kernel_samsung_sm7125

jenna

Commit Graph

Author	SHA1	Message	Date
Andi Kleen	312df5f1a1	[PATCH] x86_64: Add pmtimer support There are unfortunately more and more multi processor Opteron systems which don't have HPET timer support in the southbridge. This covers in particular Nvidia and VIA chipsets. They also don't guarantee that the TSCs are synchronized between CPUs; and especially with MP powernow the systems are nearly unusable because the time gets very inconsistent between CPUs. The timer code for x86-64 was originally written under the assumption that we could fall back to the HPET timer on such systems. But this doesn't work there. Another alternative is to use the ACPI PM timer as primary time source. This patch does that. The kernel only uses PM timer when there is no other choice because it has some disadvantages. Ported over from i386. It should be faster than the i386 version because I dropped the "read three times" workaround, but is still considerable slower than HPET and also does not work together with vsyscalls which have to be disabled. Cc: <mark.langsdorf@amd.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>	20 years ago
Linus Torvalds	1da177e4c3	Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!	20 years ago

Author

SHA1

Message

Date

Andi Kleen

312df5f1a1

[PATCH] x86_64: Add pmtimer support

There are unfortunately more and more multi processor Opteron systems which
don't have HPET timer support in the southbridge.  This covers in particular
Nvidia and VIA chipsets.  They also don't guarantee that the TSCs are
synchronized between CPUs; and especially with MP powernow the systems are
nearly unusable because the time gets very inconsistent between CPUs.

The timer code for x86-64 was originally written under the assumption that we
could fall back to the HPET timer on such systems.  But this doesn't work
there.

Another alternative is to use the ACPI PM timer as primary time source.  This
patch does that.  The kernel only uses PM timer when there is no other choice
because it has some disadvantages.

Ported over from i386.  It should be faster than the i386 version because I
dropped the "read three times" workaround, but is still considerable slower
than HPET and also does not work together with vsyscalls which have to be
disabled.

Cc: <mark.langsdorf@amd.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

20 years ago

Linus Torvalds

1da177e4c3

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

20 years ago

2 Commits (87bec66b9691522414862dd8d41e430b063735ef)