On 11/8/23 05:49, Sergey Senozhatsky wrote:
> On (23/11/06 22:55), Vasily Averin wrote:
>>
>> 'element' and 'handle' are union in struct zram_table_entry.
>>
>> Fixes: 8e19d540d107 ("zram: extend zero pages to same element pages")
>
> Sorry, what exactly does it fix?
It removes unneeded call of zram_get_element() and unneeded variable 'value'.
zram_get_element() == zram_get_handle(), they both access the same field of the same struct zram_table_entry,
no need to read it 2nd time.
'value' variable is not required, 'handle' can be used instead.
I hope this explain why element/handle union should be removed: it confuses reviewers.
> [..]
>> @@ -1318,12 +1318,10 @@ static int zram_read_from_zspool(struct zram *zram, struct page *page,
>>
>> handle = zram_get_handle(zram, index);
>> if (!handle || zram_test_flag(zram, index, ZRAM_SAME)) {
>> - unsigned long value;
>> void *mem;
>>
>> - value = handle ? zram_get_element(zram, index) : 0;
>> mem = kmap_atomic(page);
>> - zram_fill_page(mem, PAGE_SIZE, value);
>> + zram_fill_page(mem, PAGE_SIZE, handle);
>> kunmap_atomic(mem);
>> return 0;
>> }
