05 Oct, 2006

1 commit

  • Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
    of passing regs around manually through all ~1800 interrupt handlers in the
    Linux kernel.

    The regs pointer is used in few places, but it potentially costs both stack
    space and code to pass it around. On the FRV arch, removing the regs parameter
    from all the genirq function results in a 20% speed up of the IRQ exit path
    (ie: from leaving timer_interrupt() to leaving do_IRQ()).

    Where appropriate, an arch may override the generic storage facility and do
    something different with the variable. On FRV, for instance, the address is
    maintained in GR28 at all times inside the kernel as part of general exception
    handling.

    Having looked over the code, it appears that the parameter may be handed down
    through up to twenty or so layers of functions. Consider a USB character
    device attached to a USB hub, attached to a USB controller that posts its
    interrupts through a cascaded auxiliary interrupt controller. A character
    device driver may want to pass regs to the sysrq handler through the input
    layer which adds another few layers of parameter passing.

    I've build this code with allyesconfig for x86_64 and i386. I've runtested the
    main part of the code on FRV and i386, though I can't test most of the drivers.
    I've also done partial conversion for powerpc and MIPS - these at least compile
    with minimal configurations.

    This will affect all archs. Mostly the changes should be relatively easy.
    Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

    struct pt_regs *old_regs = set_irq_regs(regs);

    And put the old one back at the end:

    set_irq_regs(old_regs);

    Don't pass regs through to generic_handle_irq() or __do_IRQ().

    In timer_interrupt(), this sort of change will be necessary:

    - update_process_times(user_mode(regs));
    - profile_tick(CPU_PROFILING, regs);
    + update_process_times(user_mode(get_irq_regs()));
    + profile_tick(CPU_PROFILING);

    I'd like to move update_process_times()'s use of get_irq_regs() into itself,
    except that i386, alone of the archs, uses something other than user_mode().

    Some notes on the interrupt handling in the drivers:

    (*) input_dev() is now gone entirely. The regs pointer is no longer stored in
    the input_dev struct.

    (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
    something different depending on whether it's been supplied with a regs
    pointer or not.

    (*) Various IRQ handler function pointers have been moved to type
    irq_handler_t.

    Signed-Off-By: David Howells
    (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

    David Howells
     

02 Oct, 2006

1 commit

  • Define a per-container pid space object. And create one instance of this
    object, init_pspace, to define the entire pid space. Subsequent patches
    will provide/use interfaces to create/destroy pid spaces.

    Its a subset/rework of Eric Biederman's patch
    http://lkml.org/lkml/2006/2/6/285 .

    Signed-off-by: Eric Biederman
    Signed-off-by: Sukadev Bhattiprolu
    Cc: Dave Hansen
    Cc: Serge Hallyn
    Cc: Cedric Le Goater
    Cc: Kirill Korotaev
    Cc: Andrey Savochkin
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Sukadev Bhattiprolu
     

01 Oct, 2006

1 commit

  • Make it possible to disable the block layer. Not all embedded devices require
    it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
    the block layer to be present.

    This patch does the following:

    (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
    support.

    (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
    an item that uses the block layer. This includes:

    (*) Block I/O tracing.

    (*) Disk partition code.

    (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.

    (*) The SCSI layer. As far as I can tell, even SCSI chardevs use the
    block layer to do scheduling. Some drivers that use SCSI facilities -
    such as USB storage - end up disabled indirectly from this.

    (*) Various block-based device drivers, such as IDE and the old CDROM
    drivers.

    (*) MTD blockdev handling and FTL.

    (*) JFFS - which uses set_bdev_super(), something it could avoid doing by
    taking a leaf out of JFFS2's book.

    (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
    linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is,
    however, still used in places, and so is still available.

    (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
    parts of linux/fs.h.

    (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.

    (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.

    (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
    is not enabled.

    (*) fs/no-block.c is created to hold out-of-line stubs and things that are
    required when CONFIG_BLOCK is not set:

    (*) Default blockdev file operations (to give error ENODEV on opening).

    (*) Makes some /proc changes:

    (*) /proc/devices does not list any blockdevs.

    (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.

    (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.

    (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
    given command other than Q_SYNC or if a special device is specified.

    (*) In init/do_mounts.c, no reference is made to the blockdev routines if
    CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2.

    (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
    error ENOSYS by way of cond_syscall if so).

    (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
    CONFIG_BLOCK is not set, since they can't then happen.

    Signed-Off-By: David Howells
    Signed-off-by: Jens Axboe

    David Howells
     

26 Sep, 2006

2 commits

  • Remove the atomic counter for slab_reclaim_pages and replace the counter
    and NR_SLAB with two ZVC counter that account for unreclaimable and
    reclaimable slab pages: NR_SLAB_RECLAIMABLE and NR_SLAB_UNRECLAIMABLE.

    Change the check in vmscan.c to refer to to NR_SLAB_RECLAIMABLE. The
    intend seems to be to check for slab pages that could be freed.

    Signed-off-by: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Christoph Lameter
     
  • Do not display HIGHMEM memory sizes if CONFIG_HIGHMEM is not set.

    Make HIGHMEM dependent texts and make display of highmem counters optional

    Some texts are depending on CONFIG_HIGHMEM.

    Remove those strings and remove the display of highmem counter values if
    CONFIG_HIGHMEM is not set.

    [akpm@osdl.org: remove some ifdefs]
    Signed-off-by: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Christoph Lameter
     

28 Aug, 2006

1 commit


01 Jul, 2006

11 commits

  • * git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial:
    Remove obsolete #include
    remove obsolete swsusp_encrypt
    arch/arm26/Kconfig typos
    Documentation/IPMI typos
    Kconfig: Typos in net/sched/Kconfig
    v9fs: do not include linux/version.h
    Documentation/DocBook/mtdnand.tmpl: typo fixes
    typo fixes: specfic -> specific
    typo fixes in Documentation/networking/pktgen.txt
    typo fixes: occuring -> occurring
    typo fixes: infomation -> information
    typo fixes: disadvantadge -> disadvantage
    typo fixes: aquire -> acquire
    typo fixes: mecanism -> mechanism
    typo fixes: bandwith -> bandwidth
    fix a typo in the RTC_CLASS help text
    smb is no longer maintained

    Manually merged trivial conflict in arch/um/kernel/vmlinux.lds.S

    Linus Torvalds
     
  • Conversion of nr_bounce to a per zone counter

    nr_bounce is only used for proc output. So it could be left as an event
    counter. However, the event counters may not be accurate and nr_bounce is
    categorizing types of pages in a zone. So we really need this to also be a
    per zone counter.

    [akpm@osdl.org: bugfix]
    Signed-off-by: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Christoph Lameter
     
  • Conversion of nr_unstable to a per zone counter

    We need to do some special modifications to the nfs code since there are
    multiple cases of disposition and we need to have a page ref for proper
    accounting.

    This converts the last critical page state of the VM and therefore we need to
    remove several functions that were depending on GET_PAGE_STATE_LAST in order
    to make the kernel compile again. We are only left with event type counters
    in page state.

    [akpm@osdl.org: bugfixes]
    Signed-off-by: Christoph Lameter
    Cc: Trond Myklebust
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Christoph Lameter
     
  • Conversion of nr_writeback to per zone counter.

    This removes the last page_state counter from arch/i386/mm/pgtable.c so we
    drop the page_state from there.

    [akpm@osdl.org: bugfix]
    Signed-off-by: Christoph Lameter
    Cc: Trond Myklebust
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Christoph Lameter
     
  • This makes nr_dirty a per zone counter. Looping over all processors is
    avoided during writeback state determination.

    The counter aggregation for nr_dirty had to be undone in the NFS layer since
    we summed up the page counts from multiple zones. Someone more familiar with
    NFS should probably review what I have done.

    [akpm@osdl.org: bugfix]
    Signed-off-by: Christoph Lameter
    Cc: Trond Myklebust
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Christoph Lameter
     
  • Conversion of nr_page_table_pages to a per zone counter

    [akpm@osdl.org: bugfix]
    Signed-off-by: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Christoph Lameter
     
  • - Allows reclaim to access counter without looping over processor counts.

    - Allows accurate statistics on how many pages are used in a zone by
    the slab. This may become useful to balance slab allocations over
    various zones.

    [akpm@osdl.org: bugfix]
    Signed-off-by: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Christoph Lameter
     
  • The current NR_FILE_MAPPED is used by zone reclaim and the dirty load
    calculation as the number of mapped pagecache pages. However, that is not
    true. NR_FILE_MAPPED includes the mapped anonymous pages. This patch
    separates those and therefore allows an accurate tracking of the anonymous
    pages per zone.

    It then becomes possible to determine the number of unmapped pages per zone
    and we can avoid scanning for unmapped pages if there are none.

    Also it may now be possible to determine the mapped/unmapped ratio in
    get_dirty_limit. Isnt the number of anonymous pages irrelevant in that
    calculation?

    Note that this will change the meaning of the number of mapped pages reported
    in /proc/vmstat /proc/meminfo and in the per node statistics. This may affect
    user space tools that monitor these counters! NR_FILE_MAPPED works like
    NR_FILE_DIRTY. It is only valid for pagecache pages.

    Signed-off-by: Christoph Lameter
    Cc: Trond Myklebust
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Christoph Lameter
     
  • Currently a single atomic variable is used to establish the size of the page
    cache in the whole machine. The zoned VM counters have the same method of
    implementation as the nr_pagecache code but also allow the determination of
    the pagecache size per zone.

    Remove the special implementation for nr_pagecache and make it a zoned counter
    named NR_FILE_PAGES.

    Updates of the page cache counters are always performed with interrupts off.
    We can therefore use the __ variant here.

    Signed-off-by: Christoph Lameter
    Cc: Trond Myklebust
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Christoph Lameter
     
  • nr_mapped is important because it allows a determination of how many pages of
    a zone are not mapped, which would allow a more efficient means of determining
    when we need to reclaim memory in a zone.

    We take the nr_mapped field out of the page state structure and define a new
    per zone counter named NR_FILE_MAPPED (the anonymous pages will be split off
    from NR_MAPPED in the next patch).

    We replace the use of nr_mapped in various kernel locations. This avoids the
    looping over all processors in try_to_free_pages(), writeback, reclaim (swap +
    zone reclaim).

    [akpm@osdl.org: bugfix]
    Signed-off-by: Christoph Lameter
    Cc: Trond Myklebust
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Christoph Lameter
     
  • Signed-off-by: Jörn Engel
    Signed-off-by: Adrian Bunk

    Jörn Engel
     

01 Apr, 2006

1 commit

  • Make baby-simple the code for /proc/devices. Based on the proven design
    for /proc/interrupts.

    This also fixes the early-termination regression 2.6.16 introduced, as
    demonstrated by:

    # dd if=/proc/devices bs=1
    Character devices:
    1 mem
    27+0 records in
    27+0 records out

    This should also work (but is untested) when /proc/devices >4096 bytes,
    which I believe is what the original 2.6.16 rewrite fixed.

    [akpm@osdl.org: cleanups, simplifications]
    Signed-off-by: Joe Korty
    Cc: Neil Horman
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Joe Korty
     

29 Mar, 2006

2 commits


26 Mar, 2006

1 commit

  • Implement /proc/slab_allocators. It produces output like:

    idr_layer_cache: 80 idr_pre_get+0x33/0x4e
    buffer_head: 2555 alloc_buffer_head+0x20/0x75
    mm_struct: 9 mm_alloc+0x1e/0x42
    mm_struct: 20 dup_mm+0x36/0x370
    vm_area_struct: 384 dup_mm+0x18f/0x370
    vm_area_struct: 151 do_mmap_pgoff+0x2e0/0x7c3
    vm_area_struct: 1 split_vma+0x5a/0x10e
    vm_area_struct: 11 do_brk+0x206/0x2e2
    vm_area_struct: 2 copy_vma+0xda/0x142
    vm_area_struct: 9 setup_arg_pages+0x99/0x214
    fs_cache: 8 copy_fs_struct+0x21/0x133
    fs_cache: 29 copy_process+0xf38/0x10e3
    files_cache: 30 alloc_files+0x1b/0xcf
    signal_cache: 81 copy_process+0xbaa/0x10e3
    sighand_cache: 77 copy_process+0xe65/0x10e3
    sighand_cache: 1 de_thread+0x4d/0x5f8
    anon_vma: 241 anon_vma_prepare+0xd9/0xf3
    size-2048: 1 add_sect_attrs+0x5f/0x145
    size-2048: 2 journal_init_revoke+0x99/0x302
    size-2048: 2 journal_init_revoke+0x137/0x302
    size-2048: 2 journal_init_inode+0xf9/0x1c4

    Cc: Manfred Spraul
    Cc: Alexander Nyberg
    Cc: Pekka Enberg
    Cc: Christoph Lameter
    Cc: Ravikiran Thirumalai
    Signed-off-by: Al Viro
    DESC
    slab-leaks3-locking-fix
    EDESC
    From: Andrew Morton

    Update for slab-remove-cachep-spinlock.patch

    Cc: Al Viro
    Cc: Manfred Spraul
    Cc: Alexander Nyberg
    Cc: Pekka Enberg
    Cc: Christoph Lameter
    Cc: Ravikiran Thirumalai
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Al Viro
     

23 Mar, 2006

1 commit


04 Feb, 2006

1 commit


15 Jan, 2006

1 commit

  • A Christoph suggested that the /proc/devices file be converted to use the
    seq_file interface. This patch does that.

    I've obxerved one or two installation that had sufficiently large sans that
    they overran the 4k limit on /proc/devices.

    Signed-off-by: Neil Horman
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Neil Horman
     

09 Jan, 2006

1 commit

  • configurable replacement for slab allocator

    This adds a CONFIG_SLAB option under CONFIG_EMBEDDED. When CONFIG_SLAB is
    disabled, the kernel falls back to using the 'SLOB' allocator.

    SLOB is a traditional K&R/UNIX allocator with a SLAB emulation layer,
    similar to the original Linux kmalloc allocator that SLAB replaced. It's
    signicantly smaller code and is more memory efficient. But like all
    similar allocators, it scales poorly and suffers from fragmentation more
    than SLAB, so it's only appropriate for small systems.

    It's been tested extensively in the Linux-tiny tree. I've also
    stress-tested it with make -j 8 compiles on a 3G SMP+PREEMPT box (not
    recommended).

    Here's a comparison for otherwise identical builds, showing SLOB saving
    nearly half a megabyte of RAM:

    $ size vmlinux*
    text data bss dec hex filename
    3336372 529360 190812 4056544 3de5e0 vmlinux-slab
    3323208 527948 190684 4041840 3dac70 vmlinux-slob

    $ size mm/{slab,slob}.o
    text data bss dec hex filename
    13221 752 48 14021 36c5 mm/slab.o
    1896 52 8 1956 7a4 mm/slob.o

    /proc/meminfo:
    SLAB SLOB delta
    MemTotal: 27964 kB 27980 kB +16 kB
    MemFree: 24596 kB 25092 kB +496 kB
    Buffers: 36 kB 36 kB 0 kB
    Cached: 1188 kB 1188 kB 0 kB
    SwapCached: 0 kB 0 kB 0 kB
    Active: 608 kB 600 kB -8 kB
    Inactive: 808 kB 812 kB +4 kB
    HighTotal: 0 kB 0 kB 0 kB
    HighFree: 0 kB 0 kB 0 kB
    LowTotal: 27964 kB 27980 kB +16 kB
    LowFree: 24596 kB 25092 kB +496 kB
    SwapTotal: 0 kB 0 kB 0 kB
    SwapFree: 0 kB 0 kB 0 kB
    Dirty: 4 kB 12 kB +8 kB
    Writeback: 0 kB 0 kB 0 kB
    Mapped: 560 kB 556 kB -4 kB
    Slab: 1756 kB 0 kB -1756 kB
    CommitLimit: 13980 kB 13988 kB +8 kB
    Committed_AS: 4208 kB 4208 kB 0 kB
    PageTables: 28 kB 28 kB 0 kB
    VmallocTotal: 1007312 kB 1007312 kB 0 kB
    VmallocUsed: 48 kB 48 kB 0 kB
    VmallocChunk: 1007264 kB 1007264 kB 0 kB

    (this work has been sponsored in part by CELF)

    From: Ingo Molnar

    Fix 32-bitness bugs in mm/slob.c.

    Signed-off-by: Matt Mackall
    Signed-off-by: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Matt Mackall
     

26 Sep, 2005

1 commit

  • This creates the directory structure under arch/powerpc and a bunch
    of Kconfig files. It does a first-cut merge of arch/powerpc/mm,
    arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough
    to build a 32-bit powermac kernel with ARCH=powerpc.

    For now we are getting some unmerged files from arch/ppc/kernel and
    arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes
    to files in those directories and files outside arch/powerpc.

    The boot directory is still not merged. That's going to be interesting.

    Signed-off-by: Paul Mackerras

    Paul Mackerras
     

26 Jun, 2005

1 commit

  • From: "Vivek Goyal"

    o Support for /proc/vmcore interface. This interface exports elf core image
    either in ELF32 or ELF64 format, depending on the format in which elf headers
    have been stored by crashed kernel.
    o Added support for CONFIG_VMCORE config option.
    o Removed the dependency on /proc/kcore.

    From: "Eric W. Biederman"

    This patch has been refactored to more closely match the prevailing style in
    the affected files. And to clearly indicate the dependency between
    /proc/kcore and proc/vmcore.c

    From: Hariprasad Nellitheertha

    This patch contains the code that provides an ELF format interface to the
    previous kernel's memory post kexec reboot.

    Signed off by Hariprasad Nellitheertha
    Signed-off-by: Eric Biederman
    Signed-off-by: Vivek Goyal
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Vivek Goyal
     

24 Jun, 2005

1 commit

  • Patch to add check to get_chrdev_list and get_blkdev_list to prevent reads
    of /proc/devices from spilling over the provided page if more than 4096
    bytes of string data are generated from all the registered character and
    block devices in a system

    Signed-off-by: Neil Horman
    Cc: Christoph Hellwig
    Cc:
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Neil Horman
     

22 Jun, 2005

1 commit


17 Apr, 2005

2 commits

  • Working on some code lately I've been getting huge values for "Cached".
    The cause is that get_page_cache_size() is an approximate value, and for a
    sufficiently small returned value of get_page_cache_size() the value
    underflows.

    Signed-off-by: Martin Hicks
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Martin Hicks
     
  • Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds