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Sender: Minchan Kim <minchan.kim@gmail.com>
Date:   Thu, 21 Jan 2021 16:19:22 -0800
From:   Minchan Kim <minchan@kernel.org>
To:     vjitta@codeaurora.org
Cc:     glider@google.com, akpm@linux-foundation.org,
        dan.j.williams@intel.com, broonie@kernel.org, mhiramat@kernel.org,
        linux-kernel@vger.kernel.org, ylal@codeaurora.org,
        vinmenon@codeaurora.org
Subject: Re: [PATCH v5 1/2] lib: stackdepot: Add support to configure
 STACK_HASH_SIZE
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References: <1610963802-11042-1-git-send-email-vjitta@codeaurora.org>
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On Mon, Jan 18, 2021 at 03:26:41PM +0530, vjitta@codeaurora.org wrote:
> From: Yogesh Lal <ylal@codeaurora.org>
> 
> Use CONFIG_STACK_HASH_ORDER to configure STACK_HASH_SIZE.
> 
> Aim is to have configurable value for  STACK_HASH_SIZE,
> so depend on use case one can configure it.
> 
> One example is of Page Owner, default value of
> STACK_HASH_SIZE lead stack depot to consume 8MB of static memory.
> Making it configurable and use lower value helps to enable features like
> CONFIG_PAGE_OWNER without any significant overhead.

The description could be improved to prevent confusing.
CONFIG_PAGE_OWNER works only if page_owner=on via kernel parameter
on CONFIG_PAGE_OWNER configured system.
Thus, unless admin enable it via command line option, the stackdepot
will just waste 8M memory without any customer.

> 
> Signed-off-by: Yogesh Lal <ylal@codeaurora.org>
> Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
> Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org>
Reviewed-by: Minchan Kim <minchan@kernel.org>