From: "Matwey V. Kornilov" <matwey@sai.msu.ru>
To: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: matwey.kornilov@gmail.com,
"Matwey V. Kornilov" <matwey@sai.msu.ru>,
tfiga@chromium.org, laurent.pinchart@ideasonboard.com,
stern@rowland.harvard.edu, ezequiel@collabora.com,
hdegoede@redhat.com, hverkuil@xs4all.nl, mchehab@kernel.org,
rostedt@goodmis.org, mingo@redhat.com, isely@pobox.com,
bhumirks@gmail.com, colin.king@canonical.com,
kieran.bingham@ideasonboard.com, keiichiw@chromium.org
Subject: [PATCH v5 0/2] media: usb: pwc: Don't use coherent DMA buffers for ISO transfer
Date: Tue, 21 Aug 2018 20:06:27 +0300 [thread overview]
Message-ID: <20180821170629.18408-1-matwey@sai.msu.ru> (raw)
DMA cocherency slows the transfer down on systems without hardware coherent
DMA. In order to demontrate this we introduce performance measurement
facilities in patch 1 and fix the performance issue in patch 2 in order to
obtain 4 times speedup.
Changes since v4:
* fix fields order in trace events
* minor style fixes
Changes since v3:
* fix scripts/checkpatch.pl errors
* use __string to store name in trace events
Changes since v2:
* use dma_sync_single_for_cpu() to achive better performance
* remeasured performance
Changes since v1:
* trace_pwc_handler_exit() call moved to proper place
* detailed description added for commit 1
* additional output added to trace to track separate frames
Matwey V. Kornilov (2):
media: usb: pwc: Introduce TRACE_EVENTs for pwc_isoc_handler()
media: usb: pwc: Don't use coherent DMA buffers for ISO transfer
drivers/media/usb/pwc/pwc-if.c | 64 ++++++++++++++++++++++++++++++++---------
include/trace/events/pwc.h | 65 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 116 insertions(+), 13 deletions(-)
create mode 100644 include/trace/events/pwc.h
--
2.16.4
next reply other threads:[~2018-08-21 17:36 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-21 17:06 Matwey V. Kornilov [this message]
2018-08-21 17:06 ` [PATCH v5 1/2] media: usb: pwc: Introduce TRACE_EVENTs for pwc_isoc_handler() Matwey V. Kornilov
2018-08-21 19:49 ` Steven Rostedt
2018-08-21 17:06 ` [PATCH v5 2/2] media: usb: pwc: Don't use coherent DMA buffers for ISO transfer Matwey V. Kornilov
2018-08-28 7:17 ` Matwey V. Kornilov
2018-09-11 18:58 ` Matwey V. Kornilov
2018-09-19 16:12 ` Ezequiel Garcia
2018-10-10 21:13 ` Matwey V. Kornilov
2018-10-30 22:00 ` Laurent Pinchart
2018-10-31 5:38 ` Christoph Hellwig
2018-12-07 15:25 ` Christoph Hellwig
2018-12-12 8:57 ` Tomasz Figa
2018-12-12 9:09 ` Christoph Hellwig
2018-12-12 9:34 ` Tomasz Figa
2018-12-12 13:54 ` Christoph Hellwig
2018-12-13 3:13 ` Tomasz Figa
2018-12-13 14:03 ` Christoph Hellwig
2018-12-14 3:12 ` Tomasz Figa
2018-12-14 12:36 ` Christoph Hellwig
2018-12-18 7:22 ` Tomasz Figa
2018-12-18 7:38 ` Christoph Hellwig
2018-12-18 9:48 ` Tomasz Figa
2018-12-19 7:51 ` Christoph Hellwig
2018-12-19 8:18 ` Tomasz Figa
2018-12-19 14:51 ` Christoph Hellwig
2018-12-20 3:23 ` Tomasz Figa
2018-12-21 8:13 ` Christoph Hellwig
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