Message-ID: <dd2b009a-cc8b-4f21-b248-64e909830bc0@gmail.com>
Date: Wed, 2 Jul 2025 23:53:48 +0200
From: Ferry Toth <fntoth@...il.com>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
 Alexander Kochetkov <al.kochet@...il.com>
Cc: Vinod Koul <vkoul@...nel.org>, dmaengine@...r.kernel.org,
 linux-kernel@...r.kernel.org, Nishad Saraf <nishads@....com>,
 Lizhi Hou <lizhi.hou@....com>, Jacky Huang <ychuang3@...oton.com>,
 Shan-Chun Hung <schung@...oton.com>,
 Florian Fainelli <florian.fainelli@...adcom.com>, Ray Jui
 <rjui@...adcom.com>, Scott Branden <sbranden@...adcom.com>,
 Lars-Peter Clausen <lars@...afoo.de>, Paul Cercueil <paul@...pouillou.net>,
 Eugeniy Paltsev <Eugeniy.Paltsev@...opsys.com>,
 Manivannan Sadhasivam <mani@...nel.org>, Frank Li <Frank.Li@....com>,
 Zhou Wang <wangzhou1@...ilicon.com>, Longfang Liu <liulongfang@...wei.com>,
 Andy Shevchenko <andy@...nel.org>, Shawn Guo <shawnguo@...nel.org>,
 Sascha Hauer <s.hauer@...gutronix.de>,
 Pengutronix Kernel Team <kernel@...gutronix.de>,
 Fabio Estevam <festevam@...il.com>, Keguang Zhang <keguang.zhang@...il.com>,
 Sean Wang <sean.wang@...iatek.com>, Matthias Brugger
 <matthias.bgg@...il.com>,
 AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>,
 Andreas Färber <afaerber@...e.de>,
 Daniel Mack <daniel@...que.org>, Haojian Zhuang <haojian.zhuang@...il.com>,
 Robert Jarzmik <robert.jarzmik@...e.fr>,
 Paul Walmsley <paul.walmsley@...ive.com>,
 Samuel Holland <samuel.holland@...ive.com>, Orson Zhai
 <orsonzhai@...il.com>, Baolin Wang <baolin.wang@...ux.alibaba.com>,
 Chunyan Zhang <zhang.lyra@...il.com>,
 Patrice Chotard <patrice.chotard@...s.st.com>,
 Amélie Delaunay <amelie.delaunay@...s.st.com>,
 Maxime Coquelin <mcoquelin.stm32@...il.com>,
 Alexandre Torgue <alexandre.torgue@...s.st.com>, Chen-Yu Tsai
 <wens@...e.org>, Jernej Skrabec <jernej.skrabec@...il.com>,
 Laxman Dewangan <ldewangan@...dia.com>, Jon Hunter <jonathanh@...dia.com>,
 Thierry Reding <thierry.reding@...il.com>,
 Peter Ujfalusi <peter.ujfalusi@...il.com>,
 Kunihiko Hayashi <hayashi.kunihiko@...ionext.com>,
 Masami Hiramatsu <mhiramat@...nel.org>, Dave Jiang <dave.jiang@...el.com>,
 Amit Vadhavana <av2082000@...il.com>,
 Uwe Kleine-König <u.kleine-koenig@...libre.com>,
 Ulf Hansson <ulf.hansson@...aro.org>, Md Sadre Alam
 <quic_mdalam@...cinc.com>, Casey Connolly <casey.connolly@...aro.org>,
 Kees Cook <kees@...nel.org>, Fenghua Yu <fenghua.yu@...el.com>,
 Jyothi Kumar Seerapu <quic_jseerapu@...cinc.com>
Subject: Re: [PATCH v2 1/2] dmaengine: virt-dma: convert tasklet to BH
 workqueue for callback invocation

Op 23-06-2025 om 12:39 schreef Andy Shevchenko:
> On Mon, Jun 16, 2025 at 12:48:03PM +0000, Alexander Kochetkov wrote:
>> Currently DMA callbacks are called from tasklet. However the tasklet is
>> marked deprecated and must be replaced by BH workqueue. Tasklet callbacks
>> are executed either in the Soft IRQ context or from ksoftirqd thread. BH
>> workqueue work items are executed in the BH context. Changing tasklet to
>> BH workqueue improved DMA callback latencies.
>>
>> The commit changes virt-dma driver and all of its users:
>> - tasklet is replaced to work_struct, tasklet callback updated accordingly
>> - kill_tasklet() is replaced to cancel_work_sync()
>> - added include of linux/interrupt.h where necessary
> 
> ...
> 
>>   drivers/dma/hsu/hsu.c                          |  2 +-
>>   drivers/dma/idma64.c                           |  3 ++-
> 
> Acked-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> for the above two.

With and without PREEMPT_RT (on Intel Edison) same 2 drivers.

Tested-by: Ferry Toth <fntoth@...il.com> # for Merrifield

Powered by blists - more mailing lists