17 Oct
2015
17 Oct
'15
2:05 a.m.
Yeah, I was reading my mail backwards. This is better now, still needs the
IPI fix.
Best regards,
Alex Ionescu
On Fri, Oct 16, 2015 at 6:44 AM, Alexander Andrejevic <
theflash(a)sdf.lonestar.org> wrote:
If I recall correctly, one of the commits that
followed this one also added
ValidKernelPteLocal and ValidKernelPdeLocal, which are used for PTEs/PDEs
that shouldn't be global.
Regards,
Alex
On Thu, Oct 15, 2015 at 06:55:51PM -0700, Alex Ionescu wrote:
This is wrong, wrong, wrong.
1) The feature needs to be enabled on all processors, not just one.
There's
a reason for that loop.
2) ValidKernelPte/Pde being marked global will make ALL kernel pages
global. This is probably not what you want.
Best regards,
Alex Ionescu
On Wed, Oct 14, 2015 at 12:33 PM, <sginsberg(a)svn.reactos.org> wrote:
> Author: sginsberg
> Date: Wed Oct 14 19:33:35 2015
> New Revision: 69528
>
> URL: http://svn.reactos.org/svn/reactos?rev=69528&view=rev
> Log:
> [NTOS]
> Add super-complicated handling of global pages to KeFlushCurrentTb
(pretty
> much the same code which has been in
HalpFlushTLB for the past ~6
years).
> This should be all that is required to make
this feature work
(everything
> else being in place already), and *seems* to
work fine but is disabled
> under a switch until tested thoroughly.
>
> Global pages, an important optimization that allows for not flushing
the
> whole x86 TLB every time CR3 is changed
(typically on context switch
to a
> new process, or during process
attach/detach), relies on us doing extra
> work whenever we do alter a global page. This is likely where any bugs
will
> have to be flushed out!
>
> Fixup Ki386EnableGlobalPage while we are at it -- disable/restore
> interrupts properly, and verify PGE-bit isn't set (nothing should have
> touched it before this routine, which is responsible for initializing
it,
> so we shouldn't have to disable it).
Fix, but disable, the CPU-sync
spin as
> well as there should be no particular reason
to do this for
PGE-enabling
> during initialization (no other processor
will be messing with PTEs at
this
> stage, as compared to a call to
KeFlushEntireTb).
>
> Everyone, repeat after me: Global pages are awesome!
>
> Modified:
> trunk/reactos/ntoskrnl/include/ntoskrnl.h
> trunk/reactos/ntoskrnl/ke/i386/cpu.c
> trunk/reactos/ntoskrnl/ke/i386/patpge.c
> trunk/reactos/ntoskrnl/mm/ARM3/i386/init.c
>
> Modified: trunk/reactos/ntoskrnl/include/ntoskrnl.h
> URL:
>
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/include/ntoskrnl.…
>
>
==============================================================================
> ---
trunk/reactos/ntoskrnl/include/ntoskrnl.h [iso-8859-1] (original)
> +++ trunk/reactos/ntoskrnl/include/ntoskrnl.h [iso-8859-1] Wed Oct 14
> 19:33:35 2015
> @@ -98,6 +98,14 @@
> #define ASSERT NT_ASSERT
> #endif
>
> +
> +//
> +// Switch for enabling global page support
> +//
> +
> +//#define _GLOBAL_PAGES_ARE_AWESOME_
> +
> +
> /* Internal Headers */
> #include "internal/ntoskrnl.h"
> #include "config.h"
>
> Modified: trunk/reactos/ntoskrnl/ke/i386/cpu.c
> URL:
>
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ke/i386/cpu.c?rev…
>
>
==============================================================================
> --- trunk/reactos/ntoskrnl/ke/i386/cpu.c
[iso-8859-1] (original)
> +++ trunk/reactos/ntoskrnl/ke/i386/cpu.c [iso-8859-1] Wed Oct 14
> 19:33:35 2015
> @@ -878,8 +878,37 @@
> NTAPI
> KeFlushCurrentTb(VOID)
> {
> +
> +#if !defined(_GLOBAL_PAGES_ARE_AWESOME_)
> +
> /* Flush the TLB by resetting CR3 */
> __writecr3(__readcr3());
> +
> +#else
> +
> + /* Check if global pages are enabled */
> + if (KeFeatureBits & KF_GLOBAL_PAGE)
> + {
> + ULONG Cr4;
> +
> + /* Disable PGE */
> + Cr4 = __readcr4() & ~CR4_PGE;
> + __writecr4(Cr4);
> +
> + /* Flush everything */
> + __writecr3(__readcr3());
> +
> + /* Re-enable PGE */
> + __writecr4(Cr4 | CR4_PGE);
> + }
> + else
> + {
> + /* No global pages, resetting CR3 is enough */
> + __writecr3(__readcr3());
> + }
> +
> +#endif
> +
> }
>
> VOID
>
> Modified: trunk/reactos/ntoskrnl/ke/i386/patpge.c
> URL:
>
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ke/i386/patpge.c?…
>
>
==============================================================================
> > --- trunk/reactos/ntoskrnl/ke/i386/patpge.c [iso-8859-1] (original)
> > +++ trunk/reactos/ntoskrnl/ke/i386/patpge.c [iso-8859-1] Wed Oct 14
> > 19:33:35 2015
> > @@ -17,40 +17,41 @@
> >
> > /* FUNCTIONS
> > *****************************************************************/
> >
> > +INIT_SECTION
> > ULONG_PTR
> > NTAPI
> > -INIT_FUNCTION
> > Ki386EnableGlobalPage(IN ULONG_PTR Context)
> > {
> > - PLONG Count = (PLONG)Context;
> > - ULONG Cr4, Cr3;
> > + //PLONG Count;
> > +#if defined(_GLOBAL_PAGES_ARE_AWESOME_)
> > + ULONG Cr4;
> > +#endif
> > + BOOLEAN Enable;
> >
> > /* Disable interrupts */
> > - _disable();
> > -
> > - /* Decrease CPU Count and loop until it's reached 0 */
> > - do {InterlockedDecrement(Count);} while (!*Count);
> > -
> > - /* Now check if this is the Boot CPU */
> > - if (!KeGetPcr()->Number)
> > - {
> > - /* It is.FIXME: Patch KeFlushCurrentTb */
> > - }
> > -
> > - /* Now get CR4 and make sure PGE is masked out */
> > + Enable = KeDisableInterrupts();
> > +
> > + /* Spin until other processors are ready */
> > + //Count = (PLONG)Context;
> > + //InterlockedDecrement(Count);
> > + //while (*Count) YieldProcessor();
> > +
> > +#if defined(_GLOBAL_PAGES_ARE_AWESOME_)
> > +
> > + /* Get CR4 and ensure global pages are disabled */
> > Cr4 = __readcr4();
> > - __writecr4(Cr4 & ~CR4_PGE);
> > -
> > - /* Flush the TLB */
> > - Cr3 = __readcr3();
> > - __writecr3(Cr3);
> > + ASSERT(!(Cr4 & CR4_PGE));
> > +
> > + /* Reset CR3 to flush the TLB */
> > + __writecr3(__readcr3());
> >
> > /* Now enable PGE */
> > - DPRINT("Global page support detected but not yet taken advantage
> > of\n");
> > - //__writecr4(Cr4 | CR4_PGE);
> > -
> > - /* Restore interrupts */
> > - _enable();
> > + __writecr4(Cr4 | CR4_PGE);
> > +
> > +#endif
> > +
> > + /* Restore interrupts and return */
> > + KeRestoreInterrupts(Enable);
> > return 0;
> > }
>
>
> > Modified: trunk/reactos/ntoskrnl/mm/ARM3/i386/init.c
> > URL:
> >
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/ARM3/i386/init…
>
>
==============================================================================
> > --- trunk/reactos/ntoskrnl/mm/ARM3/i386/init.c [iso-8859-1] (original)
> > +++ trunk/reactos/ntoskrnl/mm/ARM3/i386/init.c [iso-8859-1] Wed Oct 14
> > 19:33:35 2015
> > @@ -249,15 +249,18 @@
> > PMMPFN Pfn1;
> > ULONG Flags;
> >
> > +#if defined(_GLOBAL_PAGES_ARE_AWESOME_)
> > +
> > /* Check for global bit */
> > -#if 0
> > if (KeFeatureBits & KF_GLOBAL_PAGE)
> > {
> > /* Set it on the template PTE and PDE */
> > ValidKernelPte.u.Hard.Global = TRUE;
> > ValidKernelPde.u.Hard.Global = TRUE;
> > }
> > +
> > #endif
> > +
> > /* Now templates are ready */
> > TempPte = ValidKernelPte;
> > TempPde = ValidKernelPde;
>
>
> >
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--
Alexander Andrejevic <theflash(a)sdf.lonestar.org>
SDF Public Access UNIX System - http://sdf.lonestar.org
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