1. 24 Aug, 2004 40 commits
    • Christoph Hellwig's avatar
      [PATCH] BUG() on inconsistant dcache tree in may_delete · 5db90d87
      Christoph Hellwig authored
      This can't happen with a sane filesystem (but is triggered by the buggy
      clearcase bin only kernel module), so let's better BUG_ON early.
      
      Adopted from Al's patch in the RH tree.
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      5db90d87
    • Christoph Hellwig's avatar
      [PATCH] reduce pty.c ifdef clutter · daf178a7
      Christoph Hellwig authored
      - build only if either CONFIG_LEGACY_PTYS or CONFIG_UNIX98_PTYS are set
        instead of testing in the file
      
      - try to keep big CONFIG_LEGACY_PTYS and CONFIG_UNIX98_PTYS ifdef blocks
        at the end of the file instead of cluttering all over
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      daf178a7
    • Jesse Barnes's avatar
      [PATCH] fix sn_console for CONFIG_SMP=n · a64a3bab
      Jesse Barnes authored
      I found that sn_console was missing an include and a fix if CONFIG_SMP=n.  
      This patch fixes up the two small problems I found.
      Signed-off-by: default avatarJesse Barnes <jbarnes@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      a64a3bab
    • Jesse Barnes's avatar
      [PATCH] don't print per-cpu delay loop calibration · 887c8014
      Jesse Barnes authored
      People are mainly concerned with showing off their total bogomips, not
      per-cpu bogomips, so turn it into a KERN_DEBUG message for the benefit of
      systems with lots of CPUs.
      Signed-off-by: default avatarJesse Barnes <jbarnes@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      887c8014
    • James Morris's avatar
      [PATCH] libfs: move transaction file ops into libfs · f22f9ade
      James Morris authored
      Below is an updated version of the patch which moves duplicated
      transaction-based file operation code into libfs.  Since the last post, the
      patch has been through a couple of iterations with Al, who suggested a
      number of cleanups including locking and interface simplification.
      
      For filesystem writers, the interface is now much simpler.  The
      simple_transaction_get() helper should be part of the file op write method.
       This safely obtains the transaction request data during write(), allocates
      a page for it and stores it there.  The data is returned to the caller for
      potential further processing, which then makes it available for the next
      read() call via simple_transaction_set().  See the selinuxfs and nfsctl
      code for examples of use.
      Signed-off-by: default avatarJames Morris <jmorris@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      f22f9ade
    • Pawel Sikora's avatar
      [PATCH] ix86,x86_64 cpu features · ef53b198
      Pawel Sikora authored
      Attached patch fix/add several cpu features.
      
      refs:
      
      [1] Intel Processor Identification and the CPUID instruction
          Application Note 485.
          http://developer.intel.ru/download/design/Xeon/applnots/24161826.pdf
      
      [2] http://www.sandpile.org/ia32/cpuid.htmSigned-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      ef53b198
    • Dave Jones's avatar
      [PATCH] x86: quieten the "ESR value" printks · c7209ef9
      Dave Jones authored
      Only print out the ESR value if it changes after enabling vector.
      Signed-off-by: default avatarDave Jones <davej@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      c7209ef9
    • Ben Leslie's avatar
      [PATCH] Use posix headers in sumversion.c · 2c4fc034
      Ben Leslie authored
      When compiling Linux on Mac OSX I had trouble with scripts/sumversion.c.
      It includes <netinet/in.h> to obtain to definitions of htonl and ntohl.
      
      On Mac OSX these are found in <arpa/inet.h>.  After checking the POSIX
      specification it appears that this is the correct place to get the
      definitons for these functions.
      
      (http://www.opengroup.org/onlinepubs/009695399/functions/htonl.html)
      
      Using this header also appears to work on Linux (at least with
      Glibc-2.3.2).
      
      It seems clearer to me to go with the POSIX standard than implementing
      #if __APPLE__ style macros, but if such an approach is preferred I can
      supply patches for that instead.
      
      A patch against 2.6.7 which change <netinet/in.h> -> <arpa/inet.h> is
      attached.
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      2c4fc034
    • Brent Casavant's avatar
      [PATCH] Fix get_nodes() mask miscalculation · 70b9eca4
      Brent Casavant authored
      It appears there is a nodemask miscalculation in the get_nodes() function
      in mm/mempolicy.c.  This bug has two effects:
      
      1. It is impossible to specify a length 1 nodemask.
      2. It is impossible to specify a nodemask containing the last node.
      
      The following patch has been confirmed to solve both problems.
      Signed-off-by: default avatarBrent Casavant <bcasavan@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      70b9eca4
    • Michal Ludvig's avatar
      [PATCH] New cpu_has_ flags · c41c607c
      Michal Ludvig authored
      Add a couple more accessors for xstore features.
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      c41c607c
    • Paul Jackson's avatar
      [PATCH] hige2lowuid warning fixes · 53e31beb
      Paul Jackson authored
      fs/smbfs/inode.c: In function `smb_fill_super':
      fs/smbfs/inode.c:563: warning: comparison is always false due to limited range of data type
      
      Unfortunately, this patch uses the notorious "gcc warning suppression by
      obfuscation" technique.
      
      What seems to be going on is that the uid and gid convert macros in
      include/linux/highuid.h:
      
      #define __convert_uid(size, uid) \
              (size >= sizeof(uid) ? (uid) : high2lowuid(uid))
      
      only call high2lowuid in the case of trying to put a bigger (32 bit, say)
      uid/gid in a smaller (16 bit, in this case) word.  Gcc is smart enough to see
      that the comparison in high2lowuid() macro is silly if called with a 16 bit
      source uid, but not smart enough to understand from the __convert_uid() logic
      that this is exactly the case that high2lowuid() won't be called.
      
      So replace the logical "<" operator with the bit op "&~".  This obfuscates
      things enough to shut gcc up.
      
      Only build the half-dozen files that use SET_UID/SET_GID, on arch i386 and
      ia64.  Only the file fs/smbfs/inode.c showed the warning, both arch's, and
      this patch fixed both.  Untested further, past staring at the code long enough
      to convince myself the change has no actual affect on the code's results.
      Signed-off-by: default avatarPaul Jackson <pj@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      53e31beb
    • Dave Jones's avatar
      [PATCH] fix inlining failures · dde7b964
      Dave Jones authored
      arch/i386/mach-generic/summit.c: In function `send_IPI_all':
      include/asm/mach-summit/mach_ipi.h:4: sorry, unimplemented: inlining failed in call to 'send_IPI_mask_sequence': function body not available
      arch/i386/mach-generic/summit.c:8: sorry, unimplemented: called from here
      make[1]: *** [arch/i386/mach-generic/summit.o] Error 1
      make: *** [arch/i386/mach-generic] Error 2
      
      arch/i386/mach-generic/bigsmp.c: In function `send_IPI_all':
      include/asm/mach-bigsmp/mach_ipi.h:4: sorry, unimplemented: inlining failed in call to 'send_IPI_mask_sequence': function body not available
      arch/i386/mach-generic/bigsmp.c:8: sorry, unimplemented: called from here
      make[1]: *** [arch/i386/mach-generic/bigsmp.o] Error 1
      make: *** [arch/i386/mach-generic] Error 2
      
      arch/i386/mach-generic/es7000.c: In function `send_IPI_all':
      include/asm/mach-es7000/mach_ipi.h:4: sorry, unimplemented: inlining failed in call to 'send_IPI_mask_sequence': function body not available
      arch/i386/mach-generic/es7000.c:8: sorry, unimplemented: called from here
      make[1]: *** [arch/i386/mach-generic/es7000.o] Error 1
      make: *** [arch/i386/mach-generic] Error 2
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      dde7b964
    • Pawel Sikora's avatar
      [PATCH] apm_info.disabled fix · a71c59c4
      Pawel Sikora authored
      This minor fix is required to proper init "APM emulation" on HP-OmniBooks. 
      (An external patch).  "APM emulation" is very useful if you want to use a tool
      which looks into /proc/apm for getting informations about battery charging.
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      a71c59c4
    • Josh Aas's avatar
      [PATCH] Reduce bkl usage in do_coredump · 77dc05e7
      Josh Aas authored
      A patch that reduces bkl usage in do_coredump.  I don't see anywhere that
      it is necessary except for the call to format_corename, which is controlled
      via sysctl (sys_sysctl holds the bkl).
      
      Also make format_corename() static.
      Signed-off-by: default avatarJosh Aas <josha@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      77dc05e7
    • Andi Kleen's avatar
      [PATCH] Fix warnings in es7000 · 1f655232
      Andi Kleen authored
      Fix warnings in es7000. 
      
      Otherwise gcc 3.3 complains about too large integer values.
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      1f655232
    • Neil Brown's avatar
      [PATCH] md: RAID10 module · 5f8dbb56
      Neil Brown authored
      This patch adds a 'raid10' module which provides features similar to both
      raid0 and raid1 in the one array.  Various combinations of layout are
      supported.
      
      This code is still "experimental", but appears to work.
      Signed-off-by: default avatarNeil Brown <neilb@cse.unsw.edu.au>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      5f8dbb56
    • Neil Brown's avatar
      [PATCH] md: remove most calls to __bdevname from md.c · 3cf9857a
      Neil Brown authored
      __bdevname now only prints major/minor number which isn't much help.  So
      remove most calls to it from md.c, replacing those that are useful by calls
      to bdevname (often printing the message when the error is first detected
      rather than higher up the call tree).
      
      Also discard hot_generate_error which doesn't do anything useful and never
      has.
      Signed-off-by: default avatarNeil Brown <neilb@cse.unsw.edu.au>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      3cf9857a
    • Neil Brown's avatar
      [PATCH] md: assorted minor md/raid1 fixes · f57252ba
      Neil Brown authored
      1/ rationalise read_balance and "map" in raid1.  Discard map and
         tidyup the interface to read_balance so it can be used instead.
      
      2/ use offsetof rather than a caclulation to find the size of an
         structure with a var-length array at the end.
      
      3/ remove some meaningless #defines 
      
      4/ use printk_ratelimit to limit reports of failed sectors being redirected.
      Signed-off-by: default avatarNeil Brown <neilb@cse.unsw.edu.au>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      f57252ba
    • Neil Brown's avatar
      [PATCH] md: assorted fixes/improvemnet to generic md resync code. · 32c31806
      Neil Brown authored
      1/ Introduce "mddev->resync_max_sectors" so that an md personality
      can ask for resync to cover a different address range than that of a
      single drive.  raid10 will use this.
      
      2/ fix is_mddev_idle so that if there seem to be a negative number
       of events, it doesn't immediately assume activity.
      
      3/ make "sync_io" (the count of IO sectors used for array resync)
       an atomic_t to avoid SMP races. 
      
      4/ Pass md_sync_acct a "block_device" rather than the containing "rdev",
        as the whole rdev isn't needed. Also make this an inline function.
      
      5/ Make sure recovery gets interrupted on any error.
      Signed-off-by: default avatarNeil Brown <neilb@cse.unsw.edu.au>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      32c31806
    • William Lee Irwin III's avatar
      [PATCH] hugetlb: permit executable mappings · b60e5e71
      William Lee Irwin III authored
      During the kernel summit, some discussion was had about the support
      requirements for a userspace program loader that loads executables into
      hugetlb on behalf of a major application (Oracle).  In order to support
      this in a robust fashion, the cleanup of the hugetlb must be robust in the
      presence of disorderly termination of the programs (e.g.  kill -9).  Hence,
      the cleanup semantics are those of System V shared memory, but Linux'
      System V shared memory needs one critical extension for this use:
      executability.
      
      The following microscopic patch enables this major application to provide
      robust hugetlb cleanup.
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      b60e5e71
    • William Lee Irwin III's avatar
      [PATCH] x86 PAE swapspace expansion · 93ff3346
      William Lee Irwin III authored
      PAE is artificially limited in terms of swapspace to the same bitsplit as
      ordinary i386, a 5/24 split (32 swapfiles, 64GB max swapfile size), when a
      5/27 split (32 swapfiles, 512GB max swapfile size) is feasible.  This patch
      transparently removes that limitation by using more of the space available
      in PAE's wider ptes for swap ptes.
      
      While this is obviously not likely to be used directly, it is important
      from the standpoint of strict non-overcommit, where the swapspace must be
      potentially usable in order to be reserved for non-overcommit.  There are
      workloads with Committed_AS of over 256GB on ia32 PAE wanting strict
      non-overcommit to prevent being OOM killed.
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      93ff3346
    • Zwane Mwaikambo's avatar
      [PATCH] fix i386/x86_64 idle routine selection · 7177784e
      Zwane Mwaikambo authored
      This was broken when the mwait stuff went in since it executes after the
      initial idle_setup() has already selected an idle routine and overrides it
      with default_idle.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarZwane Mwaikambo <zwane@linuxpower.ca>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      7177784e
    • Manfred Spraul's avatar
      [PATCH] remove magic +1 from shm segment count · fefd81e1
      Manfred Spraul authored
      Michael Kerrisk found a bug in the shm accounting code: sysv shm allows to
      create SHMMNI+1 shared memory segments, instead of SHMMNI segments.  The +1
      is probably from the first shared anonymous mapping implementation that
      used the sysv code to implement shared anon mappings.
      
      The implementation got replaced, it's now the other way around (sysv uses
      the shared anon code), but the +1 remained.
      Signed-off-by: default avatarManfred Spraul <manfred@colorfullife.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      fefd81e1
    • Zwane Mwaikambo's avatar
      [PATCH] OProfile/XScale fixes for PXA270/XScale2 · 11c61286
      Zwane Mwaikambo authored
      The incorrect mask was being used when writing back to PMNC write-only-zero
      bits as well as only ticking the CCNT every 64 processor cycles.  Tested on
      IOP331 and PXA270, i'm still looking for XScale1 users...
      Signed-off-by: default avatarLuca Rossato <l.rossato@tiscali.it>
      Signed-off-by: default avatarZwane Mwaikambo <zwane@arm.linux.org.uk>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      11c61286
    • William Lee Irwin III's avatar
      [PATCH] kill CLONE_IDLETASK · 69c46983
      William Lee Irwin III authored
        The sole remaining usage of CLONE_IDLETASK is to determine whether pid
        allocation should be performed in copy_process().  This patch eliminates
        that last branch on CLONE_IDLETASK in the normal process creation path,
        removes the masking of CLONE_IDLETASK from clone_flags as it's now ignored
        under all circumstances, and furthermore eliminates the symbol
        CLONE_IDLETASK entirely.
      
      From: William Lee Irwin III <wli@holomorphy.com>
      
        Fix the fork-idle consolidation.  During that consolidation, the generic
        code was made to pass a pointer to on-stack pt_regs that had been memset()
        to 0.  ia64, however, requires a NULL pt_regs pointer argument and
        dispatches on that in its copy_thread() function to do SMP
        trampoline-specific RSE -related setup.  Passing pointers to zeroed pt_regs
        resulted in SMP wakeup -time deadlocks and exceptions.
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      69c46983
    • William Lee Irwin III's avatar
      [PATCH] sched: consolidate CLONE_IDLETASK masking · f4205a53
      William Lee Irwin III authored
      Every arch now bears the burden of sanitizing CLONE_IDLETASK out of the
      clone_flags passed to do_fork() by userspace.  This patch hoists the
      masking of CLONE_IDLETASK out of the system call entrypoints into
      do_fork(), and thereby removes some small overheads from do_fork(), as
      do_fork() may now assume that CLONE_IDLETASK has been cleared.
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      f4205a53
    • Josh Aas's avatar
      [PATCH] improve speed of freeing bootmem · fe92ebf3
      Josh Aas authored
      Attached is a patch that greatly improves the speed of freeing boot memory.
       On ia64 machines with 2GB or more memory (I didn't test with less, but I
      can't imagine there being a problem), the speed improvement is about 75%
      for the function free_all_bootmem_core.  This translates to savings on the
      order of 1 minute / TB of memory during boot time.  That number comes from
      testing on a machine with 512GB, and extrapolating based on profiling of an
      unpatched 4TB machine.  For 4 and 8 TB machines, the time spent in this
      function is about 1 minutes/TB, which is painful especially given that
      there is no indication of what is going on put to the console (this issue
      to possibly be addressed later).
      
      The basic idea is to free higher order pages instead of going through every
      single one.  Also, some unnecessary atomic operations are done away with
      and replaced with non-atomic equivalents, and prefetching is done where it
      helps the most.  For a more in-depth discusion of this patch, please see
      the linux-ia64 archives (topic is "free bootmem feedback patch").
      
      The patch is originally Tony Luck's, and I added some further optimizations
      (non-atomic ops improvements and prefetching).
      Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
      Signed-off-by: default avatarJosh Aas <josha@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      fe92ebf3
    • Badari Pulavarty's avatar
      [PATCH] Fix mpage_readpage() for big requests · 13c61952
      Badari Pulavarty authored
      The problem is, if we increase our readhead size arbitrarily (say 2M), we
      call mpage_readpages() with 2M and when it tries to allocated a bio enough to
      fit 2M it fails, then we kick it back to "confused" code - which does 4K at
      a time.
      
      The fix is to ask for the maxium the driver can handle.
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      13c61952
    • Roland Dreier's avatar
      [PATCH] x86: remove hard-coded numbers from ptr_ok() · 7b4731ff
      Roland Dreier authored
      Looks like arch/i386/kernel/doublefault.c is one place in the code that
      hardcodes the assumption that PAGE_OFFSET == 0xC0000000.  Here's a patch
      that fixes that.
      Signed-off-by: default avatarRoland Dreier <roland@topspin.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      7b4731ff
    • James Courtier-Dutton's avatar
      [PATCH] emu10k1 maintainer update · a12d5822
      James Courtier-Dutton authored
      Rui Sousa has been unreachable for a long time now, so I have taken over
      the emu10k1 project on sf.net.
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      a12d5822
    • Andrea Arcangeli's avatar
      [PATCH] Correctly handle d_path error returns · 72c21479
      Andrea Arcangeli authored
      There's some minor bug in the d_path handling (the nfsd one may not the the
      correct fix, there's no failure path for it, so I just terminate the
      string, and the last one in the audit subsystem is just a robustness
      cleanup if somebody will extend d_path in the future, right now it's a
      noop).
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      72c21479
    • Andrew Morton's avatar
      [PATCH] alloc_pages priority tuning · 29d15009
      Andrew Morton authored
      Fix up the logic which decides when the caller can dip into page reserves.
      
      - If the caller has realtime scheduling policy, or if the caller cannot run
        direct reclaim, then allow the caller to use up to a quarter of the page
        reserves.
      
      - If the caller has __GFP_HIGH then allow the caller to use up to half of
        the page reserves.
      
      - If the caller has PF_MEMALLOC then the caller can use 100% of the page
        reserves.
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      29d15009
    • Nick Piggin's avatar
      [PATCH] vm: alloc_pages watermark fixes · ac12db05
      Nick Piggin authored
      Previously the ->protection[] logic was broken.  It was difficult to follow
      and basically didn't use the asynch reclaim watermarks (pages_min,
      pages_low, pages_high) properly.
      
      Now use ->protection *only* for lower-zone protection.  So the allocator
      now explicitly uses the ->pages_low, ->pages_min watermarks and adds
      ->protection on top of that, instead of trying to use ->protection for
      everything.
      
      Pages are allocated down to (->pages_low + ->protection), once this is
      reached, kswapd the background reclaim is started; after this, we can
      allocate down to (->pages_min + ->protection) without blocking; the memory
      below pages_min is reserved for __GFP_HIGH and PF_MEMALLOC allocations. 
      kswapd attempts to reclaim memory until ->pages_high is reached.
      Signed-off-by: default avatarNick Piggin <nickpiggin@yahoo.com.au>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      ac12db05
    • Nick Piggin's avatar
      [PATCH] vm: writeout watermark tuning · 0d761325
      Nick Piggin authored
      Slightly change the writeout watermark calculations so we keep background
      and synchronous writeout watermarks in the same ratios after adjusting them
      for the amout of mapped memory.  This ensures we should always attempt to
      start background writeout before synchronous writeout and preserves the
      admin's desired background-versus-forground ratios after we've
      auto-adjusted one of them.
      Signed-off-by: default avatarNick Piggin <nickpiggin@cyberone.com.au>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      0d761325
    • Hugh Dickins's avatar
      [PATCH] simple fs stop -ve dentries · 8a34e562
      Hugh Dickins authored
      A tmpfs user reported increasingly slow directory reads when repeatedly
      creating and unlinking in a mkstemp-like way.  The negative dentries
      accumulate alarmingly (until memory pressure finally frees them), and are
      just a hindrance to any in-memory filesystem.  simple_lookup set d_op to
      arrange for negative dentries to be deleted immediately.
      
      (But I failed to discover how it is that on-disk filesystems seem to keep
      their negative dentries within manageable bounds: this effect was gross
      with tmpfs or ramfs, but no problem at all with extN or reiser.)
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      8a34e562
    • Hugh Dickins's avatar
      [PATCH] clarify get_task_mm (mmgrab) · 7dbb1d67
      Hugh Dickins authored
      Clarify mmgrab by collapsing it into get_task_mm (in fork.c not inline),
      and commenting on the special case it is guarding against: when use_mm in
      an AIO daemon temporarily adopts the mm while it's on its way out.
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      7dbb1d67
    • Marcelo Tosatti's avatar
      [PATCH] x86 bitops.h commentary on instruction reordering · c524e494
      Marcelo Tosatti authored
      Back when we were discussing the need for a memory barrier in sync_page(),
      it came to me (thanks Andrea!) that the bit operations can be perfectly
      reordered on architectures other than x86.
      
      I think the commentary on i386 bitops.h is misleading, its worth to note
      that that these operations are not guaranteed not to be reordered on
      different architectures.
      
      clear_bit() already does that:
      
       * clear_bit() is atomic and may not be reordered.  However, it does
       * not contain a memory barrier, so if it is used for locking purposes,
       * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
       * in order to ensure changes are visible on other processors.
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      c524e494
    • Hugh Dickins's avatar
      [PATCH] rmaplock: swapoff use anon_vma · 69929041
      Hugh Dickins authored
      Swapoff can make good use of a page's anon_vma and index, while it's still
      left in swapcache, or once it's brought back in and the first pte mapped back:
      unuse_vma go directly to just one page of only those vmas with the same
      anon_vma.  And unuse_process can skip any vmas without an anon_vma (extending
      the hugetlb check: hugetlb vmas have no anon_vma).
      
      This just hacks in on top of the existing procedure, still going through all
      the vmas of all the mms in mmlist.  A more elegant procedure might replace
      mmlist by a list of anon_vmas: but that would be more work to implement, with
      apparently more overhead in the common paths.
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      69929041
    • Hugh Dickins's avatar
      [PATCH] rmaplock: mm lock ordering · 9d9ae43b
      Hugh Dickins authored
      With page_map_lock out of the way, there's no need for page_referenced and
      try_to_unmap to use trylocks - provided we switch anon_vma->lock and
      mm->page_table_lock around in anon_vma_prepare.  Though I suppose it's
      possible that we'll find that vmscan makes better progress with trylocks than
      spinning - we're free to choose trylocks again if so.
      
      Try to update the mm lock ordering documentation in filemap.c.  But I still
      find it confusing, and I've no idea of where to stop.  So add an mm lock
      ordering list I can understand to rmap.c.
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      9d9ae43b
    • Hugh Dickins's avatar
      [PATCH] rmaplock: SLAB_DESTROY_BY_RCU · 77631565
      Hugh Dickins authored
      With page_map_lock gone, how to stabilize page->mapping's anon_vma while
      acquiring anon_vma->lock in page_referenced_anon and try_to_unmap_anon?
      
      The page cannot actually be freed (vmscan holds reference), but however much
      we check page_mapped (which guarantees that anon_vma is in use - or would
      guarantee that if we added suitable barriers), there's no locking against page
      becoming unmapped the instant after, then anon_vma freed.
      
      It's okay to take anon_vma->lock after it's freed, so long as it remains a
      struct anon_vma (its list would become empty, or perhaps reused for an
      unrelated anon_vma: but no problem since we always check that the page located
      is the right one); but corruption if that memory gets reused for some other
      purpose.
      
      This is not unique: it's liable to be problem whenever the kernel tries to
      approach a structure obliquely.  It's generally solved with an atomic
      reference count; but one advantage of anon_vma over anonmm is that it does not
      have such a count, and it would be a backward step to add one.
      
      Therefore...  implement SLAB_DESTROY_BY_RCU flag, to guarantee that such a
      kmem_cache_alloc'ed structure cannot get freed to other use while the
      rcu_read_lock is held i.e.  preempt disabled; and use that for anon_vma.
      
      Fix concerns raised by Manfred: this flag is incompatible with poisoning and
      destructor, and kmem_cache_destroy needs to synchronize_kernel.
      
      I hope SLAB_DESTROY_BY_RCU may be useful elsewhere; but though it's safe for
      little anon_vma, I'd be reluctant to use it on any caches whose immediate
      shrinkage under pressure is important to the system.
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      77631565