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  1. 02 Aug, 2005 35 commits
  3. 01 Aug, 2005 5 commits
    • Linus Torvalds's avatar
      Revert ACPI interrupt resume changes · 697a2d63
      Linus Torvalds authored 
      If there are devices that use interrupts over a suspend event, ACPI must
restore the PCI interrupt links on resume.  Anything else breaks any
device that hasn't been converted to the new (dubious) PM rules.

Drivers that need the irq free/re-aquire sequence can be done one by one
independently of this one.
      697a2d63
    • Linus Torvalds's avatar
      Fix get_user_pages() race for write access · 4ceb5db9
      Linus Torvalds authored 
      There's no real guarantee that handle_mm_fault() will always be able to
break a COW situation - if an update from another thread ends up
modifying the page table some way, handle_mm_fault() may end up
requiring us to re-try the operation.

That's normally fine, but get_user_pages() ended up re-trying it as a
read, and thus a write access could in theory end up losing the dirty
bit or be done on a page that had not been properly COW'ed.

This makes get_user_pages() always retry write accesses as write
accesses by making "follow_page()" require that a writable follow has
the dirty bit set.  That simplifies the code and solves the race: if the
COW break fails for some reason, we'll just loop around and try again.
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      4ceb5db9
    • Antonino A. Daplas's avatar
      [PATCH] tridentfb: Fix scrolling artifacts during disk IO · 8d894c47
      Antonino A. Daplas authored 
      Reported by: Jochen Hein (Bugzilla Bug 4312)

When there is disk I/O happening, the framebuffer has a little snow on
the screen.  Once I/O has finished, no garbage remains on screen.

This bug was explained by: Knut Petersen

Most important is CRTC register 2f, signal quality is also improved for
higher vclk values by changing set_vclk() according to the X drivers and
cyblafb.c

The fix is to set the performance register (0x2f) with a more stable
value.
Signed-off-by: default avatarAntonino Daplas <adaplas@pol.net>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      8d894c47
    • Antonino A. Daplas's avatar
      [PATCH] tridentfb: Fix scrolling artifacts if acceleration is enabled · 8dad46cf
      Antonino A. Daplas authored 
      Reported by: Jochen Hein (Bugzilla Bug 4386)

booting leaves the end of long lines in the last line on screen when
scrolling.  When X is running, scrolling puts garbage on the screen
(looks like X data) Console switch fixes the screen.  Behaviour seems to
be identical with noaccel and without on the video=tridentfb parameter
in lilo.conf.

This bug was explained by: Knut_Petersen

Acceleration is broken for all BLADE 3D chips for all versions of kernel
2.6 except for 32bit modes.  Most important reason is that the u32 col
parameter of the graphics engine needs the color value replicated to all
u8 of the u32 (8bit modes) and to both u16 of the u32.

Fix color value passed to graphics engine, verified by the reporter.
Signed-off-by: default avatarAntonino Daplas <adaplas@pol.net>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      8dad46cf
    • Ingo Molnar's avatar
      [PATCH] remove sys_set_zone_reclaim() · 6cb54819
      Ingo Molnar authored 
      This removes sys_set_zone_reclaim() for now.  While i'm sure Martin is
trying to solve a real problem, we must not hard-code an incomplete and
insufficient approach into a syscall, because syscalls are pretty much
for eternity.  I am quite strongly convinced that this syscall must not
hit v2.6.13 in its current form.

Firstly, the syscall lacks basic syscall design: e.g. it allows the
global setting of VM policy for unprivileged users. (!) [ Imagine an
Oracle installation and a SAP installation on the same NUMA box fighting
over the 'optimal' setting for this flag. What will they do? Will they
try to set the flag to their own preferred value every second or so? ]

Secondly, it was added based on a single datapoint from Martin:

 http://marc.theaimsgroup.com/?l=linux-mm&m=111763597218177&w=2

where Martin characterizes the numbers the following way:

 ' Run-to-run variability for "make -j" is huge, so these numbers aren't
   terribly useful except to see that with reclaim the benchmark still
   finishes in a reasonable amount of time. '

in other words: the fundamental problem has likely not been solved, only
a tendential move into the right direction has been observed, and a
handful of numbers were picked out of a set of hugely variable results,
without showing the variability data. How much variance is there
run-to-run?

I'd really suggest to first walk the walk and see what's needed to get
stable & predictable kernel compilation numbers on that NUMA box, before
adding random syscalls to tune a particular aspect of the VM ... which
approach might not even matter once the whole picture has been analyzed
and understood!

The third, most important point is that the syscall exposes VM tuning
internals in a completely unstructured way. What sense does it make to
have a _GLOBAL_ per-node setting for 'should we go to another node for
reclaim'? If then it might make sense to do this per-app, via numalib or
so.

The change is minimalistic in that it doesnt remove the syscall and the
underlying infrastructure changes, only the user-visible changes.  We
could perhaps add a CAP_SYS_ADMIN-only sysctl for this hack, a'ka
/proc/sys/vm/swappiness, but even that looks quite counterproductive
when the generic approach is that we are trying to reduce the number of
external factors in the VM balance picture.
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      6cb54819
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