From: Vinod Koul <vkoul@kernel.org>
To: Jean-Nicolas Graux <jean-nicolas.graux@st.com>
Cc: dmaengine@vger.kernel.org,
Linus Walleij <linus.walleij@linaro.org>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] dmaengine: pl08x: be fair when re-assigning physical channel
Date: Mon, 25 Mar 2019 10:43:41 +0530 [thread overview]
Message-ID: <20190325051341.GK5348@vkoul-mobl> (raw)
In-Reply-To: <1551711838-19913-1-git-send-email-jean-nicolas.graux@st.com>
On 04-03-19, 16:03, Jean-Nicolas Graux wrote:
> Current way we find a waiting virtual channel for the next transfer
> at the time one physical channel becomes free is not really fair.
>
> More in details, in case there is more than one channel waiting at a time,
> by just going through the arrays of memcpy and slave channels and stopping
> as soon as state match waiting state, channels with high indexes can be
> penalized.
>
> Whenever dma engine is substantially overloaded so that we constantly
> get several channels waiting, channels with highest indexes might not
> be served for a substantial time which in the worse case, might hang
> task that wait for dma transfer to complete.
>
> This patch makes physical channel re-assignment more fair by storing
> time in jiffies when a channel is put in waiting state. Whenever a
> physical channel has to be re-assigned, this time is used to select
> channel that is waiting for the longest time.
Applied, thanks
--
~Vinod
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next prev parent reply other threads:[~2019-03-25 5:14 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-04 15:03 [PATCH] dmaengine: pl08x: be fair when re-assigning physical channel Jean-Nicolas Graux
2019-03-25 5:13 ` Vinod Koul [this message]
2019-03-25 8:15 ` Jean Nicolas GRAUX
-- strict thread matches above, loose matches on Subject: below --
2019-03-01 16:18 Jean-Nicolas Graux
2019-03-04 10:00 ` Linus Walleij
2019-03-04 10:37 ` Jean Nicolas GRAUX
2019-03-04 12:05 ` Linus Walleij
2019-03-04 13:59 ` Jean Nicolas GRAUX
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