From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mike Snitzer <snitzer@redhat.com>
Subject: Re: dm: add swap_slot_free_notify handler
Date: Wed, 21 Sep 2016 20:14:28 -0400
Message-ID: <20160922001428.GA12676@redhat.com>
References: <1474499386-27436-1-git-send-email-wonhong.kwon@lge.com>
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To: Wonhong Kwon <wonhong.kwon@lge.com>
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On Wed, Sep 21 2016 at  7:09pm -0400,
Wonhong Kwon <wonhong.kwon@lge.com> wrote:

> swap_slot_free_notify callback has been added to block_device_operations to
> allow freeing memory allocated by RAM-based swap device like zram or zswap
> more aggressively.
> 
> In case of device mapper, it is also required if mapped target is being
> used as swap device and it uses some in-memory metadata for swap entries.
> This patch introduces swap_slot_free_notify callback into dm_blk_ops and
> target device can implement its own handler to handle this via
> slot_free_notify in target_type.
> 
> Signed-off-by: Wonhong Kwon <wonhong.kwon@lge.com>

This change to DM core only makes sense once we have an upstream DM
target that implements slot_free_notify hook.