Re: [PATCH 3/5] zram: use zram_slot_lock instead of raw bit_spin_lock op

From	Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 3/5] zram: use zram_slot_lock instead of raw bit_spin_lock op
Date	2017-04-03 10:10 +0200
Message-ID	<ts5dM-4gF-9@gated-at.bofh.it> (permalink)
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On (04/03/17 15:34), Minchan Kim wrote:
[..]
> > c) spin_locks probably have better fairness guarantees
> 
> In fact, it wouldn't be an imporant because zram's slot lock contention
> is not heavy.

mostly agree. I think (and I may be mistaken) direct IO
causes contention; but direct IO is probably not a usual
zram workload.

> > what do you think? can we, in this patch set, also replce bit
> > spin_locks with a normal spin_lock?
> 
> With changing only zram side from bit_spin_lock to spin_lock,
> it would be crippled. I mean zsmalloc should be changed, too
> and it's really hard. :(

hm, good point.

	-ss

Thread

[PATCH 3/5] zram: use zram_slot_lock instead of raw bit_spin_lock op Minchan Kim <minchan@kernel.org> - 2017-04-03 07:20 +0200
  Re: [PATCH 3/5] zram: use zram_slot_lock instead of raw  bit_spin_lock op Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-04-03 08:10 +0200
    Re: [PATCH 3/5] zram: use zram_slot_lock instead of raw  bit_spin_lock op Minchan Kim <minchan@kernel.org> - 2017-04-03 08:40 +0200
      Re: [PATCH 3/5] zram: use zram_slot_lock instead of raw  bit_spin_lock op Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-04-03 10:10 +0200
  Re: [PATCH 3/5] zram: use zram_slot_lock instead of raw  bit_spin_lock op Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-04-04 04:20 +0200
    Re: [PATCH 3/5] zram: use zram_slot_lock instead of raw  bit_spin_lock op Minchan Kim <minchan@kernel.org> - 2017-04-04 07:00 +0200

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