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2008-07-19highmem: Export totalhigh_pages.David S. Miller
Hash et al. sizing code in SCTP wants to make the calculation totalram_pages - totalhigh_pages, just like TCP. But this requires an export for the CONFIG_HIGHMEM case to work. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-16Merge commit 'origin/master'Benjamin Herrenschmidt
Manual merge of: arch/powerpc/Kconfig arch/powerpc/kernel/stacktrace.c arch/powerpc/mm/slice.c arch/ppc/kernel/smp.c
2008-07-15Merge branch 'generic-ipi' into generic-ipi-for-linusIngo Molnar
Conflicts: arch/powerpc/Kconfig arch/s390/kernel/time.c arch/x86/kernel/apic_32.c arch/x86/kernel/cpu/perfctr-watchdog.c arch/x86/kernel/i8259_64.c arch/x86/kernel/ldt.c arch/x86/kernel/nmi_64.c arch/x86/kernel/smpboot.c arch/x86/xen/smp.c include/asm-x86/hw_irq_32.h include/asm-x86/hw_irq_64.h include/asm-x86/mach-default/irq_vectors.h include/asm-x86/mach-voyager/irq_vectors.h include/asm-x86/smp.h kernel/Makefile Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-15Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6: slab: rename slab_destroy_objs slub: current is always valid slub: Add check for kfree() of non slab objects.
2008-07-15slab: rename slab_destroy_objsRabin Vincent
With the removal of destructors, slab_destroy_objs no longer actually destroys any objects, making the kernel doc incorrect and the function name misleading. In keeping with the other debug functions, rename it to slab_destroy_debugcheck and drop the kernel doc. Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-07-15slub: current is always validAlexey Dobriyan
Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-07-15slub: Add check for kfree() of non slab objects.Christoph Lameter
We can detect kfree()s on non slab objects by checking for PageCompound(). Works in the same way as for ksize. This helped me catch an invalid kfree(). Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-07-15Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (61 commits) ext4: Documention update for new ordered mode and delayed allocation ext4: do not set extents feature from the kernel ext4: Don't allow nonextenst mount option for large filesystem ext4: Enable delalloc by default. ext4: delayed allocation i_blocks fix for stat ext4: fix delalloc i_disksize early update issue ext4: Handle page without buffers in ext4_*_writepage() ext4: Add ordered mode support for delalloc ext4: Invert lock ordering of page_lock and transaction start in delalloc mm: Add range_cont mode for writeback ext4: delayed allocation ENOSPC handling percpu_counter: new function percpu_counter_sum_and_set ext4: Add delayed allocation support in data=writeback mode vfs: add hooks for ext4's delayed allocation support jbd2: Remove data=ordered mode support using jbd buffer heads ext4: Use new framework for data=ordered mode in JBD2 jbd2: Implement data=ordered mode handling via inodes vfs: export filemap_fdatawrite_range() ext4: Fix lock inversion in ext4_ext_truncate() ext4: Invert the locking order of page_lock and transaction start ...
2008-07-15Merge commit '85082fd7cbe3173198aac0eb5e85ab1edcc6352c' into test-buildBenjamin Herrenschmidt
Manual fixup of: arch/powerpc/Kconfig
2008-07-14Merge branch 'tracing/for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (228 commits) ftrace: build fix for ftraced_suspend ftrace: separate out the function enabled variable ftrace: add ftrace_kill_atomic ftrace: use current CPU for function startup ftrace: start wakeup tracing after setting function tracer ftrace: check proper config for preempt type ftrace: trace schedule ftrace: define function trace nop ftrace: move sched_switch enable after markers ftrace: prevent ftrace modifications while being kprobe'd, v2 fix "ftrace: store mcount address in rec->ip" mmiotrace broken in linux-next (8-bit writes only) ftrace: avoid modifying kprobe'd records ftrace: freeze kprobe'd records kprobes: enable clean usage of get_kprobe ftrace: store mcount address in rec->ip ftrace: build fix with gcc 4.3 namespacecheck: fixes ftrace: fix "notrace" filtering priority ftrace: fix printout ...
2008-07-14Merge branch 'x86/for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (821 commits) x86: make 64bit hpet_set_mapping to use ioremap too, v2 x86: get x86_phys_bits early x86: max_low_pfn_mapped fix #4 x86: change _node_to_cpumask_ptr to return const ptr x86: I/O APIC: remove an IRQ2-mask hack x86: fix numaq_tsc_disable calling x86, e820: remove end_user_pfn x86: max_low_pfn_mapped fix, #3 x86: max_low_pfn_mapped fix, #2 x86: max_low_pfn_mapped fix, #1 x86_64: fix delayed signals x86: remove conflicting nx6325 and nx6125 quirks x86: Recover timer_ack lost in the merge of the NMI watchdog x86: I/O APIC: Never configure IRQ2 x86: L-APIC: Always fully configure IRQ0 x86: L-APIC: Set IRQ0 as edge-triggered x86: merge dwarf2 headers x86: use AS_CFI instead of UNWIND_INFO x86: use ignore macro instead of hash comment x86: use matching CFI_ENDPROC ...
2008-07-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6: (31 commits) avr32: Fix typo of IFSR in a comment in the PIO header file avr32: Power Management support ("standby" and "mem" modes) avr32: Add system device for the internal interrupt controller (intc) avr32: Add simple SRAM allocator avr32: Enable SDRAMC clock at startup rtc-at32ap700x: Enable wakeup macb: Basic suspend/resume support atmel_serial: Drain console TX shifter before suspending atmel_serial: Fix build on avr32 with CONFIG_PM enabled avr32: Use a quicklist for PTE allocation as well avr32: Use a quicklist for PGD allocation avr32: Cover the kernel page tables in the user PGDs avr32: Store virtual addresses in the PGD avr32: Remove useless zeroing of swapper_pg_dir at startup avr32: Clean up and optimize the TLB operations avr32: Rename at32ap.c -> pdc.c avr32: Move setup_platform() into chip-specific file avr32: Kill special exception handler sections avr32: Kill unneeded #include <asm/pgalloc.h> from asm/mmu_context.h avr32: Clean up time.c #includes ...
2008-07-14Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6Linus Torvalds
* 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6: (71 commits) [S390] sclp_tty: Fix scheduling while atomic bug. [S390] sclp_tty: remove ioctl interface. [S390] Remove P390 support. [S390] Cleanup vmcp printk messages. [S390] Cleanup lcs printk messages. [S390] Cleanup kprobes printk messages. [S390] Cleanup vmwatch printk messages. [S390] Cleanup dcssblk printk messages. [S390] Cleanup zfcp dumper printk messages. [S390] Cleanup vmlogrdr printk messages. [S390] Cleanup s390 debug feature print messages. [S390] Cleanup monreader printk messages. [S390] Cleanup appldata printk messages. [S390] Cleanup smsgiucv printk messages. [S390] Cleanup cpacf printk messages. [S390] Cleanup qeth print messages. [S390] Cleanup netiucv printk messages. [S390] Cleanup iucv printk messages. [S390] Cleanup sclp printk messages. [S390] Cleanup zcrypt printk messages. ...
2008-07-14Start using the new '%pS' infrastructure to print symbolsLinus Torvalds
This simplifies the code significantly, and was the whole point of the exercise. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-14Merge branch 'auto-ftrace-next' into tracing/for-linusIngo Molnar
Conflicts: arch/x86/kernel/entry_32.S arch/x86/kernel/process_32.c arch/x86/kernel/process_64.c arch/x86/lib/Makefile include/asm-x86/irqflags.h kernel/Makefile kernel/sched.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-14[S390] Add support for memory hot-add.Heiko Carstens
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14Merge commit 'origin/HEAD' into test-mergeBenjamin Herrenschmidt
Manual fixup of include/asm-powerpc/pgtable-ppc64.h
2008-07-12Merge branch 'linus' into x86/coreIngo Molnar
Conflicts: arch/x86/mm/ioremap.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-11mm: Add range_cont mode for writebackAneesh Kumar K.V
Filesystems like ext4 needs to start a new transaction in the writepages for block allocation. This happens with delayed allocation and there is limit to how many credits we can request from the journal layer. So we call write_cache_pages multiple times with wbc->nr_to_write set to the maximum possible value limitted by the max journal credits available. Add a new mode to writeback that enables us to handle this behaviour. In the new mode we update the wbc->range_start to point to the new offset to be written. Next call to call to write_cache_pages will start writeout from specified range_start offset. In the new mode we also limit writing to the specified wbc->range_end. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-11vfs: export filemap_fdatawrite_range()Jan Kara
Make filemap_fdatawrite_range() function public, so that it can later be used in ordered mode rewrite by JBD/JBD2. Signed-off-by: Jan Kara <jack@suse.cz>
2008-07-10slub: Fix use-after-preempt of per-CPU data structureDmitry Adamushko
Vegard Nossum reported a crash in kmem_cache_alloc(): BUG: unable to handle kernel paging request at da87d000 IP: [<c01991c7>] kmem_cache_alloc+0xc7/0xe0 *pde = 28180163 *pte = 1a87d160 Oops: 0002 [#1] PREEMPT SMP DEBUG_PAGEALLOC Pid: 3850, comm: grep Not tainted (2.6.26-rc9-00059-gb190333 #5) EIP: 0060:[<c01991c7>] EFLAGS: 00210203 CPU: 0 EIP is at kmem_cache_alloc+0xc7/0xe0 EAX: 00000000 EBX: da87c100 ECX: 1adad71a EDX: 6b6b6b6b ESI: 00200282 EDI: da87d000 EBP: f60bfe74 ESP: f60bfe54 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 and analyzed it: "The register %ecx looks innocent but is very important here. The disassembly: mov %edx,%ecx shr $0x2,%ecx rep stos %eax,%es:(%edi) <-- the fault So %ecx has been loaded from %edx... which is 0x6b6b6b6b/POISON_FREE. (0x6b6b6b6b >> 2 == 0x1adadada.) %ecx is the counter for the memset, from here: memset(object, 0, c->objsize); i.e. %ecx was loaded from c->objsize, so "c" must have been freed. Where did "c" come from? Uh-oh... c = get_cpu_slab(s, smp_processor_id()); This looks like it has very much to do with CPU hotplug/unplug. Is there a race between SLUB/hotplug since the CPU slab is used after it has been freed?" Good analysis. Yeah, it's possible that a caller of kmem_cache_alloc() -> slab_alloc() can be migrated on another CPU right after local_irq_restore() and before memset(). The inital cpu can become offline in the mean time (or a migration is a consequence of the CPU going offline) so its 'kmem_cache_cpu' structure gets freed ( slab_cpuup_callback). At some point of time the caller continues on another CPU having an obsolete pointer... Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Reported-by: Vegard Nossum <vegard.nossum@gmail.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-10Merge branch 'tracing/ftrace' into auto-ftrace-nextIngo Molnar
2008-07-09mm: Allow architectures to define additional protection bitsDave Kleikamp
This patch allows architectures to define functions to deal with additional protections bits for mmap() and mprotect(). arch_calc_vm_prot_bits() maps additonal protection bits to vm_flags arch_vm_get_page_prot() maps additional vm_flags to the vma's vm_page_prot arch_validate_prot() checks for valid values of the protection bits Note: vm_get_page_prot() is now pretty ugly, but the generated code should be identical for architectures that don't define additional protection bits. Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-08mm, generic, x86 boot: more tweaks to hex prints of some pfn addressesPaul Jackson
Fix some problems with (and applies on top of) a previous patch: x86 boot: show pfn addresses in hex not decimal in some kernel info printks Primarily change "0x%8lx" format, which displays with a right aligned space filled hex number (spaces between the "0x" prefix and the number), into "%0#10lx" format, which zero fills instead of space fills, and which uses the printf flag '#' to request the "0x" prefix instead of hard coding it. Also replace some other "0x%lx" formats with "%#lx", making use of the '#' printf flag again. Signed-off-by: Paul Jackson <pj@sgi.com> Cc: "Yinghai Lu" <yhlu.kernel@gmail.com> Cc: "Jack Steiner" <steiner@sgi.com> Cc: "Mike Travis" <travis@sgi.com> Cc: "Huang Cc: Ying" <ying.huang@intel.com> Cc: "Andi Kleen" <andi@firstfloor.org> Cc: "Andrew Morton" <akpm@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08x86 boot: more consistently use type int for node idsPaul Jackson
Everywhere I look, node id's are of type 'int', except in this one case, which has 'unsigned long'. Change this one to 'int' as well. There is nothing special about the way this variable 'nid' is used in this routine to justify using an unusual type here. Signed-off-by: Paul Jackson <pj@sgi.com> Cc: "Yinghai Lu" <yhlu.kernel@gmail.com> Cc: "Jack Steiner" <steiner@sgi.com> Cc: "Mike Travis" <travis@sgi.com> Cc: "Huang Cc: Ying" <ying.huang@intel.com> Cc: "Andi Kleen" <andi@firstfloor.org> Cc: "Andrew Morton" <akpm@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08x86 boot: show pfn addresses in hex not decimal in some kernel info printksPaul Jackson
Page frame numbers (the portion of physical addresses above the low order page offsets) are displayed in several kernel debug and info prints in decimal, not hex. Decimal addresse are unreadable. Use hex. Signed-off-by: Paul Jackson <pj@sgi.com> Cc: "Yinghai Lu" <yhlu.kernel@gmail.com> Cc: "Jack Steiner" <steiner@sgi.com> Cc: "Mike Travis" <travis@sgi.com> Cc: "Huang Cc: Ying" <ying.huang@intel.com> Cc: "Andi Kleen" <andi@firstfloor.org> Cc: "Andrew Morton" <akpm@linux-foundation.org> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08RFC x86: try to remove arch_get_ram_rangeYinghai Lu
want to remove arch_get_ram_range, and use early_node_map instead. Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08Merge branch 'x86/mpparse' into x86/develIngo Molnar
Conflicts: arch/x86/Kconfig arch/x86/kernel/io_apic_32.c arch/x86/kernel/setup_64.c arch/x86/mm/init_32.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08x86, mm: use add_highpages_with_active_regions() for high pages init v2Yinghai Lu
use early_node_map to init high pages, so we can remove page_is_ram() and page_is_reserved_early() in the big loop with add_one_highpage also remove page_is_reserved_early(), it is not needed anymore. v2: fix the build of other platforms Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08x86: replace shrink_active_range() with remove_active_range()Yinghai Lu
in case we have kva before ramdisk on a node, we still need to use those ranges. v2: reserve_early kva ram area, in case there are holes in highmem, to avoid those area could be treat as free high pages. Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08Merge branch 'linus' into tmp.x86.mpparse.newIngo Molnar
2008-07-08Merge branches 'x86/numa-fixes', 'x86/apic', 'x86/apm', 'x86/bitops', ↵Ingo Molnar
'x86/build', 'x86/cleanups', 'x86/cpa', 'x86/cpu', 'x86/defconfig', 'x86/gart', 'x86/i8259', 'x86/intel', 'x86/irqstats', 'x86/kconfig', 'x86/ldt', 'x86/mce', 'x86/memtest', 'x86/pat', 'x86/ptemask', 'x86/resumetrace', 'x86/threadinfo', 'x86/timers', 'x86/vdso' and 'x86/xen' into x86/devel
2008-07-04mempolicy: mask off internal flags for userspace APIDavid Rientjes
Flags considered internal to the mempolicy kernel code are stored as part of the "flags" member of struct mempolicy. Before exposing a policy type to userspace via get_mempolicy(), these internal flags must be masked. Flags exposed to userspace, however, should still be returned to the user. Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-04get_user_pages(): fix possible page leak on oomOleg Nesterov
get_user_pages() must not return the error when i != 0. When pages != NULL we have i get_page()'ed pages. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-04mm: dirty page accounting vs VM_MIXEDMAPPeter Zijlstra
Dirty page accounting accurately measures the amound of dirty pages in writable shared mappings by mapping the pages RO (as indicated by vma_wants_writenotify). We then trap on first write and call set_page_dirty() on the page, after which we map the page RW and continue execution. When we launder dirty pages, we call clear_page_dirty_for_io() which clears both the dirty flag, and maps the page RO again before we start writeout so that the story can repeat itself. vma_wants_writenotify() excludes VM_PFNMAP on the basis that we cannot do the regular dirty page stuff on raw PFNs and the memory isn't going anywhere anyway. The recently introduced VM_MIXEDMAP mixes both !pfn_valid() and pfn_valid() pages in a single mapping. We can't do dirty page accounting on !pfn_valid() pages as stated above, and mapping them RO causes them to be COW'ed on write, which breaks VM_SHARED semantics. Excluding VM_MIXEDMAP in vma_wants_writenotify() would mean we don't do the regular dirty page accounting for the pfn_valid() pages, which would bring back all the head-aches from inaccurate dirty page accounting. So instead, we let the !pfn_valid() pages get mapped RO, but fix them up unconditionally in the fault path. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Hugh Dickins <hugh@veritas.com> Cc: "Jared Hulbert" <jaredeh@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-04Christoph has movedChristoph Lameter
Remove all clameter@sgi.com addresses from the kernel tree since they will become invalid on June 27th. Change my maintainer email address for the slab allocators to cl@linux-foundation.org (which will be the new email address for the future). Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-04Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6: slub: Do not use 192 byte sized cache if minimum alignment is 128 byte
2008-07-03Do not overwrite nr_zones on !NUMA when initialising zlcache_ptrMel Gorman
The non-NUMA case of build_zonelist_cache() would initialize the zlcache_ptr for both node_zonelists[] to NULL. Which is problematic, since non-NUMA only has a single node_zonelists[] entry, and trying to zero the non-existent second one just overwrote the nr_zones field instead. As kswapd uses this value to determine what reclaim work is necessary, the result is that kswapd never reclaims. This causes processes to stall frequently in low-memory situations as they always direct reclaim. This patch initialises zlcache_ptr correctly. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Tested-by: Dan Williams <dan.j.williams@intel.com> [ Simplified patch a bit ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-03slub: Do not use 192 byte sized cache if minimum alignment is 128 byteChristoph Lameter
The 192 byte cache is not necessary if we have a basic alignment of 128 byte. If it would be used then the 192 would be aligned to the next 128 byte boundary which would result in another 256 byte cache. Two 256 kmalloc caches cause sysfs to complain about a duplicate entry. MIPS needs 128 byte aligned kmalloc caches and spits out warnings on boot without this patch. Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-07-02avr32: Use a quicklist for PTE allocation as wellHaavard Skinnemoen
Using a quicklist to allocate PTEs might be slightly faster than using the page allocator directly since we might avoid zeroing the page after each allocation. Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-06-26on_each_cpu(): kill unused 'retry' parameterJens Axboe
It's not even passed on to smp_call_function() anymore, since that was removed. So kill it. Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-06-25mm: add a ptep_modify_prot transaction abstractionJeremy Fitzhardinge
This patch adds an API for doing read-modify-write updates to a pte's protection bits which may race against hardware updates to the pte. After reading the pte, the hardware may asynchonously set the accessed or dirty bits on a pte, which would be lost when writing back the modified pte value. The existing technique to handle this race is to use ptep_get_and_clear() atomically fetch the old pte value and clear it in memory. This has the effect of marking the pte as non-present, which will prevent the hardware from updating its state. When the new value is written back, the pte will be present again, and the hardware can resume updating the access/dirty flags. When running in a virtualized environment, pagetable updates are relatively expensive, since they generally involve some trap into the hypervisor. To mitigate the cost of these updates, we tend to batch them. However, because of the atomic nature of ptep_get_and_clear(), it is inherently non-batchable. This new interface allows batching by giving the underlying implementation enough information to open a transaction between the read and write phases: ptep_modify_prot_start() returns the current pte value, and puts the pte entry into a state where either the hardware will not update the pte, or if it does, the updates will be preserved on commit. ptep_modify_prot_commit() writes back the updated pte, makes sure that any hardware updates made since ptep_modify_prot_start() are preserved. ptep_modify_prot_start() and _commit() must be exactly paired, and used while holding the appropriate pte lock. They do not protect against other software updates of the pte in any way. The current implementations of ptep_modify_prot_start and _commit are functionally unchanged from before: _start() uses ptep_get_and_clear() fetch the pte and zero the entry, preventing any hardware updates. _commit() simply writes the new pte value back knowing that the hardware has not updated the pte in the meantime. The only current user of this interface is mprotect Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-25Merge branch 'linus' into tracing/ftraceIngo Molnar
2008-06-23mm: fix race in COW logicNick Piggin
There is a race in the COW logic. It contains a shortcut to avoid the COW and reuse the page if we have the sole reference on the page, however it is possible to have two racing do_wp_page()ers with one causing the other to mistakenly believe it is safe to take the shortcut when it is not. This could lead to data corruption. Process 1 and process2 each have a wp pte of the same anon page (ie. one forked the other). The page's mapcount is 2. Then they both attempt to write to it around the same time... proc1 proc2 thr1 proc2 thr2 CPU0 CPU1 CPU3 do_wp_page() do_wp_page() trylock_page() can_share_swap_page() load page mapcount (==2) reuse = 0 pte unlock copy page to new_page pte lock page_remove_rmap(page); trylock_page() can_share_swap_page() load page mapcount (==1) reuse = 1 ptep_set_access_flags (allow W) write private key into page read from page ptep_clear_flush() set_pte_at(pte of new_page) Fix this by moving the page_remove_rmap of the old page after the pte clear and flush. Potentially the entire branch could be moved down here, but in order to stay consistent, I won't (should probably move all the *_mm_counter stuff with one patch). Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Hugh Dickins <hugh@veritas.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-23Fix ZERO_PAGE breakage with vmwareLinus Torvalds
Commit 89f5b7da2a6bad2e84670422ab8192382a5aeb9f ("Reinstate ZERO_PAGE optimization in 'get_user_pages()' and fix XIP") broke vmware, as reported by Jeff Chua: "This broke vmware 6.0.4. Jun 22 14:53:03.845: vmx| NOT_IMPLEMENTED /build/mts/release/bora-93057/bora/vmx/main/vmmonPosix.c:774" and the reason seems to be that there's an old bug in how we handle do FOLL_ANON on VM_SHARED areas in get_user_pages(), but since it only triggered if the whole page table was missing, nobody had apparently hit it before. The recent changes to 'follow_page()' made the FOLL_ANON logic trigger not just for whole missing page tables, but for individual pages as well, and exposed this problem. This fixes it by making the test for when FOLL_ANON is used more careful, and also makes the code easier to read and understand by moving the logic to a separate inline function. Reported-and-tested-by: Jeff Chua <jeff.chua.linux@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-23Merge branch 'linus' into tracing/ftraceIngo Molnar
2008-06-21Slab: Fix memory leak in fallback_alloc()Christoph Lameter
The zonelist patches caused the loop that checks for available objects in permitted zones to not terminate immediately. One object per zone per allocation may be allocated and then abandoned. Break the loop when we have successfully allocated one object. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-21Add return value to reserve_bootmem_node()Bernhard Walle
This patch changes the function reserve_bootmem_node() from void to int, returning -ENOMEM if the allocation fails. This fixes a build problem on x86 with CONFIG_KEXEC=y and CONFIG_NEED_MULTIPLE_NODES=y Signed-off-by: Bernhard Walle <bwalle@suse.de> Reported-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-20Reinstate ZERO_PAGE optimization in 'get_user_pages()' and fix XIPLinus Torvalds
KAMEZAWA Hiroyuki and Oleg Nesterov point out that since the commit 557ed1fa2620dc119adb86b34c614e152a629a80 ("remove ZERO_PAGE") removed the ZERO_PAGE from the VM mappings, any users of get_user_pages() will generally now populate the VM with real empty pages needlessly. We used to get the ZERO_PAGE when we did the "handle_mm_fault()", but since fault handling no longer uses ZERO_PAGE for new anonymous pages, we now need to handle that special case in follow_page() instead. In particular, the removal of ZERO_PAGE effectively removed the core file writing optimization where we would skip writing pages that had not been populated at all, and increased memory pressure a lot by allocating all those useless newly zeroed pages. This reinstates the optimization by making the unmapped PTE case the same as for a non-existent page table, which already did this correctly. While at it, this also fixes the XIP case for follow_page(), where the caller could not differentiate between the case of a page that simply could not be used (because it had no "struct page" associated with it) and a page that just wasn't mapped. We do that by simply returning an error pointer for pages that could not be turned into a "struct page *". The error is arbitrarily picked to be EFAULT, since that was what get_user_pages() already used for the equivalent IO-mapped page case. [ Also removed an impossible test for pte_offset_map_lock() failing: that's not how that function works ] Acked-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-16Merge branch 'linus' into tracing/ftraceIngo Molnar