Commit graph

35784 commits

Author SHA1 Message Date
Christoph Lameter e53ef38d05 [PATCH] reduce MAX_NR_ZONES: make ZONE_HIGHMEM optional
Make ZONE_HIGHMEM optional

- ifdef out code and definitions related to CONFIG_HIGHMEM

- __GFP_HIGHMEM falls back to normal allocations if there is no
  ZONE_HIGHMEM

- GFP_ZONEMASK becomes 0x01 if there is no DMA32 and no HIGHMEM
  zone.

[jdike@addtoit.com: build fix]
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:46 -07:00
Christoph Lameter fb0e7942bd [PATCH] reduce MAX_NR_ZONES: make ZONE_DMA32 optional
Make ZONE_DMA32 optional

- Add #ifdefs around ZONE_DMA32 specific code and definitions.

- Add CONFIG_ZONE_DMA32 config option and use that for x86_64
  that alone needs this zone.

- Remove the use of CONFIG_DMA_IS_DMA32 and CONFIG_DMA_IS_NORMAL
  for ia64 and fix up the way per node ZVCs are calculated.

- Fall back to prior GFP_ZONEMASK of 0x03 if there is no
  DMA32 zone.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:46 -07:00
Christoph Lameter 2f1b624868 [PATCH] reduce MAX_NR_ZONES: use enum to define zones, reformat and comment
Use enum for zones and reformat zones dependent information

Add comments explaning the use of zones and add a zones_t type for zone
numbers.

Line up information that will be #ifdefd by the following patches.

[akpm@osdl.org: comment cleanups]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:46 -07:00
Christoph Lameter 98d2b0ebda [PATCH] reduce MAX_NR_ZONES: page allocator ZONE_HIGHMEM cleanup
page allocator ZONE_HIGHMEM fixups

1. We do not need to do an #ifdef in si_meminfo since both counters
   in use are zero if !CONFIG_HIGHMEM.

2. Add #ifdef in si_meminfo_node instead to avoid referencing zone
   information for ZONE_HIGHMEM if we do not have HIGHMEM
   (may not be there after the following patches).

3. Replace the use of ZONE_HIGHMEM with MAX_NR_ZONES in build_zonelists_node

4. build_zonelists_node: Remove BUG_ON for ZONE_HIGHMEM. Zone will
   be optional soon and thus BUG_ON cannot be triggered anymore.

5. init_free_area_core: Replace a use of ZONE_HIGHMEM with NR_MAX_ZONES.

[akpm@osdl.org: cleanups]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:46 -07:00
Christoph Lameter c1f60a5a41 [PATCH] reduce MAX_NR_ZONES: move HIGHMEM counters into highmem.c/.h
Move totalhigh_pages and nr_free_highpages() into highmem.c/.h

Move the totalhigh_pages definition into highmem.c/.h.  Move the
nr_free_highpages function into highmem.c

[yoichi_yuasa@tripeaks.co.jp: build fix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:46 -07:00
Christoph Lameter 182e8e2373 [PATCH] reduce MAX_NR_ZONES: make display of highmem counters conditional on CONFIG_HIGHMEM
Do not display HIGHMEM memory sizes if CONFIG_HIGHMEM is not set.

Make HIGHMEM dependent texts and make display of highmem counters optional

Some texts are depending on CONFIG_HIGHMEM.

Remove those strings and remove the display of highmem counter values if
CONFIG_HIGHMEM is not set.

[akpm@osdl.org: remove some ifdefs]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:46 -07:00
Christoph Lameter f06a96844a [PATCH] reduce MAX_NR_ZONES: fix MAX_NR_ZONES array initializations
Fix array initialization in lots of arches

The number of zones may now be reduced from 4 to 2 for many arches.  Fix the
array initialization for the zones array for all architectures so that it is
not initializing a fixed number of elements.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:46 -07:00
Christoph Lameter 776ed98b84 [PATCH] reduce MAX_NR_ZONES: remove two strange uses of MAX_NR_ZONES
I keep seeing zones on various platforms that are never used and wonder why we
compile support for them into the kernel.  Counters show up for HIGHMEM and
DMA32 that are alway zero.

This patch allows the removal of ZONE_DMA32 for non x86_64 architectures and
it will get rid of ZONE_HIGHMEM for arches not using highmem (like 64 bit
architectures).  If an arch does not define CONFIG_HIGHMEM then ZONE_HIGHMEM
will not be defined.  Similarly if an arch does not define CONFIG_ZONE_DMA32
then ZONE_DMA32 will not be defined.

No current architecture uses all the 4 zones (DMA,DMA32,NORMAL,HIGH) that we
have now.  The patchset will reduce the number of zones for all platforms.

On many platforms that do not have DMA32 or HIGHMEM this will reduce the
number of zones by 50%.  F.e.  ia64 only uses DMA and NORMAL.

Large amounts of memory can be saved for larger systemss that may have a few
hundred NUMA nodes.

With ZONE_DMA32 and ZONE_HIGHMEM support optional MAX_NR_ZONES will be 2 for
many non i386 platforms and even for i386 without CONFIG_HIGHMEM set.

Tested on ia64, x86_64 and on i386 with and without highmem.

The patchset consists of 11 patches that are following this message.

One could go even further than this patchset and also make ZONE_DMA optional
because some platforms do not need a separate DMA zone and can do DMA to all
of memory.  This could reduce MAX_NR_ZONES to 1.  Such a patchset will
hopefully follow soon.

This patch:

Fix strange uses of MAX_NR_ZONES

Sometimes we use MAX_NR_ZONES - x to refer to a zone.  Make that explicit.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:46 -07:00
Franck Bui-Huu f71bf0cac7 [PATCH] bootmem: miscellaneous coding style fixes
It fixes various coding style issues, specially when spaces are useless.  For
example '*' go next to the function name.

Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:45 -07:00
Franck Bui-Huu bbc7b92e33 [PATCH] bootmem: use pfn/page conversion macros
It also creates get_mapsize() helper in order to make the code more readable
when it calculates the boot bitmap size.

Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:45 -07:00
Franck Bui-Huu e786e86a54 [PATCH] bootmem: remove useless headers inclusions
Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:45 -07:00
Franck Bui-Huu bb0923a668 [PATCH] bootmem: limit to 80 columns width
Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:45 -07:00
Franck Bui-Huu 71fb2e8f87 [PATCH] bootmem: remove useless parentheses in bootmem header file
Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:45 -07:00
Franck Bui-Huu 69d49e681d [PATCH] bootmem: mark link_bootmem() as part of the __init section
Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:45 -07:00
Franck Bui-Huu 2d1a07d487 [PATCH] bootmem: remove useless __init in header file
__init in headers is pretty useless because the compiler doesn't check it, and
they get out of sync relatively frequently.  So if you see an __init in a
header file, it's quite unreliable and you need to check the definition
anyway.

Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:45 -07:00
keith mannthey 9102330005 [PATCH] convert i386 NUMA KVA space to bootmem
Address a long standing issue of booting with an initrd on an i386 numa
system.  Currently (and always) the numa kva area is mapped into low memory
by finding the end of low memory and moving that mark down (thus creating
space for the kva).  The issue with this is that Grub loads initrds into
this similar space so when the kernel check the initrd it finds it outside
max_low_pfn and disables it (it thinks the initrd is not mapped into usable
memory) thus initrd enabled kernels can't boot i386 numa :(

My solution to the problem just converts the numa kva area to use the
bootmem allocator to save it's area (instead of moving the end of low
memory).  Using bootmem allows the kva area to be mapped into more diverse
addresses (not just the end of low memory) and enables the kva area to be
mapped below the initrd if present.

I have tested this patch on numaq(no initrd) and summit(initrd) i386 numa
based systems.

[akpm@osdl.org: cleanups]
Signed-off-by: Keith Mannthey <kmannth@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:45 -07:00
Adrian Bunk b221385bc4 [PATCH] mm/: make functions static
This patch makes the following needlessly global functions static:
 - slab.c: kmem_find_general_cachep()
 - swap.c: __page_cache_release()
 - vmalloc.c: __vmalloc_node()

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:45 -07:00
Peter Zijlstra 204ec841fb [PATCH] mm: msync() cleanup
With the tracking of dirty pages properly done now, msync doesn't need to scan
the PTEs anymore to determine the dirty status.

From: Hugh Dickins <hugh@veritas.com>

In looking to do that, I made some other tidyups: can remove several
#includes, and sys_msync loop termination not quite right.

Most of those points are criticisms of the existing sys_msync, not of your
patch.  In particular, the loop termination errors were introduced in 2.6.17:
I did notice this shortly before it came out, but decided I was more likely to
get it wrong myself, and make matters worse if I tried to rush a last-minute
fix in.  And it's not terribly likely to go wrong, nor disastrous if it does
go wrong (may miss reporting an unmapped area; may also fsync file of a
following vma).

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:45 -07:00
Peter Zijlstra ee6a645788 [PATCH] mm: fixup do_wp_page()
Wrt. the recent modifications in do_wp_page() Hugh Dickins pointed out:

  "I now realize it's right to the first order (normal case) and to the
   second order (ptrace poke), but not to the third order (ptrace poke
   anon page here to be COWed - perhaps can't occur without intervening
   mprotects)."

This patch restores the old COW behaviour for anonymous pages.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:44 -07:00
Peter Zijlstra e88dd6c11c [PATCH] mm: small cleanup of install_page()
Smallish cleanup to install_page(), could save a memory read (haven't checked
the asm output) and sure looks nicer.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:44 -07:00
Peter Zijlstra c1e6098b23 [PATCH] mm: optimize the new mprotect() code a bit
mprotect() resets the page protections, which could result in extra write
faults for those pages whose dirty state we track using write faults and are
dirty already.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:44 -07:00
Peter Zijlstra edc79b2a46 [PATCH] mm: balance dirty pages
Now that we can detect writers of shared mappings, throttle them.  Avoids OOM
by surprise.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:44 -07:00
Peter Zijlstra d08b3851da [PATCH] mm: tracking shared dirty pages
Tracking of dirty pages in shared writeable mmap()s.

The idea is simple: write protect clean shared writeable pages, catch the
write-fault, make writeable and set dirty.  On page write-back clean all the
PTE dirty bits and write protect them once again.

The implementation is a tad harder, mainly because the default
backing_dev_info capabilities were too loosely maintained.  Hence it is not
enough to test the backing_dev_info for cap_account_dirty.

The current heuristic is as follows, a VMA is eligible when:
 - its shared writeable
    (vm_flags & (VM_WRITE|VM_SHARED)) == (VM_WRITE|VM_SHARED)
 - it is not a 'special' mapping
    (vm_flags & (VM_PFNMAP|VM_INSERTPAGE)) == 0
 - the backing_dev_info is cap_account_dirty
    mapping_cap_account_dirty(vma->vm_file->f_mapping)
 - f_op->mmap() didn't change the default page protection

Page from remap_pfn_range() are explicitly excluded because their COW
semantics are already horrid enough (see vm_normal_page() in do_wp_page()) and
because they don't have a backing store anyway.

mprotect() is taught about the new behaviour as well.  However it overrides
the last condition.

Cleaning the pages on write-back is done with page_mkclean() a new rmap call.
It can be called on any page, but is currently only implemented for mapped
pages, if the page is found the be of a VMA that accounts dirty pages it will
also wrprotect the PTE.

Finally, in fs/buffers.c:try_to_free_buffers(); remove clear_page_dirty() from
under ->private_lock.  This seems to be safe, since ->private_lock is used to
serialize access to the buffers, not the page itself.  This is needed because
clear_page_dirty() will call into page_mkclean() and would thereby violate
locking order.

[dhowells@redhat.com: Provide a page_mkclean() implementation for NOMMU]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:44 -07:00
Nick Piggin 725d704eca [PATCH] mm: VM_BUG_ON
Introduce a VM_BUG_ON, which is turned on with CONFIG_DEBUG_VM.  Use this
in the lightweight, inline refcounting functions; PageLRU and PageActive
checks in vmscan, because they're pretty well confined to vmscan.  And in
page allocate/free fastpaths which can be the hottest parts of the kernel
for kbuilds.

Unlike BUG_ON, VM_BUG_ON must not be used to execute statements with
side-effects, and should not be used outside core mm code.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:44 -07:00
James Bottomley a6ca1b99ed [PATCH] update to the kernel kmap/kunmap API
Give non-highmem architectures access to the kmap API for the purposes of
overriding (this is what the attached patch does).

The proposal is that we should now require all architectures with coherence
issues to manage data coherence via the kmap/kunmap API.  Thus driver
writers never have to write code like

    kmap(page)
    modify data in page
    flush_kernel_dcache_page(page)
    kunmap(page)

instead, kmap/kunmap will manage the coherence and driver (and filesystem)
writers don't need to worry about how to flush between kmap and kunmap.

For most architectures, the page only needs to be flushed if it was
actually written to *and* there are user mappings of it, so the best
implementation looks to be: clear the page dirty pte bit in the kernel page
tables on kmap and on kunmap, check page->mappings for user maps, and then
the dirty bit, and only flush if it both has user mappings and is dirty.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:44 -07:00
Jan Kara 3998b9301d [PATCH] jbd: fix commit of ordered data buffers
Original commit code assumes, that when a buffer on BJ_SyncData list is
locked, it is being written to disk.  But this is not true and hence it can
lead to a potential data loss on crash.  Also the code didn't count with
the fact that journal_dirty_data() can steal buffers from committing
transaction and hence could write buffers that no longer belong to the
committing transaction.  Finally it could possibly happen that we tried
writing out one buffer several times.

The patch below tries to solve these problems by a complete rewrite of the
data commit code.  We go through buffers on t_sync_datalist, lock buffers
needing write out and store them in an array.  Buffers are also immediately
refiled to BJ_Locked list or unfiled (if the write out is completed).  When
the array is full or we have to block on buffer lock, we submit all
accumulated buffers for IO.

[suitable for 2.6.18.x around the 2.6.19-rc2 timeframe]

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:44 -07:00
Jan Blunck 632bbfeee4 [PATCH] trigger a syntax error if percpu macros are incorrectly used
get_cpu_var()/per_cpu()/__get_cpu_var() arguments must be simple
identifiers.  Otherwise the arch dependent implementations might break.

This patch enforces the correct usage of the macros by producing a syntax
error if the variable is not a simple identifier.

Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:44 -07:00
Christoph Lameter 0a2966b48f [PATCH] Fix longstanding load balancing bug in the scheduler
The scheduler will stop load balancing if the most busy processor contains
processes pinned via processor affinity.

The scheduler currently only does one search for busiest cpu.  If it cannot
pull any tasks away from the busiest cpu because they were pinned then the
scheduler goes into a corner and sulks leaving the idle processors idle.

F.e.  If you have processor 0 busy running four tasks pinned via taskset,
there are none on processor 1 and one just started two processes on
processor 2 then the scheduler will not move one of the two processes away
from processor 2.

This patch fixes that issue by forcing the scheduler to come out of its
corner and retrying the load balancing by considering other processors for
load balancing.

This patch was originally developed by John Hawkes and discussed at

    http://marc.theaimsgroup.com/?l=linux-kernel&m=113901368523205&w=2.

I have removed extraneous material and gone back to equipping struct rq
with the cpu the queue is associated with since this makes the patch much
easier and it is likely that others in the future will have the same
difficulty of figuring out which processor owns which runqueue.

The overhead added through these patches is a single word on the stack if
the kernel is configured to support 32 cpus or less (32 bit).  For 32 bit
environments the maximum number of cpus that can be configued is 255 which
would result in the use of 32 bytes additional on the stack.  On IA64 up to
1k cpus can be configured which will result in the use of 128 additional
bytes on the stack.  The maximum additional cache footprint is one
cacheline.  Typically memory use will be much less than a cacheline and the
additional cpumask will be placed on the stack in a cacheline that already
contains other local variable.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: John Hawkes <hawkes@sgi.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Peter Williams <pwil3058@bigpond.net.au>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:43 -07:00
Alan Stern 7e9f4b2d3e Driver core: Don't call put methods while holding a spinlock
The klist utility routines currently call _put methods while holding a
spinlock.  This is of course illegal; a put routine could try to
unregister a device and hence need to sleep.

No problems have arisen until now because in many cases klist removals
were done synchronously, so the _put methods were never actually used.
In other cases we may simply have been lucky.

This patch (as784) reworks the klist routines so that _put methods are
called only _after_ the klist's spinlock has been released.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:40 -07:00
Alan Stern 81107bf531 Driver core: Remove unneeded routines from driver core
This patch (as783) simplifies the driver core slightly by removing four
unnecessary _get and _put methods.

It is vital that when a driver is removed from its bus's klist of
registered drivers, or when a device is removed from a driver's klist
of bound devices, that the klist updates complete synchronously.
Otherwise the kernel might try binding an unregistered driver to a
newly-registered device, or adding a device to the klist for a new
driver before it has been removed from the old driver's klist.

Since the removals must be synchronous, they don't need to update any
reference counts.  Hence the _get and _put methods can be dispensed
with.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:40 -07:00
Alan Stern f2eaae197f Driver core: Fix potential deadlock in driver core
There is a potential deadlock in the driver core.  It boils down to
the fact that bus_remove_device() calls klist_remove() instead of
klist_del(), thereby waiting until the reference count of the
klist_node in the bus's klist of devices drops to 0.  The refcount
can't reach 0 so long as a modprobe process is trying to bind a new
driver to the device being removed, by calling __driver_attach().  The
problem is that __driver_attach() tries to acquire the device's
parent's semaphore, but the caller of bus_remove_device() is quite
likely to own that semaphore already.

It isn't sufficient just to replace klist_remove() with klist_del().
Doing so runs the risk that the device would remain on the bus's klist
of devices for some time, and so could be bound to another driver even
after it was unregistered.  What's needed is a new way to distinguish
whether or not a device is registered, based on a criterion other than
whether its klist_node is linked into the bus's klist of devices.  That
way driver binding can fail when the device is unregistered, even if
it is still linked into the klist.

This patch (as782) implements the solution, by adding a new bitflag to
indiate when a struct device is registered, by testing the flag before
allowing a driver to bind a device, and by changing the definition of
the device_is_registered() inline.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:40 -07:00
Greg Kroah-Hartman 0f397f8650 PCI: enable driver multi-threaded probe
This provides a build and run-time option to turn on multhreaded probe
for all PCI drivers.  It can cause bad problems on multi-processor
machines that take a while to find their root disks, and play havoc on
machines that don't use persistant device names for block or network
devices.

But it can cause speedups on some machines, my tiny laptop's boot goes
up by 0.4 seconds, and my desktop boots up several seconds faster.

Use at your own risk!!!

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:40 -07:00
Greg Kroah-Hartman d779249ed4 Driver Core: add ability for drivers to do a threaded probe
This adds the infrastructure for drivers to do a threaded probe, and
waits at init time for all currently outstanding probes to complete.

A new kernel thread will be created when the probe() function for the
driver is called, if the multithread_probe bit is set in the driver
saying it can support this kind of operation.

I have tested this with USB and PCI, and it works, and shaves off a lot
of time in the boot process, but there are issues with finding root boot
disks, and some USB drivers assume that this can never happen, so it is
currently not enabled for any bus type.  Individual drivers can enable
this right now if they wish, and bus authors can selectivly turn it on
as well, once they determine that their subsystem will work properly
with it.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:40 -07:00
Andrew Morton f20a9ead0d sysfs: add proper sysfs_init() prototype
Don't be crufty.  Mark it __must_check too.

Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:39 -07:00
Andrew Morton f86db396ff drivers/base: check errors
Add lots of return-value checking.

<pcornelia.huck@de.ibm.com>: fix bus_rescan_devices()]
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:39 -07:00
Brian Walsh 370226449c drivers/base: Platform notify needs to occur before drivers attach to the device
The platform_notify call for Arm and PPC architectures needs to be called
before the driver attaches to the device.  The problem only presents itself
when hotplugging certain devices while the driver is already loaded.

Signed-off-by: Brian Walsh <brian@walsh.ws>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:39 -07:00
Andrew Morton 8a6914ab7c v4l-dev2: handle __must_check
We get hundreds of these:

include/media/v4l2-dev.h:348: warning: ignoring return value of 'class_device_create_file', declared with attribute warn_unused_result

Handle it, and propagate the __must_check back a level.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:39 -07:00
Andrew Morton cebc04ba9a add CONFIG_ENABLE_MUST_CHECK
Those 1500 warnings can be a bit of a pain.  Add a config option to shut them
up.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:39 -07:00
Andrew Morton 4a7fb6363f add __must_check to device management code
We're getting a lot of crashes in the sysfs/kobject/device/bus/class code and
they're very hard to diagnose.

I'm suspecting that in some cases this is because drivers aren't checking
return values and aren't handling errors correctly.  So the code blithely
blunders on and crashes later in very obscure ways.

There's just no reason to ignore errors which can and do occur.  So the patch
sprinkles __must_check all over these APIs.

Causes 1,513 new warnings.  Heh.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:39 -07:00
Yoichi Yuasa 35acfdd725 Driver core: fixed add_bind_files() definition
When CONFIG_HOTPLUG is n, add_bind_files() definition is wrong.
This patch has fixed it.

Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:39 -07:00
Dmitry Torokhov 9de72ee590 Driver core: fix comments in drivers/base/power/resume.c
Driver core: fix comments in drivers/base/power/resume.c

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:39 -07:00
Randy.Dunlap 995982ca79 sysfs_remove_bin_file: no return value, dump_stack on error
Make sysfs_remove_bin_file() void.  If it detects an error,
printk the file name and call dump_stack().

sysfs_hash_and_remove() now returns an error code indicating
its success or failure so that sysfs_remove_bin_file() can
know success/failure.

Convert the only driver that checked the return value of
sysfs_remove_bin_file().

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:39 -07:00
Randy Dunlap 10188012da kobject: must_check fixes
Check all __must_check warnings in lib/kobject.c

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:39 -07:00
Greg Kroah-Hartman 2589f1887b Driver core: add ability for devices to create and remove bin files
Makes it easier for devices to create and remove binary attribute files
so they don't have to call directly into sysfs.  This is needed to help
with the conversion from struct class_device to struct device.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:39 -07:00
Greg Kroah-Hartman c47ed219ba Class: add support for class interfaces for devices
When moving class_device usage over to device, we need to handle
class_interfaces properly with devices.  This patch adds that support.


Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:38 -07:00
Greg Kroah-Hartman c205ef4880 Driver core: create devices/virtual/ tree
This change creates a devices/virtual/CLASS_NAME tree for struct devices
that belong to a class, yet do not have a "real" struct device for a
parent.  It automatically creates the directories on the fly as needed.


Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:38 -07:00
Greg Kroah-Hartman a2de48cace Driver core: add device_rename function
The network layer needs this to convert to using struct device instead
of a struct class_device.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:38 -07:00
Greg Kroah-Hartman 2620efef70 Driver core: add ability for classes to handle devices properly
This adds two new callbacks to the class structure:
	int	(*dev_uevent)(struct device *dev, char **envp, int num_envp,
			char *buffer, int buffer_size);
	void	(*dev_release)(struct device *dev);

And one pointer:
	struct device_attribute		* dev_attrs;

which all corrispond with the same thing as the "normal" class devices
do, yet this is for when a struct device is bound to a class.

Someday soon, struct class_device will go away, and then the other
fields in this structure can be removed too.  But this is necessary in
order to get the transition to work properly.

Tested out on a network core patch that converted it to use struct
device instead of struct class_device.


Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:38 -07:00
Greg Kroah-Hartman 64bb5d2c11 Driver core: allow devices in classes to have no parent
This fixes an oops when a device is attached to a class, yet has no
"parent" device.  An example of this would be the "lo" device in the
network core.

We should create a "virtual" subdirectory under /sys/devices/ for these,
but no one seems to agree on a proper name for it yet...

Oh, and update my copyright on the driver core.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:38 -07:00
Greg Kroah-Hartman de0ff00d72 Driver core: add groups support to struct device
This is needed for the network class devices in order to be able to
convert over to use struct device.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:38 -07:00