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  1. 13 5月, 2006 1 次提交
  3. 04 5月, 2006 1 次提交
  5. 01 5月, 2006 1 次提交
  7. 20 4月, 2006 1 次提交
  9. 18 4月, 2006 1 次提交
  11. 15 4月, 2006 1 次提交
  13. 11 4月, 2006 2 次提交
  15. 10 4月, 2006 4 次提交
  17. 01 4月, 2006 3 次提交
  19. 29 3月, 2006 1 次提交
  21. 28 3月, 2006 1 次提交
    • A
      [PATCH] Notifier chain update: API changes · e041c683
      由 Alan Stern 提交于 
      The kernel's implementation of notifier chains is unsafe.  There is no
protection against entries being added to or removed from a chain while the
chain is in use.  The issues were discussed in this thread:

    http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2

We noticed that notifier chains in the kernel fall into two basic usage
classes:

	"Blocking" chains are always called from a process context
	and the callout routines are allowed to sleep;

	"Atomic" chains can be called from an atomic context and
	the callout routines are not allowed to sleep.

We decided to codify this distinction and make it part of the API.  Therefore
this set of patches introduces three new, parallel APIs: one for blocking
notifiers, one for atomic notifiers, and one for "raw" notifiers (which is
really just the old API under a new name).  New kinds of data structures are
used for the heads of the chains, and new routines are defined for
registration, unregistration, and calling a chain.  The three APIs are
explained in include/linux/notifier.h and their implementation is in
kernel/sys.c.

With atomic and blocking chains, the implementation guarantees that the chain
links will not be corrupted and that chain callers will not get messed up by
entries being added or removed.  For raw chains the implementation provides no
guarantees at all; users of this API must provide their own protections.  (The
idea was that situations may come up where the assumptions of the atomic and
blocking APIs are not appropriate, so it should be possible for users to
handle these things in their own way.)

There are some limitations, which should not be too hard to live with.  For
atomic/blocking chains, registration and unregistration must always be done in
a process context since the chain is protected by a mutex/rwsem.  Also, a
callout routine for a non-raw chain must not try to register or unregister
entries on its own chain.  (This did happen in a couple of places and the code
had to be changed to avoid it.)

Since atomic chains may be called from within an NMI handler, they cannot use
spinlocks for synchronization.  Instead we use RCU.  The overhead falls almost
entirely in the unregister routine, which is okay since unregistration is much
less frequent that calling a chain.

Here is the list of chains that we adjusted and their classifications.  None
of them use the raw API, so for the moment it is only a placeholder.

  ATOMIC CHAINS
  -------------
arch/i386/kernel/traps.c:		i386die_chain
arch/ia64/kernel/traps.c:		ia64die_chain
arch/powerpc/kernel/traps.c:		powerpc_die_chain
arch/sparc64/kernel/traps.c:		sparc64die_chain
arch/x86_64/kernel/traps.c:		die_chain
drivers/char/ipmi/ipmi_si_intf.c:	xaction_notifier_list
kernel/panic.c:				panic_notifier_list
kernel/profile.c:			task_free_notifier
net/bluetooth/hci_core.c:		hci_notifier
net/ipv4/netfilter/ip_conntrack_core.c:	ip_conntrack_chain
net/ipv4/netfilter/ip_conntrack_core.c:	ip_conntrack_expect_chain
net/ipv6/addrconf.c:			inet6addr_chain
net/netfilter/nf_conntrack_core.c:	nf_conntrack_chain
net/netfilter/nf_conntrack_core.c:	nf_conntrack_expect_chain
net/netlink/af_netlink.c:		netlink_chain

  BLOCKING CHAINS
  ---------------
arch/powerpc/platforms/pseries/reconfig.c:	pSeries_reconfig_chain
arch/s390/kernel/process.c:		idle_chain
arch/x86_64/kernel/process.c		idle_notifier
drivers/base/memory.c:			memory_chain
drivers/cpufreq/cpufreq.c		cpufreq_policy_notifier_list
drivers/cpufreq/cpufreq.c		cpufreq_transition_notifier_list
drivers/macintosh/adb.c:		adb_client_list
drivers/macintosh/via-pmu.c		sleep_notifier_list
drivers/macintosh/via-pmu68k.c		sleep_notifier_list
drivers/macintosh/windfarm_core.c	wf_client_list
drivers/usb/core/notify.c		usb_notifier_list
drivers/video/fbmem.c			fb_notifier_list
kernel/cpu.c				cpu_chain
kernel/module.c				module_notify_list
kernel/profile.c			munmap_notifier
kernel/profile.c			task_exit_notifier
kernel/sys.c				reboot_notifier_list
net/core/dev.c				netdev_chain
net/decnet/dn_dev.c:			dnaddr_chain
net/ipv4/devinet.c:			inetaddr_chain

It's possible that some of these classifications are wrong.  If they are,
please let us know or submit a patch to fix them.  Note that any chain that
gets called very frequently should be atomic, because the rwsem read-locking
used for blocking chains is very likely to incur cache misses on SMP systems.
(However, if the chain's callout routines may sleep then the chain cannot be
atomic.)

The patch set was written by Alan Stern and Chandra Seetharaman, incorporating
material written by Keith Owens and suggestions from Paul McKenney and Andrew
Morton.

[jes@sgi.com: restructure the notifier chain initialization macros]
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJes Sorensen <jes@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      e041c683
  23. 27 3月, 2006 6 次提交
  25. 26 3月, 2006 1 次提交
  27. 24 3月, 2006 1 次提交
  29. 23 3月, 2006 1 次提交
    • A
      [PATCH] more for_each_cpu() conversions · 394e3902
      由 Andrew Morton 提交于 
      When we stop allocating percpu memory for not-possible CPUs we must not touch
the percpu data for not-possible CPUs at all.  The correct way of doing this
is to test cpu_possible() or to use for_each_cpu().

This patch is a kernel-wide sweep of all instances of NR_CPUS.  I found very
few instances of this bug, if any.  But the patch converts lots of open-coded
test to use the preferred helper macros.

Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Acked-by: NKyle McMartin <kyle@parisc-linux.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Christian Zankel <chris@zankel.net>
Cc: Philippe Elie <phil.el@wanadoo.fr>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Jens Axboe <axboe@suse.de>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      394e3902
  31. 22 3月, 2006 2 次提交
  33. 20 3月, 2006 12 次提交
    • A
      [SPARC64]: CONFIG_BLK_DEV_RAM fix · 467418f3
      由 Andrew Morton 提交于 
      init/do_mounts_rd.c depends upon CONFIG_BLK_DEV_RAM, not CONFIG_BLK_DEV_INITRD.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      467418f3
    • D
      [SPARC64]: Optimized TSB table initialization. · bb8646d8
      由 David S. Miller 提交于 
      We only need to write an invalid tag every 16 bytes,
so taking advantage of this can save many instructions
compared to the simple memset() call we make now.

A prefetching implementation is implemented for sun4u
and a block-init store version if implemented for Niagara.

The next trick is to be able to perform an init and
a copy_tsb() in parallel when growing a TSB table.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      bb8646d8
    • D
      [SPARC64]: Randomize mm->mmap_base when PF_RANDOMIZE is set. · 05f9ca83
      由 David S. Miller 提交于 
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      05f9ca83
    • D
      [SPARC64]: Increase top of 32-bit process stack. · d61e16df
      由 David S. Miller 提交于 
      Put it one page below the top of the 32-bit address space.
This gives us ~16MB more address space to work with.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d61e16df
    • D
      [SPARC64]: Top-down address space allocation for 32-bit tasks. · a91690dd
      由 David S. Miller 提交于 
      Currently allocations are very constrained for 32-bit processes.
It grows down-up from 0x70000000 to 0xf0000000 which gives about
2GB of stack + dynamic mmap() space.

So support the top-down method, and we need to override the
generic helper function in order to deal with D-cache coloring.

With these changes I was able to squeeze out a mmap() just over
3.6GB in size in a 32-bit process.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a91690dd
    • D
      [SPARC64]: Fix and re-enable dynamic TSB sizing. · 7a1ac526
      由 David S. Miller 提交于 
      This is good for up to %50 performance improvement of some test cases.
The problem has been the race conditions, and hopefully I've plugged
them all up here.

1) There was a serious race in switch_mm() wrt. lazy TLB
   switching to and from kernel threads.

   We could erroneously skip a tsb_context_switch() and thus
   use a stale TSB across a TSB grow event.

   There is a big comment now in that function describing
   exactly how it can happen.

2) All code paths that do something with the TSB need to be
   guarded with the mm->context.lock spinlock.  This makes
   page table flushing paths properly synchronize with both
   TSB growing and TLB context changes.

3) TSB growing events are moved to the end of successful fault
   processing.  Previously it was in update_mmu_cache() but
   that is deadlock prone.  At the end of do_sparc64_fault()
   we hold no spinlocks that could deadlock the TSB grow
   sequence.  We also have dropped the address space semaphore.

While we're here, add prefetching to the copy_tsb() routine
and put it in assembler into the tsb.S file.  This piece of
code is quite time critical.

There are some small negative side effects to this code which
can be improved upon.  In particular we grab the mm->context.lock
even for the tsb insert done by update_mmu_cache() now and that's
a bit excessive.  We can get rid of that locking, and the same
lock taking in flush_tsb_user(), by disabling PSTATE_IE around
the whole operation including the capturing of the tsb pointer
and tsb_nentries value.  That would work because anyone growing
the TSB won't free up the old TSB until all cpus respond to the
TSB change cross call.

I'm not quite so confident in that optimization to put it in
right now, but eventually we might be able to and the description
is here for reference.

This code seems very solid now.  It passes several parallel GCC
bootstrap builds, and our favorite "nut cruncher" stress test which is
a full "make -j8192" build of a "make allmodconfig" kernel.  That puts
about 256 processes on each cpu's run queue, makes lots of process cpu
migrations occur, causes lots of page table and TLB flushing activity,
incurs many context version number changes, and it swaps the machine
real far out to disk even though there is 16GB of ram on this test
system. :-)
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7a1ac526
    • D
      [SPARC64]: First cut at VIS simulator for Niagara. · 0c51ed93
      由 David S. Miller 提交于 
      Niagara does not implement some of the VIS instructions in
hardware, so we have to emulate them.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      0c51ed93
    • D
      [SPARC64]: Fix system type in /proc/cpuinfo and remove bogus OBP check. · 90a6646b
      由 David S. Miller 提交于 
      Report 'sun4v' when appropriate in /proc/cpuinfo

Remove all the verifications of the OBP version string.  Just
make sure it's there, and report it raw in the bootup logs and
via /proc/cpuinfo.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      90a6646b
    • D
      [SPARC64]: Add SMT scheduling support for Niagara. · 8935dced
      由 David S. Miller 提交于 
      The mapping is a simple "(cpuid >> 2) == core" for now.
Later we'll add more sophisticated code that will walk
the sun4v machine description and figure this out from
there.

We should also add core mappings for jaguar and panther
processors.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      8935dced
    • D
      [SPARC64]: Move over to sparsemem. · d1112018
      由 David S. Miller 提交于 
      This has been pending for a long time, and the fact
that we waste a ton of ram on some configurations
kind of pushed things over the edge.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d1112018
    • D
      [SPARC64]: Fix new context version SMP handling. · ee29074d
      由 David S. Miller 提交于 
      Don't piggy back the SMP receive signal code to do the
context version change handling.

Instead allocate another fixed PIL number for this
asynchronous cross-call.  We can't use smp_call_function()
because this thing is invoked with interrupts disabled
and a few spinlocks held.

Also, fix smp_call_function_mask() to count "cpus" correctly.
There is no guarentee that the local cpu is in the mask
yet that is exactly what this code was assuming.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      ee29074d
    • E
      [SPARC64]: kzalloc() conversion · 9132983a
      由 Eric Sesterhenn 提交于 
      this patch converts arch/sparc64 to kzalloc usage.
Crosscompile tested with allyesconfig.
Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9132983a