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2015-04-14x86: expose number of page table levels on Kconfig levelKirill A. Shutemov1-4/+4
We would want to use number of page table level to define mm_struct. Let's expose it as CONFIG_PGTABLE_LEVELS. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-19x86: pte_protnone() and pmd_protnone() must check entry is not presentDavid Vrabel1-2/+4
Since _PAGE_PROTNONE aliases _PAGE_GLOBAL it is only valid if _PAGE_PRESENT is clear. Make pte_protnone() and pmd_protnone() check for this. This fixes a 64-bit Xen PV guest regression introduced by 8a0516ed8b90 ("mm: convert p[te|md]_numa users to p[te|md]_protnone_numa"). Any userspace process would endlessly fault. In a 64-bit PV guest, userspace page table entries have _PAGE_GLOBAL set by the hypervisor. This meant that any fault on a present userspace entry (e.g., a write to a read-only mapping) would be misinterpreted as a NUMA hinting fault and the fault would not be correctly handled, resulting in the access endlessly faulting. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12x86: mm: restore original pte_special checkMel Gorman1-7/+1
Commit b38af4721f59 ("x86,mm: fix pte_special versus pte_numa") adjusted the pte_special check to take into account that a special pte had SPECIAL and neither PRESENT nor PROTNONE. Now that NUMA hinting PTEs are no longer modifying _PAGE_PRESENT it should be safe to restore the original pte_special behaviour. Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dave Jones <davej@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Rik van Riel <riel@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12mm: remove remaining references to NUMA hinting bits and helpersMel Gorman1-19/+3
This patch removes the NUMA PTE bits and associated helpers. As a side-effect it increases the maximum possible swap space on x86-64. One potential source of problems is races between the marking of PTEs PROT_NONE, NUMA hinting faults and migration. It must be guaranteed that a PTE being protected is not faulted in parallel, seen as a pte_none and corrupting memory. The base case is safe but transhuge has problems in the past due to an different migration mechanism and a dependance on page lock to serialise migrations and warrants a closer look. task_work hinting update parallel fault ------------------------ -------------- change_pmd_range change_huge_pmd __pmd_trans_huge_lock pmdp_get_and_clear __handle_mm_fault pmd_none do_huge_pmd_anonymous_page read? pmd_lock blocks until hinting complete, fail !pmd_none test write? __do_huge_pmd_anonymous_page acquires pmd_lock, checks pmd_none pmd_modify set_pmd_at task_work hinting update parallel migration ------------------------ ------------------ change_pmd_range change_huge_pmd __pmd_trans_huge_lock pmdp_get_and_clear __handle_mm_fault do_huge_pmd_numa_page migrate_misplaced_transhuge_page pmd_lock waits for updates to complete, recheck pmd_same pmd_modify set_pmd_at Both of those are safe and the case where a transhuge page is inserted during a protection update is unchanged. The case where two processes try migrating at the same time is unchanged by this series so should still be ok. I could not find a case where we are accidentally depending on the PTE not being cleared and flushed. If one is missed, it'll manifest as corruption problems that start triggering shortly after this series is merged and only happen when NUMA balancing is enabled. Signed-off-by: Mel Gorman <mgorman@suse.de> Tested-by: Sasha Levin <sasha.levin@oracle.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dave Jones <davej@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Rik van Riel <riel@redhat.com> Cc: Mark Brown <broonie@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12mm: add p[te|md] protnone helpers for use by NUMA balancingMel Gorman1-0/+16
This is a preparatory patch that introduces protnone helpers for automatic NUMA balancing. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dave Jones <davej@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-10x86: drop _PAGE_FILE and pte_file()-related helpersKirill A. Shutemov1-20/+0
We've replaced remap_file_pages(2) implementation with emulation. Nobody creates non-linear mapping anymore. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10Merge branch 'akpm' (patchbomb from Andrew)Linus Torvalds1-0/+5
Merge first patchbomb from Andrew Morton: - a few minor cifs fixes - dma-debug upadtes - ocfs2 - slab - about half of MM - procfs - kernel/exit.c - panic.c tweaks - printk upates - lib/ updates - checkpatch updates - fs/binfmt updates - the drivers/rtc tree - nilfs - kmod fixes - more kernel/exit.c - various other misc tweaks and fixes * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits) exit: pidns: fix/update the comments in zap_pid_ns_processes() exit: pidns: alloc_pid() leaks pid_namespace if child_reaper is exiting exit: exit_notify: re-use "dead" list to autoreap current exit: reparent: call forget_original_parent() under tasklist_lock exit: reparent: avoid find_new_reaper() if no children exit: reparent: introduce find_alive_thread() exit: reparent: introduce find_child_reaper() exit: reparent: document the ->has_child_subreaper checks exit: reparent: s/while_each_thread/for_each_thread/ in find_new_reaper() exit: reparent: fix the cross-namespace PR_SET_CHILD_SUBREAPER reparenting exit: reparent: fix the dead-parent PR_SET_CHILD_SUBREAPER reparenting exit: proc: don't try to flush /proc/tgid/task/tgid exit: release_task: fix the comment about group leader accounting exit: wait: drop tasklist_lock before psig->c* accounting exit: wait: don't use zombie->real_parent exit: wait: cleanup the ptrace_reparented() checks usermodehelper: kill the kmod_thread_locker logic usermodehelper: don't use CLONE_VFORK for ____call_usermodehelper() fs/hfs/catalog.c: fix comparison bug in hfs_cat_keycmp nilfs2: fix the nilfs_iget() vs. nilfs_new_inode() races ...
2014-12-10mm: fix huge zero page accounting in smaps reportKirill A. Shutemov1-0/+5
As a small zero page, huge zero page should not be accounted in smaps report as normal page. For small pages we rely on vm_normal_page() to filter out zero page, but vm_normal_page() is not designed to handle pmds. We only get here due hackish cast pmd to pte in smaps_pte_range() -- pte and pmd format is not necessary compatible on each and every architecture. Let's add separate codepath to handle pmds. follow_trans_huge_pmd() will detect huge zero page for us. We would need pmd_dirty() helper to do this properly. The patch adds it to THP-enabled architectures which don't yet have one. [akpm@linux-foundation.org: use do_div to fix 32-bit build] Signed-off-by: "Kirill A. Shutemov" <kirill@shutemov.name> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Tested-by: Fengwei Yin <yfw.kernel@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-11-16x86: Use new cache mode type in asm/pgtable.hJuergen Gross1-9/+10
Instead of directly using the cache mode bits in the pte switch to using the cache mode type. This requires changing some callers of is_new_memtype_allowed() to be changed as well. Based-on-patch-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: stefan.bader@canonical.com Cc: xen-devel@lists.xensource.com Cc: konrad.wilk@oracle.com Cc: ville.syrjala@linux.intel.com Cc: david.vrabel@citrix.com Cc: jbeulich@suse.com Cc: toshi.kani@hp.com Cc: plagnioj@jcrosoft.com Cc: tomi.valkeinen@ti.com Cc: bhelgaas@google.com Link: http://lkml.kernel.org/r/1415019724-4317-8-git-send-email-jgross@suse.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-08-29x86,mm: fix pte_special versus pte_numaHugh Dickins1-2/+7
Sasha Levin has shown oopses on ffffea0003480048 and ffffea0003480008 at mm/memory.c:1132, running Trinity on different 3.16-rc-next kernels: where zap_pte_range() checks page->mapping to see if PageAnon(page). Those addresses fit struct pages for pfns d2001 and d2000, and in each dump a register or a stack slot showed d2001730 or d2000730: pte flags 0x730 are PCD ACCESSED PROTNONE SPECIAL IOMAP; and Sasha's e820 map has a hole between cfffffff and 100000000, which would need special access. Commit c46a7c817e66 ("x86: define _PAGE_NUMA by reusing software bits on the PMD and PTE levels") has broken vm_normal_page(): a PROTNONE SPECIAL pte no longer passes the pte_special() test, so zap_pte_range() goes on to try to access a non-existent struct page. Fix this by refining pte_special() (SPECIAL with PRESENT or PROTNONE) to complement pte_numa() (SPECIAL with neither PRESENT nor PROTNONE). A hint that this was a problem was that c46a7c817e66 added pte_numa() test to vm_normal_page(), and moved its is_zero_pfn() test from slow to fast path: This was papering over a pte_special() snag when the zero page was encountered during zap. This patch reverts vm_normal_page() to how it was before, relying on pte_special(). It still appears that this patch may be incomplete: aren't there other places which need to be handling PROTNONE along with PRESENT? For example, pte_mknuma() clears _PAGE_PRESENT and sets _PAGE_NUMA, but on a PROT_NONE area, that would make it pte_special(). This is side-stepped by the fact that NUMA hinting faults skipped PROT_NONE VMAs and there are no grounds where a NUMA hinting fault on a PROT_NONE VMA would be interesting. Fixes: c46a7c817e66 ("x86: define _PAGE_NUMA by reusing software bits on the PMD and PTE levels") Reported-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: <stable@vger.kernel.org> [3.16] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04mm: x86 pgtable: require X86_64 for soft-dirty trackerCyrill Gorcunov1-0/+5
Tracking dirty status on 2 level pages requires very ugly macros and taking into account how old the machines who can operate without PAE mode only are, lets drop soft dirty tracker from them for code simplicity (note I can't drop all the macros from 2 level pages by now since _PAGE_BIT_PROTNONE and _PAGE_BIT_FILE are still used even without tracker). Linus proposed to completely rip off softdirty support on x86-32 (even with PAE) and since for CRIU we're not planning to support native x86-32 mode, lets do that. (Softdirty tracker is relatively new feature which is mostly used by CRIU so I don't expect if such API change would cause problems for userspace). Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Steven Noonan <steven@uplinklabs.net> Cc: Rik van Riel <riel@redhat.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04x86: define _PAGE_NUMA by reusing software bits on the PMD and PTE levelsMel Gorman1-4/+11
_PAGE_NUMA is currently an alias of _PROT_PROTNONE to trap NUMA hinting faults on x86. Care is taken such that _PAGE_NUMA is used only in situations where the VMA flags distinguish between NUMA hinting faults and prot_none faults. This decision was x86-specific and conceptually it is difficult requiring special casing to distinguish between PROTNONE and NUMA ptes based on context. Fundamentally, we only need the _PAGE_NUMA bit to tell the difference between an entry that is really unmapped and a page that is protected for NUMA hinting faults as if the PTE is not present then a fault will be trapped. Swap PTEs on x86-64 use the bits after _PAGE_GLOBAL for the offset. This patch shrinks the maximum possible swap size and uses the bit to uniquely distinguish between NUMA hinting ptes and swap ptes. Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Anvin <hpa@zytor.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Steven Noonan <steven@uplinklabs.net> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-03-31Merge branch 'x86-efi-for-linus' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 EFI changes from Ingo Molnar: "The main changes: - Add debug code to the dump EFI pagetable - Borislav Petkov - Make 1:1 runtime mapping robust when booting on machines with lots of memory - Borislav Petkov - Move the EFI facilities bits out of 'x86_efi_facility' and into efi.flags which is the standard architecture independent place to keep EFI state, by Matt Fleming. - Add 'EFI mixed mode' support: this allows 64-bit kernels to be booted from 32-bit firmware. This needs a bootloader that supports the 'EFI handover protocol'. By Matt Fleming" * 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits) x86, efi: Abstract x86 efi_early calls x86/efi: Restore 'attr' argument to query_variable_info() x86/efi: Rip out phys_efi_get_time() x86/efi: Preserve segment registers in mixed mode x86/boot: Fix non-EFI build x86, tools: Fix up compiler warnings x86/efi: Re-disable interrupts after calling firmware services x86/boot: Don't overwrite cr4 when enabling PAE x86/efi: Wire up CONFIG_EFI_MIXED x86/efi: Add mixed runtime services support x86/efi: Firmware agnostic handover entry points x86/efi: Split the boot stub into 32/64 code paths x86/efi: Add early thunk code to go from 64-bit to 32-bit x86/efi: Build our own EFI services pointer table efi: Add separate 32-bit/64-bit definitions x86/efi: Delete dead code when checking for non-native x86/mm/pageattr: Always dump the right page table in an oops x86, tools: Consolidate #ifdef code x86/boot: Cleanup header.S by removing some #ifdefs efi: Use NULL instead of 0 for pointer ...
2014-03-25Revert "xen: properly account for _PAGE_NUMA during xen pte translations"David Vrabel1-12/+2
This reverts commit a9c8e4beeeb64c22b84c803747487857fe424b68. PTEs in Xen PV guests must contain machine addresses if _PAGE_PRESENT is set and pseudo-physical addresses is _PAGE_PRESENT is clear. This is because during a domain save/restore (migration) the page table entries are "canonicalised" and uncanonicalised". i.e., MFNs are converted to PFNs during domain save so that on a restore the page table entries may be rewritten with the new MFNs on the destination. This canonicalisation is only done for PTEs that are present. This change resulted in writing PTEs with MFNs if _PAGE_PROTNONE (or _PAGE_NUMA) was set but _PAGE_PRESENT was clear. These PTEs would be migrated as-is which would result in unexpected behaviour in the destination domain. Either a) the MFN would be translated to the wrong PFN/page; b) setting the _PAGE_PRESENT bit would clear the PTE because the MFN is no longer owned by the domain; or c) the present bit would not get set. Symptoms include "Bad page" reports when munmapping after migrating a domain. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: <stable@vger.kernel.org> [3.12+]
2014-03-04x86, ptdump: Add the functionality to dump an arbitrary pagetableBorislav Petkov1-1/+2
With reusing the ->trampoline_pgd page table for mapping EFI regions in order to use them after having switched to EFI virtual mode, it is very useful to be able to dump aforementioned page table in dmesg. This adds that functionality through the walk_pgd_level() interface which can be called from somewhere else. The original functionality of dumping to debugfs remains untouched. Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-02-10xen: properly account for _PAGE_NUMA during xen pte translationsMel Gorman1-2/+12
Steven Noonan forwarded a users report where they had a problem starting vsftpd on a Xen paravirtualized guest, with this in dmesg: BUG: Bad page map in process vsftpd pte:8000000493b88165 pmd:e9cc01067 page:ffffea00124ee200 count:0 mapcount:-1 mapping: (null) index:0x0 page flags: 0x2ffc0000000014(referenced|dirty) addr:00007f97eea74000 vm_flags:00100071 anon_vma:ffff880e98f80380 mapping: (null) index:7f97eea74 CPU: 4 PID: 587 Comm: vsftpd Not tainted 3.12.7-1-ec2 #1 Call Trace: dump_stack+0x45/0x56 print_bad_pte+0x22e/0x250 unmap_single_vma+0x583/0x890 unmap_vmas+0x65/0x90 exit_mmap+0xc5/0x170 mmput+0x65/0x100 do_exit+0x393/0x9e0 do_group_exit+0xcc/0x140 SyS_exit_group+0x14/0x20 system_call_fastpath+0x1a/0x1f Disabling lock debugging due to kernel taint BUG: Bad rss-counter state mm:ffff880e9ca60580 idx:0 val:-1 BUG: Bad rss-counter state mm:ffff880e9ca60580 idx:1 val:1 The issue could not be reproduced under an HVM instance with the same kernel, so it appears to be exclusive to paravirtual Xen guests. He bisected the problem to commit 1667918b6483 ("mm: numa: clear numa hinting information on mprotect") that was also included in 3.12-stable. The problem was related to how xen translates ptes because it was not accounting for the _PAGE_NUMA bit. This patch splits pte_present to add a pteval_present helper for use by xen so both bare metal and xen use the same code when checking if a PTE is present. [mgorman@suse.de: wrote changelog, proposed minor modifications] [akpm@linux-foundation.org: fix typo in comment] Reported-by: Steven Noonan <steven@uplinklabs.net> Tested-by: Steven Noonan <steven@uplinklabs.net> Signed-off-by: Elena Ufimtseva <ufimtseva@gmail.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: <stable@vger.kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-18mm: fix TLB flush race between migration, and change_protection_rangeRik van Riel1-2/+9
There are a few subtle races, between change_protection_range (used by mprotect and change_prot_numa) on one side, and NUMA page migration and compaction on the other side. The basic race is that there is a time window between when the PTE gets made non-present (PROT_NONE or NUMA), and the TLB is flushed. During that time, a CPU may continue writing to the page. This is fine most of the time, however compaction or the NUMA migration code may come in, and migrate the page away. When that happens, the CPU may continue writing, through the cached translation, to what is no longer the current memory location of the process. This only affects x86, which has a somewhat optimistic pte_accessible. All other architectures appear to be safe, and will either always flush, or flush whenever there is a valid mapping, even with no permissions (SPARC). The basic race looks like this: CPU A CPU B CPU C load TLB entry make entry PTE/PMD_NUMA fault on entry read/write old page start migrating page change PTE/PMD to new page read/write old page [*] flush TLB reload TLB from new entry read/write new page lose data [*] the old page may belong to a new user at this point! The obvious fix is to flush remote TLB entries, by making sure that pte_accessible aware of the fact that PROT_NONE and PROT_NUMA memory may still be accessible if there is a TLB flush pending for the mm. This should fix both NUMA migration and compaction. [mgorman@suse.de: fix build] Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Alex Thorlton <athorlton@sgi.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: make sure _PAGE_SWP_SOFT_DIRTY bit is not set on present pteCyrill Gorcunov1-15/+19
_PAGE_SOFT_DIRTY bit should never be set on present pte so add VM_BUG_ON to catch any potential future abuse. Also add a comment on _PAGE_SWP_SOFT_DIRTY definition explaining scope of its usage. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Pavel Emelyanov <xemul@parallels.com> Acked-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-04Merge branch 'x86-asmlinkage-for-linus' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/asmlinkage changes from Ingo Molnar: "As a preparation for Andi Kleen's LTO patchset (link time optimizations using GCC's -flto which build time optimization has steadily increased in quality over the past few years and might eventually be usable for the kernel too) this tree includes a handful of preparatory patches that make function calling convention annotations consistent again: - Mark every function without arguments (or 64bit only) that is used by assembly code with asmlinkage() - Mark every function with parameters or variables that is used by assembly code as __visible. For the vanilla kernel this has documentation, consistency and debuggability advantages, for the time being" * 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/asmlinkage: Fix warning in xen asmlinkage change x86, asmlinkage, vdso: Mark vdso variables __visible x86, asmlinkage, power: Make various symbols used by the suspend asm code visible x86, asmlinkage: Make dump_stack visible x86, asmlinkage: Make 64bit checksum functions visible x86, asmlinkage, paravirt: Add __visible/asmlinkage to xen paravirt ops x86, asmlinkage, apm: Make APM data structure used from assembler visible x86, asmlinkage: Make syscall tables visible x86, asmlinkage: Make several variables used from assembler/linker script visible x86, asmlinkage: Make kprobes code visible and fix assembler code x86, asmlinkage: Make various syscalls asmlinkage x86, asmlinkage: Make 32bit/64bit __switch_to visible x86, asmlinkage: Make _*_start_kernel visible x86, asmlinkage: Make all interrupt handlers asmlinkage / __visible x86, asmlinkage: Change dotraplinkage into __visible on 32bit x86: Fix sys_call_table type in asm/syscall.h
2013-08-13mm: save soft-dirty bits on file pagesCyrill Gorcunov1-0/+15
Andy reported that if file page get reclaimed we lose the soft-dirty bit if it was there, so save _PAGE_BIT_SOFT_DIRTY bit when page address get encoded into pte entry. Thus when #pf happens on such non-present pte we can restore it back. Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-13mm: save soft-dirty bits on swapped pagesCyrill Gorcunov1-0/+15
Andy Lutomirski reported that if a page with _PAGE_SOFT_DIRTY bit set get swapped out, the bit is getting lost and no longer available when pte read back. To resolve this we introduce _PTE_SWP_SOFT_DIRTY bit which is saved in pte entry for the page being swapped out. When such page is to be read back from a swap cache we check for bit presence and if it's there we clear it and restore the former _PAGE_SOFT_DIRTY bit back. One of the problem was to find a place in pte entry where we can save the _PTE_SWP_SOFT_DIRTY bit while page is in swap. The _PAGE_PSE was chosen for that, it doesn't intersect with swap entry format stored in pte. Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-06x86, asmlinkage: Make several variables used from assembler/linker script ↵Andi Kleen1-1/+2
visible Plus one function, load_gs_index(). Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1375740170-7446-10-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-07-03mm: soft-dirty bits for user memory changes trackingPavel Emelyanov1-2/+22
The soft-dirty is a bit on a PTE which helps to track which pages a task writes to. In order to do this tracking one should 1. Clear soft-dirty bits from PTEs ("echo 4 > /proc/PID/clear_refs) 2. Wait some time. 3. Read soft-dirty bits (55'th in /proc/PID/pagemap2 entries) To do this tracking, the writable bit is cleared from PTEs when the soft-dirty bit is. Thus, after this, when the task tries to modify a page at some virtual address the #PF occurs and the kernel sets the soft-dirty bit on the respective PTE. Note, that although all the task's address space is marked as r/o after the soft-dirty bits clear, the #PF-s that occur after that are processed fast. This is so, since the pages are still mapped to physical memory, and thus all the kernel does is finds this fact out and puts back writable, dirty and soft-dirty bits on the PTE. Another thing to note, is that when mremap moves PTEs they are marked with soft-dirty as well, since from the user perspective mremap modifies the virtual memory at mremap's new address. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-06-29consolidate io_remap_pfn_range definitionsAl Viro1-3/+0
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-21Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds1-0/+17
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm changes from Peter Anvin: "This is a huge set of several partly interrelated (and concurrently developed) changes, which is why the branch history is messier than one would like. The *really* big items are two humonguous patchsets mostly developed by Yinghai Lu at my request, which completely revamps the way we create initial page tables. In particular, rather than estimating how much memory we will need for page tables and then build them into that memory -- a calculation that has shown to be incredibly fragile -- we now build them (on 64 bits) with the aid of a "pseudo-linear mode" -- a #PF handler which creates temporary page tables on demand. This has several advantages: 1. It makes it much easier to support things that need access to data very early (a followon patchset uses this to load microcode way early in the kernel startup). 2. It allows the kernel and all the kernel data objects to be invoked from above the 4 GB limit. This allows kdump to work on very large systems. 3. It greatly reduces the difference between Xen and native (Xen's equivalent of the #PF handler are the temporary page tables created by the domain builder), eliminating a bunch of fragile hooks. The patch series also gets us a bit closer to W^X. Additional work in this pull is the 64-bit get_user() work which you were also involved with, and a bunch of cleanups/speedups to __phys_addr()/__pa()." * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (105 commits) x86, mm: Move reserving low memory later in initialization x86, doc: Clarify the use of asm("%edx") in uaccess.h x86, mm: Redesign get_user with a __builtin_choose_expr hack x86: Be consistent with data size in getuser.S x86, mm: Use a bitfield to mask nuisance get_user() warnings x86/kvm: Fix compile warning in kvm_register_steal_time() x86-32: Add support for 64bit get_user() x86-32, mm: Remove reference to alloc_remap() x86-32, mm: Remove reference to resume_map_numa_kva() x86-32, mm: Rip out x86_32 NUMA remapping code x86/numa: Use __pa_nodebug() instead x86: Don't panic if can not alloc buffer for swiotlb mm: Add alloc_bootmem_low_pages_nopanic() x86, 64bit, mm: hibernate use generic mapping_init x86, 64bit, mm: Mark data/bss/brk to nx x86: Merge early kernel reserve for 32bit and 64bit x86: Add Crash kernel low reservation x86, kdump: Remove crashkernel range find limit for 64bit memblock: Add memblock_mem_size() x86, boot: Not need to check setup_header version for setup_data ...
2013-02-19Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds1-0/+12
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/asm changes from Ingo Molnar: "The biggest change (by line count) is the unification of the XOR code and then the introduction of an additional SSE based XOR assembly method. The other bigger change is the head_32.S rework/cleanup by Borislav Petkov. Last but not least there's the usual laundry list of small but dangerous (and hopefully perfectly tested) changes to subtle low level x86 code, plus cleanups." * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, head_32: Give the 6 label a real name x86, head_32: Remove second CPUID detection from default_entry x86: Detect CPUID support early at boot x86, head_32: Remove i386 pieces x86: Require MOVBE feature in cpuid when we use it x86: Enable ARCH_USE_BUILTIN_BSWAP x86/xor: Add alternative SSE implementation only prefetching once per 64-byte line x86/xor: Unify SSE-base xor-block routines x86: Fix a typo x86/mm: Fix the argument passed to sync_global_pgds() x86/mm: Convert update_mmu_cache() and update_mmu_cache_pmd() to functions ix86: Tighten asmlinkage_protect() constraints
2013-02-13x86/mm: Check if PUD is large when validating a kernel addressMel Gorman1-0/+5
A user reported the following oops when a backup process reads /proc/kcore: BUG: unable to handle kernel paging request at ffffbb00ff33b000 IP: [<ffffffff8103157e>] kern_addr_valid+0xbe/0x110 [...] Call Trace: [<ffffffff811b8aaa>] read_kcore+0x17a/0x370 [<ffffffff811ad847>] proc_reg_read+0x77/0xc0 [<ffffffff81151687>] vfs_read+0xc7/0x130 [<ffffffff811517f3>] sys_read+0x53/0xa0 [<ffffffff81449692>] system_call_fastpath+0x16/0x1b Investigation determined that the bug triggered when reading system RAM at the 4G mark. On this system, that was the first address using 1G pages for the virt->phys direct mapping so the PUD is pointing to a physical address, not a PMD page. The problem is that the page table walker in kern_addr_valid() is not checking pud_large() and treats the physical address as if it was a PMD. If it happens to look like pmd_none then it'll silently fail, probably returning zeros instead of real data. If the data happens to look like a present PMD though, it will be walked resulting in the oops above. This patch adds the necessary pud_large() check. Unfortunately the problem was not readily reproducible and now they are running the backup program without accessing /proc/kcore so the patch has not been validated but I think it makes sense. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.coM> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: stable@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20130211145236.GX21389@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-02-01Merge remote-tracking branch 'origin/x86/mm' into x86/mm2H. Peter Anvin1-0/+14
Explicitly merging these two branches due to nontrivial conflicts and to allow further work. Resolved Conflicts: arch/x86/kernel/head32.c arch/x86/kernel/head64.c arch/x86/mm/init_64.c arch/x86/realmode/init.c Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-01-29Merge remote-tracking branch 'origin/x86/boot' into x86/mm2H. Peter Anvin1-2/+15
Coming patches to x86/mm2 require the changes and advanced baseline in x86/boot. Resolved Conflicts: arch/x86/kernel/setup.c mm/nobootmem.c Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-01-25x86, mm: Pagetable level size/shift/mask helpersDave Hansen1-0/+14
I plan to use lookup_address() to walk the kernel pagetables in a later patch. It returns a "pte" and the level in the pagetables where the "pte" was found. The level is just an enum and needs to be converted to a useful value in order to do address calculations with it. These helpers will be used in at least two places. This also gives the anonymous enum a real name so that no one gets confused about what they should be passing in to these helpers. "PTE_SHIFT" was chosen for naming consistency with the other pagetable levels (PGD/PUD/PMD_SHIFT). Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20130122212431.405D3A8C@kernel.stglabs.ibm.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-01-24x86/mm: Convert update_mmu_cache() and update_mmu_cache_pmd() to functionsKirill A. Shutemov1-0/+12
Converting macros to functions unhide type problems before changes will be integrated and trigger problems on other architectures. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-12-11mm: numa: pte_numa() and pmd_numa()Andrea Arcangeli1-2/+9
Implement pte_numa and pmd_numa. We must atomically set the numa bit and clear the present bit to define a pte_numa or pmd_numa. Once a pte or pmd has been set as pte_numa or pmd_numa, the next time a thread touches a virtual address in the corresponding virtual range, a NUMA hinting page fault will trigger. The NUMA hinting page fault will clear the NUMA bit and set the present bit again to resolve the page fault. The expectation is that a NUMA hinting page fault is used as part of a placement policy that decides if a page should remain on the current node or migrated to a different node. Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Mel Gorman <mgorman@suse.de>
2012-12-11x86/mm: Introduce pte_accessible()Rik van Riel1-0/+6
We need pte_present to return true for _PAGE_PROTNONE pages, to indicate that the pte is associated with a page. However, for TLB flushing purposes, we would like to know whether the pte points to an actually accessible page. This allows us to skip remote TLB flushes for pages that are not actually accessible. Fill in this method for x86 and provide a safe (but slower) method on other architectures. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Fixed-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-66p11te4uj23gevgh4j987ip@git.kernel.org [ Added Linus's review fixes. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-11-17x86, mm: setup page table in top-downYinghai Lu1-0/+1
Get pgt_buf early from BRK, and use it to map PMD_SIZE from top at first. Then use mapped pages to map more ranges below, and keep looping until all pages get mapped. alloc_low_page will use page from BRK at first, after that buffer is used up, will use memblock to find and reserve pages for page table usage. Introduce min_pfn_mapped to make sure find new pages from mapped ranges, that will be updated when lower pages get mapped. Also add step_size to make sure that don't try to map too big range with limited mapped pages initially, and increase the step_size when we have more mapped pages on hand. We don't need to call pagetable_reserve anymore, reserve work is done in alloc_low_page() directly. At last we can get rid of calculation and find early pgt related code. -v2: update to after fix_xen change, also use MACRO for initial pgt_buf size and add comments with it. -v3: skip big reserved range in memblock.reserved near end. -v4: don't need fix_xen change now. -v5: add changelog about moving about reserving pagetable to alloc_low_page. Suggested-by: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-22-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: Move init_memory_mapping calling out of setup.cYinghai Lu1-1/+1
Now init_memory_mapping is called two times, later will be called for every ram ranges. Could put all related init_mem calling together and out of setup.c. Actually, it reverts commit 1bbbbe7 x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct mapping. will address that later with complete solution include handling hole under 4g. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-5-git-send-email-yinghai@kernel.org Reviewed-by: Pekka Enberg <penberg@kernel.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-17x86, mm: Add global page_size_mask and probe one time onlyYinghai Lu1-0/+1
Now we pass around use_gbpages and use_pse for calculating page table size, Later we will need to call init_memory_mapping for every ram range one by one, that mean those calculation will be done several times. Those information are the same for all ram range and could be stored in page_size_mask and could be probed it one time only. Move that probing code out of init_memory_mapping into separated function probe_page_size_mask(), and call it before all init_memory_mapping. Suggested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-2-git-send-email-yinghai@kernel.org Reviewed-by: Pekka Enberg <penberg@kernel.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-10-09mm: thp: fix pmd_present for split_huge_page and PROT_NONE with THPAndrea Arcangeli1-3/+8
In many places !pmd_present has been converted to pmd_none. For pmds that's equivalent and pmd_none is quicker so using pmd_none is better. However (unless we delete pmd_present) we should provide an accurate pmd_present too. This will avoid the risk of code thinking the pmd is non present because it's under __split_huge_page_map, see the pmd_mknotpresent there and the comment above it. If the page has been mprotected as PROT_NONE, it would also lead to a pmd_present false negative in the same way as the race with split_huge_page. Because the PSE bit stays on at all times (both during split_huge_page and when the _PAGE_PROTNONE bit get set), we could only check for the PSE bit, but checking the PROTNONE bit too is still good to remember pmd_present must always keep PROT_NONE into account. This explains a not reproducible BUG_ON that was seldom reported on the lists. The same issue is in pmd_large, it would go wrong with both PROT_NONE and if it races with split_huge_page. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-02UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel ↵David Howells1-2/+2
system headers Convert #include "..." to #include <path/...> in kernel system headers. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>
2011-12-18x86: Use "do { } while(0)" for empty flush_tlb_fix_spurious_fault() macroJesper Juhl1-1/+1
If one builds the kernel with -Wempty-body one gets this warning: mm/memory.c:3432:46: warning: suggest braces around empty body in an ¡if¢ statement [-Wempty-body] due to the fact that 'flush_tlb_fix_spurious_fault' is a macro that can sometimes be defined to nothing. Signed-off-by: Jesper Juhl <jj@chaosbits.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: linux-mm@kvack.org Cc: Michel Lespinasse <walken@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Johannes Weiner <hannes@cmpxchg.org> Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1112180128070.21784@swampdragon.chaosbits.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-13thp: don't allow transparent hugepage support without PSEAndrea Arcangeli1-0/+5
Archs implementing Transparent Hugepage Support must implement a function called has_transparent_hugepage to be sure the virtual or physical CPU supports Transparent Hugepages. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13thp: add pmd_modifyJohannes Weiner1-0/+10
Add pmd_modify() for use with mprotect() on huge pmds. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13thp: add x86 32bit supportJohannes Weiner1-0/+117
Add support for transparent hugepages to x86 32bit. Share the same VM_ bitflag for VM_MAPPED_COPY. mm/nommu.c will never support transparent hugepages. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13thp: add pmd mangling functions to x86Andrea Arcangeli1-1/+1
Add needed pmd mangling functions with symmetry with their pte counterparts. pmdp_splitting_flush() is the only new addition on the pmd_ methods and it's needed to serialize the VM against split_huge_page. It simply atomically sets the splitting bit in a similar way pmdp_clear_flush_young atomically clears the accessed bit. pmdp_splitting_flush() also has to flush the tlb to make it effective against gup_fast, but it wouldn't really require to flush the tlb too. Just the tlb flush is the simplest operation we can invoke to serialize pmdp_splitting_flush() against gup_fast. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13thp: no paravirt version of pmd opsAndrea Arcangeli1-0/+3
No paravirt version of set_pmd_at/pmd_update/pmd_update_defer. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13thp: add native_set_pmd_atAndrea Arcangeli1-0/+6
Used by paravirt and not paravirt set_pmd_at. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-19x86, mm: Hold mm->page_table_lock while doing vmalloc_syncJeremy Fitzhardinge1-0/+2
Take mm->page_table_lock while syncing the vmalloc region. This prevents a race with the Xen pagetable pin/unpin code, which expects that the page_table_lock is already held. If this race occurs, then Xen can see an inconsistent page type (a page can either be read/write or a pagetable page, and pin/unpin converts it between them), which will cause either the pin or the set_p[gm]d to fail; either will crash the kernel. vmalloc_sync_all() should be called rarely, so this extra use of page_table_lock should not interfere with its normal users. The mm pointer is stashed in the pgd page's index field, as that won't be otherwise used for pgds. Reported-by: Ian Campbell <ian.cambell@eu.citrix.com> Originally-by: Jan Beulich <jbeulich@novell.com> LKML-Reference: <4CB88A4C.1080305@goop.org> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-08-23x86, mm: Avoid unnecessary TLB flushShaohua Li1-0/+2
In x86, access and dirty bits are set automatically by CPU when CPU accesses memory. When we go into the code path of below flush_tlb_fix_spurious_fault(), we already set dirty bit for pte and don't need flush tlb. This might mean tlb entry in some CPUs hasn't dirty bit set, but this doesn't matter. When the CPUs do page write, they will automatically check the bit and no software involved. On the other hand, flush tlb in below position is harmful. Test creates CPU number of threads, each thread writes to a same but random address in same vma range and we measure the total time. Under a 4 socket system, original time is 1.96s, while with the patch, the time is 0.8s. Under a 2 socket system, there is 20% time cut too. perf shows a lot of time are taking to send ipi/handle ipi for tlb flush. Signed-off-by: Shaohua Li <shaohua.li@intel.com> LKML-Reference: <20100816011655.GA362@sli10-desk.sh.intel.com> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Andrea Archangeli <aarcange@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-11-23x86, mm: is_untracked_pat_range() takes a normal semiclosed rangeH. Peter Anvin1-1/+1
is_untracked_pat_range() -- like its components, is_ISA_range() and is_GRU_range(), takes a normal semiclosed interval (>=, <) whereas the PAT code called it as if it took a closed range (>=, <=). Fix. Although this is a bug, I believe it is non-manifest, simply because none of the callers will call this with non-page-aligned addresses. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> LKML-Reference: <20091119202341.GA4420@sgi.com>
2009-11-23x86, mm: Call is_untracked_pat_range() rather than is_ISA_range()H. Peter Anvin1-2/+4
Checkin fd12a0d69aee6d90fa9b9890db24368a897f8423 made the PAT untracked range a platform configurable, but missed on occurrence of is_ISA_range() which still refers to PAT-untracked memory, and therefore should be using the configurable. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Jack Steiner <steiner@sgi.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> LKML-Reference: <20091119202341.GA4420@sgi.com>
2009-09-18Merge branch 'x86-platform-for-linus' of ↵Linus Torvalds1-10/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (38 commits) x86: Move get/set_wallclock to x86_platform_ops x86: platform: Fix section annotations x86: apic namespace cleanup x86: Distangle ioapic and i8259 x86: Add Moorestown early detection x86: Add hardware_subarch ID for Moorestown x86: Add early platform detection x86: Move tsc_init to late_time_init x86: Move tsc_calibration to x86_init_ops x86: Replace the now identical time_32/64.c by time.c x86: time_32/64.c unify profile_pc x86: Move calibrate_cpu to tsc.c x86: Make timer setup and global variables the same in time_32/64.c x86: Remove mca bus ifdef from timer interrupt x86: Simplify timer_ack magic in time_32.c x86: Prepare unification of time_32/64.c x86: Remove do_timer hook x86: Add timer_init to x86_init_ops x86: Move percpu clockevents setup to x86_init_ops x86: Move xen_post_allocator_init into xen_pagetable_setup_done ... Fix up conflicts in arch/x86/include/asm/io_apic.h