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From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: Jeff Brown <jeffbrown@android.com>
Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 4/4] input: evdev: only wake poll on EV_SYN
Date: Fri, 25 Mar 2011 00:49:20 -0700	[thread overview]
Message-ID: <20110325074920.GF2590@core.coreip.homeip.net> (raw)
In-Reply-To: <1300842244-42723-5-git-send-email-jeffbrown@android.com>

On Tue, Mar 22, 2011 at 06:04:04PM -0700, Jeff Brown wrote:
> On SMP systems, it is possible for an evdev client blocked on poll()
> to wake up and read events from the evdev ring buffer at the same
> rate as they are enqueued.  This can result in high CPU usage,
> particularly for MT devices, because the client ends up reading
> events one at a time instead of reading complete packets.  This patch
> ensures that the client only wakes from poll() when a complete packet
> is ready to be read.

Doesn't this only help with very first packet after a pause in event
stream?

-- 
Dmitry

  reply	other threads:[~2011-03-25  7:49 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-23  1:04 [PATCH 0/4] input: Sizing the evdev ring buffer for MT devices and reporting overruns Jeff Brown
2011-03-23  1:04 ` [PATCH 1/4] input: Set default events per packet Jeff Brown
2011-03-25  8:20   ` Henrik Rydberg
2011-03-25 23:30     ` Jeffrey Brown
2011-03-28  7:10       ` Henrik Rydberg
2011-03-23  1:04 ` [PATCH 2/4] hid: hid-input: Remove obsolete default events per packet setting Jeff Brown
2011-03-23  1:04 ` [PATCH 3/4] input: evdev: Indicate buffer overrun with SYN_DROPPED Jeff Brown
2011-03-25  7:47   ` Dmitry Torokhov
2011-03-25  8:14   ` Henrik Rydberg
2011-03-25  9:02   ` Henrik Rydberg
     [not found]     ` <AANLkTike4c7SaeAm5JVWcLyZYt1K59OUEk94rnPeRkMy@mail.gmail.com>
2011-03-25 23:10       ` Jeffrey Brown
2011-03-25 23:12     ` Jeffrey Brown
2011-03-23  1:04 ` [PATCH 4/4] input: evdev: only wake poll on EV_SYN Jeff Brown
2011-03-25  7:49   ` Dmitry Torokhov [this message]
2011-03-25 23:03     ` Jeffrey Brown
2011-03-28  6:12       ` Dmitry Torokhov
2011-03-28  8:54         ` Jeffrey Brown
2011-03-25  8:34   ` Henrik Rydberg
2011-03-25 23:07     ` Jeffrey Brown

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