From: Ralf Baechle <ralf@linux-mips.org>
To: "Maciej W. Rozycki" <macro@imgtec.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>,
Matt Redfearn <Matt.Redfearn@imgtec.com>,
Aleksandar Markovic <aleksandar.markovic@rt-rk.com>,
"linux-mips@linux-mips.org" <linux-mips@linux-mips.org>,
James Hogan <James.Hogan@imgtec.com>,
Paul Burton <Paul.Burton@imgtec.com>,
Raghu Gandham <Raghu.Gandham@imgtec.com>,
Douglas Leung <Douglas.Leung@imgtec.com>,
Petar Jovanovic <Petar.Jovanovic@imgtec.com>,
Miodrag Dinic <Miodrag.Dinic@imgtec.com>,
Goran Ferenc <Goran.Ferenc@imgtec.com>
Subject: Re: [PATCH 3/8] MIPS: R6: Fix PREF instruction usage by memcpy for MIPS R6
Date: Wed, 28 Jun 2017 10:34:11 +0200 [thread overview]
Message-ID: <20170628083411.GD6738@linux-mips.org> (raw)
In-Reply-To: <alpine.DEB.2.00.1706280329280.31404@tp.orcam.me.uk>
On Wed, Jun 28, 2017 at 03:36:54AM +0100, Maciej W. Rozycki wrote:
> On Wed, 28 Jun 2017, Leonid Yegoshin wrote:
>
> > The bigger problem is a prefetch overrun to device registers. AT use is just
> > nuisance.
>
> That isn't however what the patch addresses, not at least according to
> the description provided.
>
> How far beyond the data copied do we prefetch anyway, and can't we simply
> waste a page's worth of space or so at the physical end of each RAM area
> present in a given system? Or perhaps use it for something we know for
> sure that won't ever be copied.
Prefetching may also bring data which has just been flushed back into
caches so until this is fixed properly it's not a good idea on non-coherent
platforms.
Ralf
next prev parent reply other threads:[~2017-06-28 8:34 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-19 15:50 [PATCH 0/8] MIPS: Miscellaneous fixes related to Android Mips emulator Aleksandar Markovic
2017-06-19 15:50 ` [PATCH 1/8] MIPS: cmdline: Add support for 'memmap' parameter Aleksandar Markovic
2017-06-19 15:50 ` [PATCH 2/8] MIPS: build: Fix "-modd-spreg" switch usage when compiling for mips32r6 Aleksandar Markovic
2017-06-19 15:50 ` [PATCH 3/8] MIPS: R6: Fix PREF instruction usage by memcpy for MIPS R6 Aleksandar Markovic
2017-06-20 8:04 ` Matt Redfearn
2017-06-20 8:04 ` Matt Redfearn
2017-06-28 0:58 ` Ralf Baechle
2017-06-28 1:35 ` Maciej W. Rozycki
2017-06-28 1:35 ` Maciej W. Rozycki
[not found] ` <9915e476-70fe-4281-a1e4-85ca2e8683b3@imgtec.com>
2017-06-28 2:36 ` Maciej W. Rozycki
2017-06-28 8:34 ` Ralf Baechle [this message]
2017-06-28 11:23 ` Maciej W. Rozycki
2017-06-19 15:50 ` [PATCH 4/8] MIPS: unaligned: Add DSP lwx & lhx missaligned access support Aleksandar Markovic
2017-06-19 15:50 ` [PATCH 5/8] MIPS: math-emu: Handle zero accumulator case in MADDF and MSUBF separately Aleksandar Markovic
2017-06-19 15:50 ` [PATCH 6/8] input: goldfish: Fix multitouch event handling Aleksandar Markovic
2017-06-19 15:50 ` [PATCH 7/8] tty: goldfish: Use streaming DMA for r/w operations on Ranchu platforms Aleksandar Markovic
2017-06-19 15:50 ` [PATCH 8/8] tty: goldfish: Implement support for kernel 'earlycon' parameter Aleksandar Markovic
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