search for: pte_modify

...s a new transaction-like abstraction for doing RMW updates to a pte, hooks it into paravirt_ops, and then makes use of it in Xen. The basic problem is that mprotect is very slow under Xen (up to 50x slower than native), primarily because of the ptent = ptep_get_and_clear(mm, addr, pte); ptent = pte_modify(ptent, newprot); /* ... */ set_pte_at(mm, addr, pte, ptent); sequence in mm/mprotect.c:change_pte_range(). This is bad for Xen for two reasons: 1: ptep_get_and_clear() ends up being a xchg on the pte. Since the pte page is read-only (as it must be, because Xen needs to control all...

...s a new transaction-like abstraction for doing RMW updates to a pte, hooks it into paravirt_ops, and then makes use of it in Xen. The basic problem is that mprotect is very slow under Xen (up to 50x slower than native), primarily because of the ptent = ptep_get_and_clear(mm, addr, pte); ptent = pte_modify(ptent, newprot); /* ... */ set_pte_at(mm, addr, pte, ptent); sequence in mm/mprotect.c:change_pte_range(). This is bad for Xen for two reasons: 1: ptep_get_and_clear() ends up being a xchg on the pte. Since the pte page is read-only (as it must be, because Xen needs to control all...

...s a new transaction-like abstraction for doing RMW updates to a pte, hooks it into paravirt_ops, and then makes use of it in Xen. The basic problem is that mprotect is very slow under Xen (up to 50x slower than native), primarily because of the ptent = ptep_get_and_clear(mm, addr, pte); ptent = pte_modify(ptent, newprot); /* ... */ set_pte_at(mm, addr, pte, ptent); sequence in mm/mprotect.c:change_pte_range(). This is bad for Xen for two reasons: 1: ptep_get_and_clear() ends up being a xchg on the pte. Since the pte page is read-only (as it must be, because Xen needs to control all...

Hey folks, This is the part-of-pvops-implementation-that-is-not-exactly-a-merge. Neat, uh? This is the majority of the work. The first patch in the series does not really belong here. It was already sent to lkml separetedly before, but I'm including it again, for a very simple reason: Try to test the paravirt patches without it, and you'll fail miserably ;-) (and it was not yet

Hey folks, This is the part-of-pvops-implementation-that-is-not-exactly-a-merge. Neat, uh? This is the majority of the work. The first patch in the series does not really belong here. It was already sent to lkml separetedly before, but I'm including it again, for a very simple reason: Try to test the paravirt patches without it, and you'll fail miserably ;-) (and it was not yet

...s a new transaction-like abstraction for doing RMW updates to a pte, hooks it into paravirt_ops, and then makes use of it in Xen. The basic problem is that mprotect is very slow under Xen (up to 50x slower than native), primarily because of the ptent = ptep_get_and_clear(mm, addr, pte); ptent = pte_modify(ptent, newprot); /* ... */ set_pte_at(mm, addr, pte, ptent); sequence in mm/mprotect.c:change_pte_range(). This is bad for Xen for two reasons: 1: ptep_get_and_clear() ends up being a xchg on the pte. Since the pte page is read-only (as it must be, because Xen needs to control all...

...s a new transaction-like abstraction for doing RMW updates to a pte, hooks it into paravirt_ops, and then makes use of it in Xen. The basic problem is that mprotect is very slow under Xen (up to 50x slower than native), primarily because of the ptent = ptep_get_and_clear(mm, addr, pte); ptent = pte_modify(ptent, newprot); /* ... */ set_pte_at(mm, addr, pte, ptent); sequence in mm/mprotect.c:change_pte_range(). This is bad for Xen for two reasons: 1: ptep_get_and_clear() ends up being a xchg on the pte. Since the pte page is read-only (as it must be, because Xen needs to control all...

...s a new transaction-like abstraction for doing RMW updates to a pte, hooks it into paravirt_ops, and then makes use of it in Xen. The basic problem is that mprotect is very slow under Xen (up to 50x slower than native), primarily because of the ptent = ptep_get_and_clear(mm, addr, pte); ptent = pte_modify(ptent, newprot); /* ... */ set_pte_at(mm, addr, pte, ptent); sequence in mm/mprotect.c:change_pte_range(). This is bad for Xen for two reasons: 1: ptep_get_and_clear() ends up being a xchg on the pte. Since the pte page is read-only (as it must be, because Xen needs to control all...

...t) { - pte_t pte; - pte_val(pte) = physpage | pgprot_val(pgprot); - pte_val(pte) &= __supported_pte_mask; - return pte; + unsigned long pte; + pte = physpage | pgprot_val(pgprot); + pte &= __supported_pte_mask; + return __pte(pte); } /* Change flags of a PTE */ -static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) +static inline pte_t pte_modify(pte_t pte_old, pgprot_t newprot) { - pte_val(pte) &= _PAGE_CHG_MASK; - pte_val(pte) |= pgprot_val(newprot); - pte_val(pte) &= __supported_pte_mask; - return pte; + unsigned long pte = pte_val(pte_old); + pte &= _PAGE_...

...t) { - pte_t pte; - pte_val(pte) = physpage | pgprot_val(pgprot); - pte_val(pte) &= __supported_pte_mask; - return pte; + unsigned long pte; + pte = physpage | pgprot_val(pgprot); + pte &= __supported_pte_mask; + return __pte(pte); } /* Change flags of a PTE */ -static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) +static inline pte_t pte_modify(pte_t pte_old, pgprot_t newprot) { - pte_val(pte) &= _PAGE_CHG_MASK; - pte_val(pte) |= pgprot_val(newprot); - pte_val(pte) &= __supported_pte_mask; - return pte; + unsigned long pte = pte_val(pte_old); + pte &= _PAGE_...

...nclude/asm-i386/pgtable.h =================================================================== --- linux-2.6.13.orig/include/asm-i386/pgtable.h 2005-08-24 09:43:27.000000000 -0700 +++ linux-2.6.13/include/asm-i386/pgtable.h 2005-08-24 09:47:38.000000000 -0700 @@ -388,6 +388,28 @@ static inline pte_t pte_modify(pte_t pte extern pte_t *lookup_address(unsigned long address); /* + * Helper function that returns physical page for virtual address. + * This assumes the mapping is valid. + */ +#define virt_to_pfn(_address) \ +({ \ + unsigned long long __paddr; \ + pgd_t *pgd = pgd_offset_k(_a...

..._lock(mm, pmd, addr, &ptl); do { if (pte_present(*pte)) { - u[i].ptr = virt_to_machine(pte) | MMU_PT_UPDATE_PRESERVE_AD; + u[i].ptr = (__pmd_val(*pmd) & PHYSICAL_PAGE_MASK) + | ((unsigned long)pte & ~PAGE_MASK) + | MMU_PT_UPDATE_PRESERVE_AD; u[i].val = __pte_val(pte_modify(*pte, newprot)); if (++i == MAX_BATCHED_FULL_PTES) { if ((rc = HYPERVISOR_mmu_update( _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel

...nclude/asm-i386/pgtable.h =================================================================== --- linux-2.6.13.orig/include/asm-i386/pgtable.h 2005-08-24 09:43:27.000000000 -0700 +++ linux-2.6.13/include/asm-i386/pgtable.h 2005-08-24 09:47:38.000000000 -0700 @@ -388,6 +388,28 @@ static inline pte_t pte_modify(pte_t pte extern pte_t *lookup_address(unsigned long address); /* + * Helper function that returns physical page for virtual address. + * This assumes the mapping is valid. + */ +#define virt_to_pfn(_address) \ +({ \ + unsigned long long __paddr; \ + pgd_t *pgd = pgd_offset_k(_a...

Here is an slightly updated version of the paravirt_ops patch. If your comments and criticism were welcome before, now it's even more! There are some issues that are _not_ addressed in this revision, and here are the causes: * split debugreg into multiple functions, suggested by Andi: - Me and jsfg agree that introducing more pvops (specially 14!) is not worthwhile. So, although we do

Here is an slightly updated version of the paravirt_ops patch. If your comments and criticism were welcome before, now it's even more! There are some issues that are _not_ addressed in this revision, and here are the causes: * split debugreg into multiple functions, suggested by Andi: - Me and jsfg agree that introducing more pvops (specially 14!) is not worthwhile. So, although we do

Hey folks, Here's a new spin of the pvops64 patch series. We didn't get that many comments from the last time, so it should be probably almost ready to get in. Heya! >From the last version, the most notable changes are: * consolidation of system.h, merging jeremy's comments about ordering concerns * consolidation of smp functions that goes through smp_ops. They're sharing

Hey folks, Here's a new spin of the pvops64 patch series. We didn't get that many comments from the last time, so it should be probably almost ready to get in. Heya! >From the last version, the most notable changes are: * consolidation of system.h, merging jeremy's comments about ordering concerns * consolidation of smp functions that goes through smp_ops. They're sharing

This is hopefully the last iteration of the pvops64 patch. >From the last version, we have only one change, which is include/asm-x86_64/processor.h: There were still one survivor in raw asm. Also, git screwed me up for some reason, and the 25th patch was missing the new files, paravirt.{c,h}. (although I do remember having git-add'ed it, but who knows...) Andrew, could you please push it

This is hopefully the last iteration of the pvops64 patch. >From the last version, we have only one change, which is include/asm-x86_64/processor.h: There were still one survivor in raw asm. Also, git screwed me up for some reason, and the 25th patch was missing the new files, paravirt.{c,h}. (although I do remember having git-add'ed it, but who knows...) Andrew, could you please push it

Hi, 2.6.29-rc3 x86_64 guest on x86_64 RHEL5.3 host: https://bugzilla.redhat.com/484295 kernel BUG at mm/filemap.c:123! invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC last sysfs file: /sys/devices/vbd-51712/block/xvda/xvda2/dev CPU 0 Modules linked in: ipv6 xts lrw gf128mul sha256_generic cbc dm_crypt