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Date:   Mon, 18 Mar 2019 15:29:16 +0100
From:   Michal Hocko <mhocko@kernel.org>
To:     Pankaj Suryawanshi <pankaj.suryawanshi@einfochips.com>
Cc:     "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "minchan@kernel.org" <minchan@kernel.org>,
        Kirill Tkhai <ktkhai@virtuozzo.com>
Subject: Re: [External] Re: mm/cma.c: High latency for cma allocation
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On Mon 18-03-19 14:02:09, Pankaj Suryawanshi wrote:
>> > I have the system(vanilla kernel) with 2GB of RAM, reserved 1GB for CMA. No swap or zram.
>> > Sorry, I don't have information where the time is spent.
>> > time is calculated in between cma_alloc call.
>> > I have just cma_alloc trace information/function graph.
> 
>> Then please collect that data because it is really hard to judge
>> anything from the numbers you have provided.
>
> Any pointers from which i can get this details ?

I would start by enabling built in tracepoints for the migration or use
a system wide perf monitoring with call graph data.
-- 
Michal Hocko
SUSE Labs