similar to: [PATCH 2/4] Pte clear optimization.patch

Add comment and condense code to make use of native_local_ptep_get_and_clear function. Also, it turns out the 2-level and 3-level paging definitions were identical, so move the common definition into pgtable.h Signed-off-by: Zachary Amsden <zach@vmware.com> diff -r b3bbc1b5e085 include/asm-i386/pgtable-2level.h --- a/include/asm-i386/pgtable-2level.h Wed Apr 11 18:23:44 2007 -0700 +++

Add comment and condense code to make use of native_local_ptep_get_and_clear function. Also, it turns out the 2-level and 3-level paging definitions were identical, so move the common definition into pgtable.h Signed-off-by: Zachary Amsden <zach@vmware.com> diff -r b3bbc1b5e085 include/asm-i386/pgtable-2level.h --- a/include/asm-i386/pgtable-2level.h Wed Apr 11 18:23:44 2007 -0700 +++

In situations where page table updates need only be made locally, and there is no cross-processor A/D bit races involved, we need not use the heavyweight xchg instruction to atomically fetch and clear page table entries. Instead, we can just read and clear them directly. This introduces a neat optimization for non-SMP kernels; drop the atomic xchg operations from page table updates. Thanks to

In situations where page table updates need only be made locally, and there is no cross-processor A/D bit races involved, we need not use the heavyweight xchg instruction to atomically fetch and clear page table entries. Instead, we can just read and clear them directly. This introduces a neat optimization for non-SMP kernels; drop the atomic xchg operations from page table updates. Thanks to

diff -r f1dd818c2f06 include/asm-i386/pgtable-2level.h --- a/include/asm-i386/pgtable-2level.h Thu Oct 19 03:03:09 2006 -0700 +++ b/include/asm-i386/pgtable-2level.h Thu Oct 19 03:03:18 2006 -0700 @@ -22,8 +22,7 @@ #define pte_clear(mm,addr,xp) do { set_pte_at(mm, addr, xp, __pte(0)); } while (0) #define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0) -#define

diff -r f1dd818c2f06 include/asm-i386/pgtable-2level.h --- a/include/asm-i386/pgtable-2level.h Thu Oct 19 03:03:09 2006 -0700 +++ b/include/asm-i386/pgtable-2level.h Thu Oct 19 03:03:18 2006 -0700 @@ -22,8 +22,7 @@ #define pte_clear(mm,addr,xp) do { set_pte_at(mm, addr, xp, __pte(0)); } while (0) #define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0) -#define

plain text document attachment (xx-paravirt-core.patch) Paravirt Ops core files. Signed-off-by: Steven Rostedt srostedt@redhat.com Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Index: clean-start/arch/x86_64/kernel/paravirt.c =================================================================== --- /dev/null +++ clean-start/arch/x86_64/kernel/paravirt.c @@ -0,0 +1,504 @@ +/*

plain text document attachment (xx-paravirt-core.patch) Paravirt Ops core files. Signed-off-by: Steven Rostedt srostedt@redhat.com Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Index: clean-start/arch/x86_64/kernel/paravirt.c =================================================================== --- /dev/null +++ clean-start/arch/x86_64/kernel/paravirt.c @@ -0,0 +1,504 @@ +/*

Change pte_clear_full to a more appropriately named pte_clear_not_present, allowing optimizations when not-present mapping changes need not be reflected in the hardware TLB for protected page table modes. There is also another case that can use it in the fremap code. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> ---

With removal of lguest some of the paravirt functions are no longer needed. Remove them. Signed-off-by: Juergen Gross <jgross at suse.com> --- arch/x86/include/asm/desc.h | 3 +-- arch/x86/include/asm/paravirt.h | 37 ----------------------------------- arch/x86/include/asm/paravirt_types.h | 9 --------- arch/x86/include/asm/pgtable.h | 27

With removal of lguest some of the paravirt functions are no longer needed. Remove them. Signed-off-by: Juergen Gross <jgross at suse.com> --- arch/x86/include/asm/desc.h | 3 +-- arch/x86/include/asm/paravirt.h | 37 ----------------------------------- arch/x86/include/asm/paravirt_types.h | 9 --------- arch/x86/include/asm/pgtable.h | 27

The last 32-bit user of stuff under CONFIG_PARAVIRT_XXL is gone. Remove 32-bit specific parts. Signed-off-by: Juergen Gross <jgross at suse.com> --- arch/x86/entry/vdso/vdso32/vclock_gettime.c | 1 + arch/x86/include/asm/paravirt.h | 92 +++------------------ arch/x86/include/asm/paravirt_types.h | 21 ----- arch/x86/include/asm/pgtable-3level_types.h | 5 --

The last 32-bit user of stuff under CONFIG_PARAVIRT_XXL is gone. Remove 32-bit specific parts. Signed-off-by: Juergen Gross <jgross at suse.com> --- arch/x86/entry/vdso/vdso32/vclock_gettime.c | 1 + arch/x86/include/asm/paravirt.h | 120 ++------------------ arch/x86/include/asm/paravirt_types.h | 21 ---- arch/x86/include/asm/pgtable-3level_types.h | 5 -

Hi all, I've been working on a port of paravirt_ops for the x86_64 architectures for a couple of days. Here's the result so far. I'm posting it soon for early cooments. The more, the better. It's obviously based on the previous work for i386, with the needed modifications. By now, I'm able to boot a bare metal kernel, but there are still some known issues, that are in my TODO

Hi all, I've been working on a port of paravirt_ops for the x86_64 architectures for a couple of days. Here's the result so far. I'm posting it soon for early cooments. The more, the better. It's obviously based on the previous work for i386, with the needed modifications. By now, I'm able to boot a bare metal kernel, but there are still some known issues, that are in my TODO

The ptep_establish macro is only used on user-level PTEs, for P->P mapping changes. Since these always happen under protection of the pagetable lock, the strong synchronization of a 64-bit cmpxchg is not needed, in fact, not even a lock prefix needs to be used. We can simply instead clear the P-bit, followed by a normal set. The write ordering is still important to avoid the possibility of

In shadow mode hypervisors, ptep_get_and_clear achieves the desired purpose of keeping the shadows in sync by issuing a native_get_and_clear, followed by a call to pte_update, which indicates the PTE has been modified. Direct mode hypervisors (Xen) have no need for this anyway, and will trap the update using writable pagetables. This means no hypervisor makes use of ptep_get_and_clear; there is

In shadow mode hypervisors, ptep_get_and_clear achieves the desired purpose of keeping the shadows in sync by issuing a native_get_and_clear, followed by a call to pte_update, which indicates the PTE has been modified. Direct mode hypervisors (Xen) have no need for this anyway, and will trap the update using writable pagetables. This means no hypervisor makes use of ptep_get_and_clear; there is

MMU code movement. Unfortunately, this one is a little bit more complicated than the rest. We have to override the default accessors that directly write to page table entries. Because of the 2/3-level PAE split in Linux, this turned out to be really ugly at first, but by allowing the sub-arch layer to override the definitions and keeping the native definitions in place, the code becomes much

MMU code movement. Unfortunately, this one is a little bit more complicated than the rest. We have to override the default accessors that directly write to page table entries. Because of the 2/3-level PAE split in Linux, this turned out to be really ugly at first, but by allowing the sub-arch layer to override the definitions and keeping the native definitions in place, the code becomes much