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Subject: Re: [PATCH] Add slowpath enter/exit trace events
To:     Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
        Mel Gorman <mgorman@techsingularity.net>,
        Michal Hocko <mhocko@kernel.org>
CC:     <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ingo Molnar <mingo@redhat.com>,
        Alex Deucher <alexander.deucher@amd.com>,
        "David S . Miller" <davem@davemloft.net>,
        Harry Wentland <Harry.Wentland@amd.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Tony Cheng <Tony.Cheng@amd.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Vlastimil Babka <vbabka@suse.cz>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Pavel Tatashin <pasha.tatashin@oracle.com>
References: <20171123104336.25855-1-peter.enderborg@sony.com>
 <20171123122530.ktsxgeakebfp3yep@dhcp22.suse.cz>
 <20171123133629.5sgmapfg7gix7pu3@techsingularity.net>
 <640b7de7-c216-de34-18e8-dc1aacd19f35@I-love.SAKURA.ne.jp>
From:   peter enderborg <peter.enderborg@sony.com>
Message-ID: <16719b9b-b7e2-3cce-299b-99215b79518f@sony.com>
Date:   Fri, 24 Nov 2017 08:43:47 +0100
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On 11/23/2017 02:43 PM, Tetsuo Handa wrote:
> Please see my attempt at
> http://lkml.kernel.org/r/1510833448-19918-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp .
> Printing just current thread is not sufficient for me.
>
>
Seems to� me that it is a lot more overhead with timers and stuff.
My probe is for the health of the system trying to capture how get the penalty and how much. A slowpath alloc in a audio stream can causes drop-outs. And they are very hard to debug in userspace.


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