On 9/24/18 7:59 PM, Eric Blake wrote:
On 9/21/18 12:23 PM, Leonid Bloch wrote:
Signed-off-by: Leonid Bloch <lbl...@janustech.com>
Reviewed-by: Alberto Garcia <be...@igalia.com>
---
block/qcow2.c | 2 +-
block/qcow2.h | 9 +++++----
2 files changed, 6 insertions(+), 5 deletions(-)
+++ b/block/qcow2.h
@@ -27,6 +27,7 @@
#include "crypto/block.h"
#include "qemu/coroutine.h"
+#include "qemu/units.h"
//#define DEBUG_ALLOC
//#define DEBUG_ALLOC2
@@ -43,11 +44,11 @@
/* 8 MB refcount table is enough for 2 PB images at 64k cluster size
* (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
-#define QCOW_MAX_REFTABLE_SIZE 0x800000
+#define QCOW_MAX_REFTABLE_SIZE S_8MiB
Why not (8 * MiB)? Where does this get stringified that you have to
introduce a new macro? Can we instead fix the stringification location
to call a convenience helper that converts arbitrary values into
convenient strings at runtime, rather than having to worry about a
separate macro just for stringification purposes?
- Why not (8 * MiB)?
Because we have the lookup table from the previous patch.
- Why do we need this table?
Because some values (not this one specifically, but for example
DEFAULT_CLUSTER_SIZE) get stringified at compile time (not during
runtime), and for these values the only two options are to use such a
table for convenient writing, or to write the number of bytes explicitly
in the definition.
Again, while the necessity for such a table comes from stringification,
it has an added value of short and clear size definitions.
/* 32 MB L1 table is enough for 2 PB images at 64k cluster size
* (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
-#define QCOW_MAX_L1_SIZE 0x2000000
+#define QCOW_MAX_L1_SIZE S_32MiB
Again, why not (32 * MiB)?
Same as above.
/* Allow for an average of 1k per snapshot table entry, should be
plenty of
* space for snapshot names and IDs */
@@ -75,9 +76,9 @@
/* Whichever is more */
#define DEFAULT_L2_CACHE_CLUSTERS 8 /* clusters */
-#define DEFAULT_L2_CACHE_BYTE_SIZE 1048576 /* bytes */
+#define DEFAULT_L2_CACHE_SIZE S_1MiB
and (1 * MiB)
Same as above.
-#define DEFAULT_CLUSTER_SIZE 65536
+#define DEFAULT_CLUSTER_SIZE S_64KiB
and (64 * KiB)
Because:
block/qcow2.c
4726: .def_value_str = stringify(DEFAULT_CLUSTER_SIZE)
(and similar in some other files).
Leonid.
