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From: Jan Beulich <jbeulich@suse.com>
To: "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
Cc: "Andrew Cooper" <andrew.cooper3@citrix.com>,
	"Wei Liu" <wl@xen.org>, "Roger Pau Monné" <roger.pau@citrix.com>
Subject: [PATCH 0/7] x86: memcpy() / memset() (non-)ERMS flavors plus fallout
Date: Tue, 27 Apr 2021 14:51:59 +0200	[thread overview]
Message-ID: <6d6da76c-ccc8-afa2-bd06-5ae132c354f2@suse.com> (raw)

While the performance varies quite a bit on older (pre-ERMS) and
newer (ERMS) hardware, so far we've been going with just a single
flavor of these two functions, and oddly enough with ones not
consistent with one another. Using plain memcpy() / memset() on
MMIO (video frame buffer) is generally okay, but the ERMS variant
of memcpy() turned out to regress (boot) performance in a way
easily visible to the human eye. Hence as a prerequisite step
this series switches the frame buffer (and VGA) mapping to be
write-combining independent of firmware arrangements (of MTRRs
in particular).

1: x86: correct comment about alternatives ordering
2: x86: introduce ioremap_wc()
3: x86: re-work memset()
4: x86: re-work memcpy()
5: video/vesa: unmap frame buffer when relinquishing console
6: video/vesa: drop "vesa-mtrr" command line option
7: video/vesa: adjust (not just) command line option handling

Side note: While strictly speaking the xen/drivers/video/ changes
fall under REST maintainership, with that code getting built for
x86 only I'm restricting Cc-s to x86 maintainers.

Jan


             reply	other threads:[~2021-04-27 12:52 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-27 12:51 Jan Beulich [this message]
2021-04-27 12:53 ` [PATCH 1/7] x86: correct comment about alternatives ordering Jan Beulich
2021-04-27 13:19   ` Andrew Cooper
2021-04-27 12:54 ` [PATCH 2/7] x86: introduce ioremap_wc() Jan Beulich
2021-04-27 17:13   ` Andrew Cooper
2021-04-28  9:41     ` Jan Beulich
2021-04-27 12:54 ` [PATCH 3/7] x86: re-work memset() Jan Beulich
2021-04-27 12:54 ` [PATCH 4/7] x86: re-work memcpy() Jan Beulich
2021-04-27 12:55 ` [PATCH 5/7] video/vesa: unmap frame buffer when relinquishing console Jan Beulich
2021-04-27 12:56 ` [PATCH 6/7] video/vesa: drop "vesa-mtrr" command line option Jan Beulich
2021-04-27 13:20   ` Andrew Cooper
2021-04-27 12:56 ` [PATCH 7/7] video/vesa: adjust (not just) command line option handling Jan Beulich
2021-04-27 13:49   ` Andrew Cooper
2021-04-27 14:04     ` Jan Beulich
2021-05-27 11:47       ` Jan Beulich

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