Re: Memory unit GUC range checks

On 17/05/18 00:56, Alexander Korotkov wrote:
> On Wed, May 16, 2018 at 10:41 PM, Andres Freund <andres@anarazel.de> wrote:
> 
>> Generally ok, two minor points:
>>
>>> diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
>>> index 7cd2d2d80e..93402030f7 100644
>>>        {"TB", GUC_UNIT_BLOCKS, (1024 * 1024 * 1024) / (BLCKSZ / 1024)},
>>>        {"GB", GUC_UNIT_BLOCKS, (1024 * 1024) / (BLCKSZ / 1024)},
>>>        {"MB", GUC_UNIT_BLOCKS, 1024 / (BLCKSZ / 1024)},
>>>        {"kB", GUC_UNIT_BLOCKS, -(BLCKSZ / 1024)},
>>> +     {"B", GUC_UNIT_BLOCKS, -(BLCKSZ / (1024 * 1024))},
>>
>> Isn't this 0 in the common case of 8k pages?
>>
>>>        {"TB", GUC_UNIT_XBLOCKS, (1024 * 1024 * 1024) / (XLOG_BLCKSZ /
>> 1024)},
>>>        {"GB", GUC_UNIT_XBLOCKS, (1024 * 1024) / (XLOG_BLCKSZ / 1024)},
>>>        {"MB", GUC_UNIT_XBLOCKS, 1024 / (XLOG_BLCKSZ / 1024)},
>>>        {"kB", GUC_UNIT_XBLOCKS, -(XLOG_BLCKSZ / 1024)},
>>> +     {"B", GUC_UNIT_XBLOCKS, -(XLOG_BLCKSZ / (1024 * 1024))},
>>
>> Same?
> 
> As I understand, in these cases multiplier should be just -BLCKSZ and
> -XLOG_BLCKSZ correspondingly.

Yep, quite right. Fixed and committed, thanks!

- Heikki