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  1. Mar 30, 2010
    • Tejun Heo's avatar
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo authored
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Guess-its-ok-by: default avatarChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  2. Feb 17, 2010
    • Breno Leitao's avatar
      powerpc/eeh: Fix a bug when pci structure is null · 8d3d50bf
      Breno Leitao authored
      
      
      During a EEH recover, the pci_dev structure can be null, mainly if an
      eeh event is detected during cpi config operation. In this case, the
      pci_dev will not be known (and will be null) the kernel will crash
      with the following message:
      
      Unable to handle kernel paging request for data at address 0x000000a0
      Faulting instruction address: 0xc00000000006b8b4
      Oops: Kernel access of bad area, sig: 11 [#1]
      
      NIP [c00000000006b8b4] .eeh_event_handler+0x10c/0x1a0
      LR [c00000000006b8a8] .eeh_event_handler+0x100/0x1a0
      Call Trace:
      [c0000003a80dff00] [c00000000006b8a8] .eeh_event_handler+0x100/0x1a0
      [c0000003a80dff90] [c000000000031f1c] .kernel_thread+0x54/0x70
      
      The bug occurs because pci_name() tries to access a null pointer.
      This patch just guarantee that pci_name() is not called on Null pointers.
      
      Signed-off-by: default avatarBreno Leitao <leitao@linux.vnet.ibm.com>
      Signed-off-by: default avatarLinas Vepstas <linasvepstas@gmail.com>
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      8d3d50bf
  3. Apr 12, 2007
  4. Mar 22, 2007
  5. Nov 22, 2006
  6. Jul 31, 2006
  7. Jun 28, 2006
  8. May 03, 2006
    • Linas Vepstas's avatar
      [PATCH] powerpc/pseries: avoid crash in PCI code if mem system not up · 054d8ff3
      Linas Vepstas authored
      
      
      The powerpc code is currently performing PCI setup before memory
      initialization.  PCI setup touches PCI config space registers.  If the PCI
      card is bad, this will evoke an error, which currrently can't be handled,
      as the PCI error recovery code expects kmalloc() to be functional.  This
      patch will cause the system to punt instead of crashing with
      
      cpu 0x0: Vector: 300 (Data Access) at [c0000000004434d0]
          pc: c0000000000c06b4: .kmem_cache_alloc+0x8c/0xf4
          lr: c00000000004ad6c: .eeh_send_failure_event+0x48/0xfc
      
      This patch will also print name of the offending pci device.
      
      Signed-off-by: default avatarLinas Vepstas <linas@austin.ibm.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      054d8ff3
  9. Apr 22, 2006
    • Linas Vepstas's avatar
      [PATCH] powerpc/pseries: clear PCI failure counter if no new failures · ac325acd
      Linas Vepstas authored
      
      
      The current PCI error recovery system keeps track of the number of PCI card
      resets, and refuses to bring a card back up if this number is too large.
      The goal of doing this was to avoid an infinite loop of resets if a card is
      obviously dead.  However, if the failures are rare, but the machine has a
      high uptime, this mechanism might still be triggered; this is too harsh.
      
      This patch will avoids this problem by decrementing the fail count after an
      hour.  Thus, as long as a pci card BSOD's less than 6 times an hour, it
      will continue to be reset indefinitely.  If it's failure rate is greater
      than that, it will be taken off-line permanently.
      
      This patch is larger than it might otherwise be because it changes
      indentation by removing a pointless while-loop.  The while loop is not
      needed, as the handler is invoked once fo each event (by schedule_work());
      the loop is leftover cruft from an earlier implementation.
      
      Signed-off-by: default avatarLinas Vepstas <linas@austin.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      ac325acd
  10. Apr 01, 2006
  11. Jan 10, 2006
  12. Nov 10, 2005
    • Linas Vepstas's avatar
      [PATCH] ppc64: PCI error event dispatcher · 172ca926
      Linas Vepstas authored
      
      
      12-eeh-event-dispatcher.patch
      
      ppc64: EEH Recovery dispatcher thread
      
      This patch adds a mechanism to create recovery threads when an
      EEH event is received.  Since an EEH freeze state may be detected
      within an interrupt context, we need to get out of the interrupt
      context before starting recovery. This dispatcher does this in
      two steps: first, it uses a workqueue to get out, and then
      lanuches a kernel thread, so that the recovery routine can
      sleep for exteded periods without upseting the keventd.
      
      A kernel thread is created with each EEH event, rather than
      having one long-running daemon started at boot time.  This is
      because it is anticipated that EEH events will be very rare
      (very very rare, ideally) and so its pointless to cluter the
      process tables with a daemon that will almost never run.
      
      Signed-off-by: default avatarLinas Vepstas <linas@austin.ibm.com>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      172ca926
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