[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 1/1] block: Eliminate the S_1KiB, S_2KiB, ... ma
From: |
Philippe Mathieu-Daudé |
Subject: |
Re: [Qemu-devel] [PATCH 1/1] block: Eliminate the S_1KiB, S_2KiB, ... macros |
Date: |
Mon, 14 Jan 2019 11:36:51 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.1 |
On 1/13/19 10:41 AM, Leonid Bloch wrote:
> On 1/11/19 9:14 PM, Markus Armbruster wrote:
>> We define 54 macros for the powers of two >= 1024. We use six, in six
>> macro definitions. Four of them could just as well use the common MiB
>> macro, so do that. The remaining two can't, because they get passed
>> to stringify. Replace the macro by the literal number there.
>> Slightly harder to read in one instance (1048576 vs. S_1MiB), so add a
>> comment there. The other instance is a wash: 65536 vs S_64KiB. 65536
>> has been good enough for more than seven years there.
>>
>> This effectively reverts commit 540b8492618 and 1240ac558d3.
>>
>> Signed-off-by: Markus Armbruster <address@hidden>
>> ---
>> block/qcow2.h | 10 +++---
>> block/vdi.c | 3 +-
>> include/qemu/units.h | 73 --------------------------------------------
>> 3 files changed, 7 insertions(+), 79 deletions(-)
>>
>> diff --git a/block/qcow2.h b/block/qcow2.h
>> index a98d24500b..2380cbfb41 100644
>> --- a/block/qcow2.h
>> +++ b/block/qcow2.h
>> @@ -50,11 +50,11 @@
>>
>> /* 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 S_8MiB
>> +#define QCOW_MAX_REFTABLE_SIZE (8 * MiB)
>>
>> /* 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 S_32MiB
>> +#define QCOW_MAX_L1_SIZE (32 * MiB)
>>
>> /* Allow for an average of 1k per snapshot table entry, should be plenty of
>> * space for snapshot names and IDs */
>> @@ -81,15 +81,15 @@
>> #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
>>
>> #ifdef CONFIG_LINUX
>> -#define DEFAULT_L2_CACHE_MAX_SIZE S_32MiB
>> +#define DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB)
>> #define DEFAULT_CACHE_CLEAN_INTERVAL 600 /* seconds */
>> #else
>> -#define DEFAULT_L2_CACHE_MAX_SIZE S_8MiB
>> +#define DEFAULT_L2_CACHE_MAX_SIZE (8 * MiB)
>> /* Cache clean interval is currently available only on Linux, so must be 0
>> */
>> #define DEFAULT_CACHE_CLEAN_INTERVAL 0
>> #endif
>>
>> -#define DEFAULT_CLUSTER_SIZE S_64KiB
>> +#define DEFAULT_CLUSTER_SIZE 65536
>
> /* Note: can't use 64 * KiB here, because it's passed to stringify() */
Good idea.
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
> Otherwise fine with me. The other solutions (including mine) indeed seem
> overengineered compared to this.
>
> Leonid.
>
>>
>> #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
>> #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
>> diff --git a/block/vdi.c b/block/vdi.c
>> index 2380daa583..bf1d19dd68 100644
>> --- a/block/vdi.c
>> +++ b/block/vdi.c
>> @@ -85,7 +85,8 @@
>> #define BLOCK_OPT_STATIC "static"
>>
>> #define SECTOR_SIZE 512
>> -#define DEFAULT_CLUSTER_SIZE S_1MiB
>> +#define DEFAULT_CLUSTER_SIZE 1048576
>> +/* Note: can't use 1 * MiB, because it's passed to stringify() */
>>
>> #if defined(CONFIG_VDI_DEBUG)
>> #define VDI_DEBUG 1
>> diff --git a/include/qemu/units.h b/include/qemu/units.h
>> index 1c959d182e..692db3fbb2 100644
>> --- a/include/qemu/units.h
>> +++ b/include/qemu/units.h
>> @@ -17,77 +17,4 @@
>> #define PiB (INT64_C(1) << 50)
>> #define EiB (INT64_C(1) << 60)
>>
>> -/*
>> - * The following lookup table is intended to be used when a literal string
>> of
>> - * the number of bytes is required (for example if it needs to be
>> stringified).
>> - * It can also be used for generic shortcuts of power-of-two sizes.
>> - * This table is generated using the AWK script below:
>> - *
>> - * BEGIN {
>> - * suffix="KMGTPE";
>> - * for(i=10; i<64; i++) {
>> - * val=2**i;
>> - * s=substr(suffix, int(i/10), 1);
>> - * n=2**(i%10);
>> - * pad=21-int(log(n)/log(10));
>> - * printf("#define S_%d%siB %*d\n", n, s, pad, val);
>> - * }
>> - * }
>> - */
>> -
>> -#define S_1KiB 1024
>> -#define S_2KiB 2048
>> -#define S_4KiB 4096
>> -#define S_8KiB 8192
>> -#define S_16KiB 16384
>> -#define S_32KiB 32768
>> -#define S_64KiB 65536
>> -#define S_128KiB 131072
>> -#define S_256KiB 262144
>> -#define S_512KiB 524288
>> -#define S_1MiB 1048576
>> -#define S_2MiB 2097152
>> -#define S_4MiB 4194304
>> -#define S_8MiB 8388608
>> -#define S_16MiB 16777216
>> -#define S_32MiB 33554432
>> -#define S_64MiB 67108864
>> -#define S_128MiB 134217728
>> -#define S_256MiB 268435456
>> -#define S_512MiB 536870912
>> -#define S_1GiB 1073741824
>> -#define S_2GiB 2147483648
>> -#define S_4GiB 4294967296
>> -#define S_8GiB 8589934592
>> -#define S_16GiB 17179869184
>> -#define S_32GiB 34359738368
>> -#define S_64GiB 68719476736
>> -#define S_128GiB 137438953472
>> -#define S_256GiB 274877906944
>> -#define S_512GiB 549755813888
>> -#define S_1TiB 1099511627776
>> -#define S_2TiB 2199023255552
>> -#define S_4TiB 4398046511104
>> -#define S_8TiB 8796093022208
>> -#define S_16TiB 17592186044416
>> -#define S_32TiB 35184372088832
>> -#define S_64TiB 70368744177664
>> -#define S_128TiB 140737488355328
>> -#define S_256TiB 281474976710656
>> -#define S_512TiB 562949953421312
>> -#define S_1PiB 1125899906842624
>> -#define S_2PiB 2251799813685248
>> -#define S_4PiB 4503599627370496
>> -#define S_8PiB 9007199254740992
>> -#define S_16PiB 18014398509481984
>> -#define S_32PiB 36028797018963968
>> -#define S_64PiB 72057594037927936
>> -#define S_128PiB 144115188075855872
>> -#define S_256PiB 288230376151711744
>> -#define S_512PiB 576460752303423488
>> -#define S_1EiB 1152921504606846976
>> -#define S_2EiB 2305843009213693952
>> -#define S_4EiB 4611686018427387904
>> -#define S_8EiB 9223372036854775808
>> -
>> #endif
>>
Thanks Markus, Eric and Leonid for this cleanup!
I'm sorry all of you wasted so many ressources here.
Phil.
- [Qemu-devel] [PATCH 0/1] block: Eliminate the S_1KiB, S_2KiB, ... macros, Markus Armbruster, 2019/01/11
- Re: [Qemu-devel] [PATCH 0/1] block: Eliminate the S_1KiB, S_2KiB, ... macros, Leonid Bloch, 2019/01/13
- Re: [Qemu-devel] [PATCH 0/1] block: Eliminate the S_1KiB, S_2KiB, ... macros, Kevin Wolf, 2019/01/25