1. 22 10月, 2010 1 次提交
    • A
      x86, kexec: Make sure to stop all CPUs before exiting the kernel · 76fac077
      Alok Kataria 提交于
      x86 smp_ops now has a new op, stop_other_cpus which takes a parameter
      "wait" this allows the caller to specify if it wants to stop until all
      the cpus have processed the stop IPI.  This is required specifically
      for the kexec case where we should wait for all the cpus to be stopped
      before starting the new kernel.  We now wait for the cpus to stop in
      all cases except for panic/kdump where we expect things to be broken
      and we are doing our best to make things work anyway.
      
      This patch fixes a legitimate regression, which was introduced during
      2.6.30, by commit id 4ef702c1.
      Signed-off-by: NAlok N Kataria <akataria@vmware.com>
      LKML-Reference: <1286833028.1372.20.camel@ank32.eng.vmware.com>
      Cc: Eric W. Biederman <ebiederm@xmission.com>
      Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
      Cc: <stable@kernel.org> v2.6.30-36
      Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      76fac077
  2. 05 8月, 2010 1 次提交
  3. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      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: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  4. 05 2月, 2010 1 次提交
  5. 04 12月, 2009 1 次提交
  6. 04 11月, 2009 1 次提交
  7. 29 10月, 2009 1 次提交
    • T
      percpu: make percpu symbols in xen unique · c6e22f9e
      Tejun Heo 提交于
      This patch updates percpu related symbols in xen such that percpu
      symbols are unique and don't clash with local symbols.  This serves
      two purposes of decreasing the possibility of global percpu symbol
      collision and allowing dropping per_cpu__ prefix from percpu symbols.
      
      * arch/x86/xen/smp.c, arch/x86/xen/time.c, arch/ia64/xen/irq_xen.c:
        add xen_ prefix to percpu variables
      
      * arch/ia64/xen/time.c: add xen_ prefix to percpu variables, drop
        processed_ prefix and make them static
      
      Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
      which cause name clashes" patch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
      Cc: Chris Wright <chrisw@sous-sol.org>
      c6e22f9e
  8. 10 9月, 2009 1 次提交
    • J
      xen: make -fstack-protector work under Xen · 577eebea
      Jeremy Fitzhardinge 提交于
      -fstack-protector uses a special per-cpu "stack canary" value.
      gcc generates special code in each function to test the canary to make
      sure that the function's stack hasn't been overrun.
      
      On x86-64, this is simply an offset of %gs, which is the usual per-cpu
      base segment register, so setting it up simply requires loading %gs's
      base as normal.
      
      On i386, the stack protector segment is %gs (rather than the usual kernel
      percpu %fs segment register).  This requires setting up the full kernel
      GDT and then loading %gs accordingly.  We also need to make sure %gs is
      initialized when bringing up secondary cpus too.
      
      To keep things consistent, we do the full GDT/segment register setup on
      both architectures.
      
      Because we need to avoid -fstack-protected code before setting up the GDT
      and because there's no way to disable it on a per-function basis, several
      files need to have stack-protector inhibited.
      
      [ Impact: allow Xen booting with stack-protector enabled ]
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      577eebea
  9. 09 4月, 2009 1 次提交
  10. 31 3月, 2009 1 次提交
  11. 13 3月, 2009 1 次提交
  12. 02 3月, 2009 1 次提交
    • J
      xen: deal with virtually mapped percpu data · 9976b39b
      Jeremy Fitzhardinge 提交于
      The virtually mapped percpu space causes us two problems:
      
       - for hypercalls which take an mfn, we need to do a full pagetable
         walk to convert the percpu va into an mfn, and
      
       - when a hypercall requires a page to be mapped RO via all its aliases,
         we need to make sure its RO in both the percpu mapping and in the
         linear mapping
      
      This primarily affects the gdt and the vcpu info structure.
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      Cc: Xen-devel <xen-devel@lists.xensource.com>
      Cc: Gerd Hoffmann <kraxel@redhat.com>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Tejun Heo <htejun@gmail.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      9976b39b
  13. 05 2月, 2009 1 次提交
  14. 31 1月, 2009 1 次提交
  15. 27 1月, 2009 1 次提交
  16. 18 1月, 2009 2 次提交
  17. 16 1月, 2009 2 次提交
    • I
      percpu: add optimized generic percpu accessors · 6dbde353
      Ingo Molnar 提交于
      It is an optimization and a cleanup, and adds the following new
      generic percpu methods:
      
        percpu_read()
        percpu_write()
        percpu_add()
        percpu_sub()
        percpu_and()
        percpu_or()
        percpu_xor()
      
      and implements support for them on x86. (other architectures will fall
      back to a default implementation)
      
      The advantage is that for example to read a local percpu variable,
      instead of this sequence:
      
       return __get_cpu_var(var);
      
       ffffffff8102ca2b:	48 8b 14 fd 80 09 74 	mov    -0x7e8bf680(,%rdi,8),%rdx
       ffffffff8102ca32:	81
       ffffffff8102ca33:	48 c7 c0 d8 59 00 00 	mov    $0x59d8,%rax
       ffffffff8102ca3a:	48 8b 04 10          	mov    (%rax,%rdx,1),%rax
      
      We can get a single instruction by using the optimized variants:
      
       return percpu_read(var);
      
       ffffffff8102ca3f:	65 48 8b 05 91 8f fd 	mov    %gs:0x7efd8f91(%rip),%rax
      
      I also cleaned up the x86-specific APIs and made the x86 code use
      these new generic percpu primitives.
      
      tj: * fixed generic percpu_sub() definition as Roel Kluin pointed out
          * added percpu_and() for completeness's sake
          * made generic percpu ops atomic against preemption
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      Signed-off-by: NTejun Heo <tj@kernel.org>
      6dbde353
    • T
      x86: fold pda into percpu area on SMP · 1a51e3a0
      Tejun Heo 提交于
      [ Based on original patch from Christoph Lameter and Mike Travis. ]
      
      Currently pdas and percpu areas are allocated separately.  %gs points
      to local pda and percpu area can be reached using pda->data_offset.
      This patch folds pda into percpu area.
      
      Due to strange gcc requirement, pda needs to be at the beginning of
      the percpu area so that pda->stack_canary is at %gs:40.  To achieve
      this, a new percpu output section macro - PERCPU_VADDR_PREALLOC() - is
      added and used to reserve pda sized chunk at the start of the percpu
      area.
      
      After this change, for boot cpu, %gs first points to pda in the
      data.init area and later during setup_per_cpu_areas() gets updated to
      point to the actual pda.  This means that setup_per_cpu_areas() need
      to reload %gs for CPU0 while clearing pda area for other cpus as cpu0
      already has modified it when control reaches setup_per_cpu_areas().
      
      This patch also removes now unnecessary get_local_pda() and its call
      sites.
      
      A lot of this patch is taken from Mike Travis' "x86_64: Fold pda into
      per cpu area" patch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      1a51e3a0
  18. 17 12月, 2008 3 次提交
  19. 01 12月, 2008 1 次提交
  20. 09 9月, 2008 2 次提交
  21. 25 8月, 2008 1 次提交
    • A
      xen: implement CPU hotplugging · d68d82af
      Alex Nixon 提交于
      Note the changes from 2.6.18-xen CPU hotplugging:
      
      A vcpu_down request from the remote admin via Xenbus both hotunplugs the
      CPU, and disables it by removing it from the cpu_present map, and removing
      its entry in /sys.
      
      A vcpu_up request from the remote admin only re-enables the CPU, and does
      not immediately bring the CPU up. A udev event is emitted, which can be
      caught by the user if he wishes to automatically re-up CPUs when available,
      or implement a more complex policy.
      Signed-off-by: NAlex Nixon <alex.nixon@citrix.com>
      Acked-by: NJeremy Fitzhardinge <jeremy@goop.org>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      d68d82af
  22. 24 7月, 2008 1 次提交
  23. 16 7月, 2008 6 次提交
    • J
      xen: implement Xen-specific spinlocks · 2d9e1e2f
      Jeremy Fitzhardinge 提交于
      The standard ticket spinlocks are very expensive in a virtual
      environment, because their performance depends on Xen's scheduler
      giving vcpus time in the order that they're supposed to take the
      spinlock.
      
      This implements a Xen-specific spinlock, which should be much more
      efficient.
      
      The fast-path is essentially the old Linux-x86 locks, using a single
      lock byte.  The locker decrements the byte; if the result is 0, then
      they have the lock.  If the lock is negative, then locker must spin
      until the lock is positive again.
      
      When there's contention, the locker spin for 2^16[*] iterations waiting
      to get the lock.  If it fails to get the lock in that time, it adds
      itself to the contention count in the lock and blocks on a per-cpu
      event channel.
      
      When unlocking the spinlock, the locker looks to see if there's anyone
      blocked waiting for the lock by checking for a non-zero waiter count.
      If there's a waiter, it traverses the per-cpu "lock_spinners"
      variable, which contains which lock each CPU is waiting on.  It picks
      one CPU waiting on the lock and sends it an event to wake it up.
      
      This allows efficient fast-path spinlock operation, while allowing
      spinning vcpus to give up their processor time while waiting for a
      contended lock.
      
      [*] 2^16 iterations is threshold at which 98% locks have been taken
      according to Thomas Friebel's Xen Summit talk "Preventing Guests from
      Spinning Around".  Therefore, we'd expect the lock and unlock slow
      paths will only be entered 2% of the time.
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Christoph Lameter <clameter@linux-foundation.org>
      Cc: Petr Tesarik <ptesarik@suse.cz>
      Cc: Virtualization <virtualization@lists.linux-foundation.org>
      Cc: Xen devel <xen-devel@lists.xensource.com>
      Cc: Thomas Friebel <thomas.friebel@amd.com>
      Cc: Nick Piggin <nickpiggin@yahoo.com.au>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      2d9e1e2f
    • J
      xen: use lock-byte spinlock implementation · 56397f8d
      Jeremy Fitzhardinge 提交于
      Switch to using the lock-byte spinlock implementation, to avoid the
      worst of the performance hit from ticket locks.
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Christoph Lameter <clameter@linux-foundation.org>
      Cc: Petr Tesarik <ptesarik@suse.cz>
      Cc: Virtualization <virtualization@lists.linux-foundation.org>
      Cc: Xen devel <xen-devel@lists.xensource.com>
      Cc: Thomas Friebel <thomas.friebel@amd.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      56397f8d
    • J
      xen64: set up syscall and sysenter entrypoints for 64-bit · 6fcac6d3
      Jeremy Fitzhardinge 提交于
      We set up entrypoints for syscall and sysenter.  sysenter is only used
      for 32-bit compat processes, whereas syscall can be used in by both 32
      and 64-bit processes.
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      Cc: Stephen Tweedie <sct@redhat.com>
      Cc: Eduardo Habkost <ehabkost@redhat.com>
      Cc: Mark McLoughlin <markmc@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      6fcac6d3
    • J
      xen: set num_processors · 4560a294
      Jeremy Fitzhardinge 提交于
      Someone's got to do it.
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      Cc: Stephen Tweedie <sct@redhat.com>
      Cc: Eduardo Habkost <ehabkost@redhat.com>
      Cc: Mark McLoughlin <markmc@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      4560a294
    • J
      xen64: smp.c compile hacking · c7b75947
      Jeremy Fitzhardinge 提交于
      A number of random changes to make xen/smp.c compile in 64-bit mode.
      
      Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>a
      Cc: Stephen Tweedie <sct@redhat.com>
      Cc: Eduardo Habkost <ehabkost@redhat.com>
      Cc: Mark McLoughlin <markmc@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      c7b75947
    • J
      xen: move smp setup into smp.c · a9e7062d
      Jeremy Fitzhardinge 提交于
      Move all the smp_ops setup into smp.c, allowing a lot of things to
      become static.
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      Cc: Stephen Tweedie <sct@redhat.com>
      Cc: Eduardo Habkost <ehabkost@redhat.com>
      Cc: Mark McLoughlin <markmc@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      a9e7062d
  24. 26 6月, 2008 2 次提交
  25. 27 5月, 2008 2 次提交
    • J
      xen: implement save/restore · 0e91398f
      Jeremy Fitzhardinge 提交于
      This patch implements Xen save/restore and migration.
      
      Saving is triggered via xenbus, which is polled in
      drivers/xen/manage.c.  When a suspend request comes in, the kernel
      prepares itself for saving by:
      
      1 - Freeze all processes.  This is primarily to prevent any
          partially-completed pagetable updates from confusing the suspend
          process.  If CONFIG_PREEMPT isn't defined, then this isn't necessary.
      
      2 - Suspend xenbus and other devices
      
      3 - Stop_machine, to make sure all the other vcpus are quiescent.  The
          Xen tools require the domain to run its save off vcpu0.
      
      4 - Within the stop_machine state, it pins any unpinned pgds (under
          construction or destruction), performs canonicalizes various other
          pieces of state (mostly converting mfns to pfns), and finally
      
      5 - Suspend the domain
      
      Restore reverses the steps used to save the domain, ending when all
      the frozen processes are thawed.
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      0e91398f
    • J
      xen: count resched interrupts properly · 38bb5ab4
      Jeremy Fitzhardinge 提交于
      Make sure resched interrupts appear in /proc/interrupts in the proper
      place.
      Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      38bb5ab4
  26. 24 5月, 2008 1 次提交
  27. 26 4月, 2008 1 次提交
  28. 25 4月, 2008 1 次提交