1. 17 5月, 2008 1 次提交
  2. 13 5月, 2008 1 次提交
  3. 11 5月, 2008 1 次提交
    • L
      BKL: revert back to the old spinlock implementation · 8e3e076c
      Linus Torvalds 提交于
      The generic semaphore rewrite had a huge performance regression on AIM7
      (and potentially other BKL-heavy benchmarks) because the generic
      semaphores had been rewritten to be simple to understand and fair.  The
      latter, in particular, turns a semaphore-based BKL implementation into a
      mess of scheduling.
      
      The attempt to fix the performance regression failed miserably (see the
      previous commit 00b41ec2 'Revert
      "semaphore: fix"'), and so for now the simple and sane approach is to
      instead just go back to the old spinlock-based BKL implementation that
      never had any issues like this.
      
      This patch also has the advantage of being reported to fix the
      regression completely according to Yanmin Zhang, unlike the semaphore
      hack which still left a couple percentage point regression.
      
      As a spinlock, the BKL obviously has the potential to be a latency
      issue, but it's not really any different from any other spinlock in that
      respect.  We do want to get rid of the BKL asap, but that has been the
      plan for several years.
      
      These days, the biggest users are in the tty layer (open/release in
      particular) and Alan holds out some hope:
      
        "tty release is probably a few months away from getting cured - I'm
         afraid it will almost certainly be the very last user of the BKL in
         tty to get fixed as it depends on everything else being sanely locked."
      
      so while we're not there yet, we do have a plan of action.
      Tested-by: NYanmin Zhang <yanmin_zhang@linux.intel.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Matthew Wilcox <matthew@wil.cx>
      Cc: Alexander Viro <viro@ftp.linux.org.uk>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8e3e076c
  4. 04 5月, 2008 1 次提交
    • U
      unified (weak) sys_pipe implementation · d35c7b0e
      Ulrich Drepper 提交于
      This replaces the duplicated arch-specific versions of "sys_pipe()" with
      one unified implementation.  This removes almost 250 lines of duplicated
      code.
      
      It's marked __weak, so that *if* an architecture wants to override the
      default implementation it can do so by simply having its own replacement
      version, since many architectures use alternate calling conventions for
      the 'pipe()' system call for legacy reasons (ie traditional UNIX
      implementations often return the two file descriptors in registers)
      
      I still haven't changed the cris version even though Linus says the BKL
      isn't needed.  The arch maintainer can easily do it if there are really
      no obstacles.
      Signed-off-by: NUlrich Drepper <drepper@redhat.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d35c7b0e
  5. 29 4月, 2008 2 次提交
  6. 21 4月, 2008 1 次提交
    • G
      PCI: remove initial bios sort of PCI devices on x86 · 1ba6ab11
      Greg Kroah-Hartman 提交于
      We currently keep 2 lists of PCI devices in the system, one in the
      driver core, and one all on its own.  This second list is sorted at boot
      time, in "BIOS" order, to try to remain compatible with older kernels
      (2.2 and earlier days).  There was also a "nosort" option to turn this
      sorting off, to remain compatible with even older kernel versions, but
      that just ends up being what we have been doing from 2.5 days...
      
      Unfortunately, the second list of devices is not really ever used to 
      determine the probing order of PCI devices or drivers[1].  That is done
      using the driver core list instead.  This change happened back in the
      early 2.5 days.
      
      Relying on BIOS ording for the binding of drivers to specific device
      names is problematic for many reasons, and userspace tools like udev
      exist to properly name devices in a persistant manner if that is needed,
      no reliance on the BIOS is needed.
      
      Matt Domsch and others at Dell noticed this back in 2006, and added a
      boot option to sort the PCI device lists (both of them) in a
      breadth-first manner to help remain compatible with the 2.4 order, if
      needed for any reason.  This option is not going away, as some systems
      rely on them.
      
      This patch removes the sorting of the internal PCI device list in "BIOS"
      mode, as it's not needed at all anymore, and hasn't for many years.
      I've also removed the PCI flags for this from some other arches that for
      some reason defined them, but never used them.
      
      This should not change the ordering of any drivers or device probing.
      
      [1] The old-style pci_get_device and pci_find_device() still used this
      sorting order, but there are very few drivers that use these functions,
      as they are deprecated for use in this manner.  If for some reason, a
      driver rely on the order and uses these functions, the breadth-first
      boot option will resolve any problem.
      
      Cc: Matt Domsch <Matt_Domsch@dell.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      1ba6ab11
  7. 17 4月, 2008 1 次提交
  8. 24 2月, 2008 1 次提交
  9. 20 2月, 2008 4 次提交
  10. 09 2月, 2008 2 次提交
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