PER_SEC / USEC_PER_SEC,
- VTIME_PER_NSEC = VTIME_PER_SEC / NSEC_PER_SEC,
-
- /* bound vrate adjustments within two orders of magnitude */
- VRATE_MIN_PPM = 10000, /* 1% */
- VRATE_MAX_PPM = 100000000, /* 10000% */
-
- VRATE_MIN = VTIME_PER_USEC * VRATE_MIN_PPM / MILLION,
- VRATE_CLAMP_ADJ_PCT = 4,
-
/* if IOs end up waiting for requests, issue less */
RQ_WAIT_BUSY_PCT = 5,

@@ -310,6 +287,31 @@ enum {
LCOEF_RANDIO_PAGES = 4096,
};

+enum {
+ /*
+ * As vtime is used to calculate the cost of each IO, it needs to
+ * be fairly high precision. For example, it should be able to
+ * represent the cost of a single page worth of discard with
+ * suffificient accuracy. At the same time, it should be able to
+ * represent reasonably long enough durations to be useful and
+ * convenient during operation.
+ *
+ * 1s worth of vtime is 2^37. This gives us both sub-nanosecond
+ * granularity and days of wrap-around time even at extreme vrates.
+ */
+ VTIME_PER_SEC_SHIFT = 37,
+ VTIME_PER_SEC = 1LLU << VTIME_PER_SEC_SHIFT,
+ VTIME_PER_USEC = VTIME_PER_SEC / USEC_PER_SEC,
+ VTIME_PER_NSEC = VTIME_PER_SEC / NSEC_PER_SEC,
+
+ /* bound vrate adjustments within two orders of magnitude */
+ VRATE_MIN_PPM = 10000, /* 1% */
+ VRATE_MAX_PPM = 100000000, /* 10000% */
+
+ VRATE_MIN = VTIME_PER_USEC * VRATE_MIN_PPM / MILLION,
+ VRATE_CLAMP_ADJ_PCT = 4,
+};
+
enum ioc_running {
IOC_IDLE,
IOC_RUNNING,
--
2.39.0