Re: [PATCH] zram: don't free statically defined names

From: Andrey Skvortsov
Date: Mon Sep 23 2024 - 11:55:19 EST


Hi Sergey,

On 24-09-24 00:47, Sergey Senozhatsky wrote:
> ** Re-sending properly, somehow I managed to badly mess up
> the headers the first time, sorry ***
>
>
> On (24/09/24 00:34), Sergey Senozhatsky wrote:
> > On (24/09/23 11:02), Andrey Skvortsov wrote:
> > > for (prio = ZRAM_SECONDARY_COMP; prio < ZRAM_MAX_COMPS; prio++) {
> > > - kfree(zram->comp_algs[prio]);
> > > + /* Do not free statically defined compression algorithms */
> >
> > We probably don't really need this comment.
> >
> > > + if (zram->comp_algs[prio] != default_compressor)
> > > + kfree(zram->comp_algs[prio]);
> > > zram->comp_algs[prio] = NULL;
> > > }
> >
> > OK, so... I wonder how do you get a `default_compressor` on a
> > non-ZRAM_PRIMARY_COMP prio. May I ask what's your reproducer?
> >
> > I didn't expect `default_compressor` on ZRAM_SECONDARY_COMP
> > and below. As far as I can tell, we only do this:
> >
> > comp_algorithm_set(zram, ZRAM_PRIMARY_COMP, default_compressor);
> >
> > in zram_reset_device() and zram_add(). So, how does it end up in
> > ZRAM_SECONDARY_COMP...
>
> Ugh, I know what's happening. You don't have CONFIG_ZRAM_MULTI_COMP
> so that ZRAM_PRIMARY_COMP and ZRAM_SECONDARY_COMP are the same thing.
> Yeah, that all makes sense now, I haven't thought about it.

yes, I don't have CONFIG_ZRAM_MULTI_COMP set. I'll include your
comment into commit description for v2.

> Can you please send v2 (with the feedback resolved).

--
Best regards,
Andrey Skvortsov