Re: [PATCH] zram: extra zram_get_element call in zram_read_from_zspool()

[Sergey Senozhatsky]

On (23/11/08 06:16), Vasily Averin wrote:
> 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'.

Yes, what the patch does is pretty clear. It doesn't *fix* anything per se.

> 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.

I do not agree with "union should be removed" part.

In this particular case - using handle as the page pattern (element)
is in fact quite confusing. The visual separation of `handle` and `element`
is helpful.