Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Tue, 10 Mar 2020 09:01:16 +0000
From:   Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To:     SeongJae Park <sjpark@amazon.com>
CC:     <akpm@linux-foundation.org>, SeongJae Park <sjpark@amazon.de>,
        <aarcange@redhat.com>, <yang.shi@linux.alibaba.com>,
        <acme@kernel.org>, <alexander.shishkin@linux.intel.com>,
        <amit@kernel.org>, <brendan.d.gregg@gmail.com>,
        <brendanhiggins@google.com>, <cai@lca.pw>,
        <colin.king@canonical.com>, <corbet@lwn.net>, <dwmw@amazon.com>,
        <jolsa@redhat.com>, <kirill@shutemov.name>, <mark.rutland@arm.com>,
        <mgorman@suse.de>, <minchan@kernel.org>, <mingo@redhat.com>,
        <namhyung@kernel.org>, <peterz@infradead.org>,
        <rdunlap@infradead.org>, <rientjes@google.com>,
        <rostedt@goodmis.org>, <shuah@kernel.org>, <sj38.park@gmail.com>,
        <vbabka@suse.cz>, <vdavydov.dev@gmail.com>, <linux-mm@kvack.org>,
        <linux-doc@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v6 05/14] mm/damon: Implement callbacks
Message-ID: <20200310090116.0000723f@Huawei.com>
In-Reply-To: <20200224123047.32506-6-sjpark@amazon.com>
References: <20200224123047.32506-1-sjpark@amazon.com>
 <20200224123047.32506-6-sjpark@amazon.com>
Organization: Huawei Technologies Research and Development (UK) Ltd.
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Mon, 24 Feb 2020 13:30:38 +0100
SeongJae Park <sjpark@amazon.com> wrote:

> From: SeongJae Park <sjpark@amazon.de>
> 
> This commit implements callbacks for DAMON.  Using this, DAMON users can
> install their callbacks for each step of the access monitoring so that
> they can do something interesting with the monitored access pattrns

patterns

> online.  For example, callbacks can report the monitored patterns to
> users or do some access pattern based memory management such as
> proactive reclamations or access pattern based THP promotions/demotions
> decision makings.
> 
> Signed-off-by: SeongJae Park <sjpark@amazon.de>
> ---
>  mm/damon.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/mm/damon.c b/mm/damon.c
> index 6a17408e83c2..554720778e8a 100644
> --- a/mm/damon.c
> +++ b/mm/damon.c
> @@ -83,6 +83,10 @@ struct damon_ctx {
>  	struct rnd_state rndseed;
>  
>  	struct list_head tasks_list;	/* 'damon_task' objects */
> +
> +	/* callbacks */
> +	void (*sample_cb)(struct damon_ctx *context);
> +	void (*aggregate_cb)(struct damon_ctx *context);
>  };
>  
>  /* Get a random number in [l, r) */
> @@ -814,9 +818,13 @@ static int kdamond_fn(void *data)
>  			}
>  			mmput(mm);
>  		}
> +		if (ctx->sample_cb)
> +			ctx->sample_cb(ctx);
>  
>  		if (kdamond_aggregate_interval_passed(ctx)) {
>  			kdamond_merge_regions(ctx, max_nr_accesses / 10);
> +			if (ctx->aggregate_cb)
> +				ctx->aggregate_cb(ctx);
>  			kdamond_flush_aggregated(ctx);
>  			kdamond_split_regions(ctx);
>  		}