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b=uLZMn7KA++G0+Wly/p3EpL9zqxKe0qYTayOo+i7GlkAbp6El+s8w5g6j50qRIrzsB NkYFV0FK9f+79Kwz7dUXZr3STxNt5tUWMW6dq2PHEnf5xMBp23MmsxaVCGiCXzZBAh BPZE9ukoxmE0oFJs0649LDIW8p/c9gV26lJ6zB0oyHIoU94AmQkwKqVibLnI7BFNHs dVynjwklYnOFd51/LcSdDtWwK7k+hxUyMZqO2SO9KzG+Z6bJKIX/ePnDWYu0mV3V01 beLgsDaB37hJvQwaKJqq4PS62EwPUOrYwkr8HsflP1mT0Mv6NQ1d7TZ4YVxQ3Z/phR TO3qHn/VTYYxw== Date: Thu, 19 Mar 2026 12:43:16 -0700 From: Minchan Kim To: Sergey Senozhatsky Cc: Andrew Morton , Brian Geffon , Richard Chang , linux-block@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] zram: do not slot_free() written-back slots Message-ID: References: <20260319034912.1894770-1-senozhatsky@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260319034912.1894770-1-senozhatsky@chromium.org> X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 4E0CB180006 X-Stat-Signature: ux5jmexmferuf6eibuz43tqt4b6akjpo X-Rspam-User: X-HE-Tag: 1773949399-881513 X-HE-Meta: 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 oD4QkRwn 5t3KoB3R7GIhykFQC5It756XZmN38C5zf+OrTi1WbP7cpFCVt9fJ3iSQrJBa7zAR0UezJQBB+dQX1bAfIG0prlwAZw5N6WG5W21CaXIjjP2ghIjne43deXxfHscu1HZfRGz32GI8GWRg66+vTsaOreO4L9xWpNAnbnuUPMYKGAwyR1KJQExkJHZnyOQwvrjvRyiiZwLlHH9K0kHwyMT6Mj/17beIyeZuD8qOnrmGfLmej9VeR7fIcZghpp1LRED8tpnooKdClcg1dtgRzmYc/aqtwo4DVra6yqltcSguTFuZ+MF/qrQxDJGnJapdh4efZJQYB95a5LTSBt972lTivv+XUPQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Mar 19, 2026 at 12:44:56PM +0900, Sergey Senozhatsky wrote: > slot_free() basically completely resets the slots by clearing > all of its flags and attributes. While zram_writeback_complete() > restores some of flags back (those that are necessary for async > read decompression) we still lose a lot of slot's metadata. For > example, slot's ac-time, or ZRAM_INCOMPRESSIBLE. > > Do not slot_free() on writeback, instead clear only those > flags/attrs that we need to clear. > > Fixes: d38fab605c667 ("zram: introduce compressed data writeback") > Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim With small nit about the description in previous comment,