Skip to content

K
kernel_linux

OpenHarmony / kernel_linux
上一次同步 大约 4 年

通知 14
Star 8
Fork 2
K
kernel_linux
切换分支/标签
  1. 22 11月, 2006 2 次提交
    • D
      WorkStruct: Pass the work_struct pointer instead of context data · 65f27f38
      由 David Howells 提交于 
      Pass the work_struct pointer to the work function rather than context data.
The work function can use container_of() to work out the data.

For the cases where the container of the work_struct may go away the moment the
pending bit is cleared, it is made possible to defer the release of the
structure by deferring the clearing of the pending bit.

To make this work, an extra flag is introduced into the management side of the
work_struct.  This governs auto-release of the structure upon execution.

Ordinarily, the work queue executor would release the work_struct for further
scheduling or deallocation by clearing the pending bit prior to jumping to the
work function.  This means that, unless the driver makes some guarantee itself
that the work_struct won't go away, the work function may not access anything
else in the work_struct or its container lest they be deallocated..  This is a
problem if the auxiliary data is taken away (as done by the last patch).

However, if the pending bit is *not* cleared before jumping to the work
function, then the work function *may* access the work_struct and its container
with no problems.  But then the work function must itself release the
work_struct by calling work_release().

In most cases, automatic release is fine, so this is the default.  Special
initiators exist for the non-auto-release case (ending in _NAR).
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
      65f27f38
    • D
      WorkStruct: Separate delayable and non-delayable events. · 52bad64d
      由 David Howells 提交于 
      Separate delayable work items from non-delayable work items be splitting them
into a separate structure (delayed_work), which incorporates a work_struct and
the timer_list removed from work_struct.

The work_struct struct is huge, and this limits it's usefulness.  On a 64-bit
architecture it's nearly 100 bytes in size.  This reduces that by half for the
non-delayable type of event.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
      52bad64d
  3. 04 11月, 2006 1 次提交
  5. 22 10月, 2006 1 次提交
  7. 08 10月, 2006 1 次提交
  9. 06 10月, 2006 1 次提交
  11. 04 10月, 2006 2 次提交
  13. 30 9月, 2006 1 次提交
    • D
      [PATCH] single bit flip detector · aa83aa40
      由 Dave Jones 提交于 
      In cases where we detect a single bit has been flipped, we spew the usual
slab corruption message, which users instantly think is a kernel bug.  In a
lot of cases, single bit errors are down to bad memory, or other hardware
failure.

This patch adds an extra line to the slab debug messages in those cases, in
the hope that users will try memtest before they report a bug.

000: 6b 6b 6b 6b 6a 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
Single bit error detected. Possibly bad RAM. Run memtest86.

[akpm@osdl.org: cleanups]
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      aa83aa40
  15. 27 9月, 2006 3 次提交
    • C
      [PATCH] GFP_THISNODE for the slab allocator · 765c4507
      由 Christoph Lameter 提交于 
      This patch insures that the slab node lists in the NUMA case only contain
slabs that belong to that specific node.  All slab allocations use
GFP_THISNODE when calling into the page allocator.  If an allocation fails
then we fall back in the slab allocator according to the zonelists appropriate
for a certain context.

This allows a replication of the behavior of alloc_pages and alloc_pages node
in the slab layer.

Currently allocations requested from the page allocator may be redirected via
cpusets to other nodes.  This results in remote pages on nodelists and that in
turn results in interrupt latency issues during cache draining.  Plus the slab
is handing out memory as local when it is really remote.

Fallback for slab memory allocations will occur within the slab allocator and
not in the page allocator.  This is necessary in order to be able to use the
existing pools of objects on the nodes that we fall back to before adding more
pages to a slab.

The fallback function insures that the nodes we fall back to obey cpuset
restrictions of the current context.  We do not allocate objects from outside
of the current cpuset context like before.

Note that the implementation of locality constraints within the slab allocator
requires importing logic from the page allocator.  This is a mischmash that is
not that great.  Other allocators (uncached allocator, vmalloc, huge pages)
face similar problems and have similar minimal reimplementations of the basic
fallback logic of the page allocator.  There is another way of implementing a
slab by avoiding per node lists (see modular slab) but this wont work within
the existing slab.

V1->V2:
- Use NUMA_BUILD to avoid #ifdef CONFIG_NUMA
- Exploit GFP_THISNODE being 0 in the NON_NUMA case to avoid another
  #ifdef

[akpm@osdl.org: build fix]
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      765c4507
    • C
      [PATCH] slab: fix kmalloc_node applying memory policies if nodeid == numa_node_id() · de3083ec
      由 Christoph Lameter 提交于 
      kmalloc_node() falls back to ___cache_alloc() under certain conditions and
at that point memory policies may be applied redirecting the allocation
away from the current node.  Therefore kmalloc_node(...,numa_node_id()) or
kmalloc_node(...,-1) may not return memory from the local node.

Fix this by doing the policy check in __cache_alloc() instead of
____cache_alloc().

This version here is a cleanup of Kiran's patch.

- Tested on ia64.
- Extra material removed.
- Consolidate the exit path if alternate_node_alloc() returned an object.

[akpm@osdl.org: warning fix]
Signed-off-by: NAlok N Kataria <alok.kataria@calsoftinc.com>
Signed-off-by: NRavikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: NShai Fultheim <shai@scalex86.org>
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      de3083ec
    • A
      [PATCH] Make kmem_cache_destroy() return void · 133d205a
      由 Alexey Dobriyan 提交于 
      un-, de-, -free, -destroy, -exit, etc functions should in general return
void.  Also,

There is very little, say, filesystem driver code can do upon failed
kmem_cache_destroy().  If it will be decided to BUG in this case, BUG
should be put in generic code, instead.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      133d205a
  17. 26 9月, 2006 11 次提交
  19. 01 8月, 2006 2 次提交
  21. 14 7月, 2006 3 次提交
  23. 04 7月, 2006 1 次提交
  25. 01 7月, 2006 3 次提交
    • C
      [PATCH] slab: consolidate code to free slabs from freelist · ed11d9eb
      由 Christoph Lameter 提交于 
      Post and discussion:
http://marc.theaimsgroup.com/?t=115074342800003&r=1&w=2

Code in __shrink_node() duplicates code in cache_reap()

Add a new function drain_freelist that removes slabs with objects that are
already free and use that in various places.

This eliminates the __node_shrink() function and provides the interrupt
holdoff reduction from slab_free to code that used to call __node_shrink.

[akpm@osdl.org: build fixes]
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      ed11d9eb
    • C
      [PATCH] zoned vm counters: conversion of nr_slab to per zone counter · 9a865ffa
      由 Christoph Lameter 提交于 
      - Allows reclaim to access counter without looping over processor counts.

- Allows accurate statistics on how many pages are used in a zone by
  the slab. This may become useful to balance slab allocations over
  various zones.

[akpm@osdl.org: bugfix]
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      9a865ffa
    • C
      [PATCH] zoned vm counters: basic ZVC (zoned vm counter) implementation · 2244b95a
      由 Christoph Lameter 提交于 
      Per zone counter infrastructure

The counters that we currently have for the VM are split per processor.  The
processor however has not much to do with the zone these pages belong to.  We
cannot tell f.e.  how many ZONE_DMA pages are dirty.

So we are blind to potentially inbalances in the usage of memory in various
zones.  F.e.  in a NUMA system we cannot tell how many pages are dirty on a
particular node.  If we knew then we could put measures into the VM to balance
the use of memory between different zones and different nodes in a NUMA
system.  For example it would be possible to limit the dirty pages per node so
that fast local memory is kept available even if a process is dirtying huge
amounts of pages.

Another example is zone reclaim.  We do not know how many unmapped pages exist
per zone.  So we just have to try to reclaim.  If it is not working then we
pause and try again later.  It would be better if we knew when it makes sense
to reclaim unmapped pages from a zone.  This patchset allows the determination
of the number of unmapped pages per zone.  We can remove the zone reclaim
interval with the counters introduced here.

Futhermore the ability to have various usage statistics available will allow
the development of new NUMA balancing algorithms that may be able to improve
the decision making in the scheduler of when to move a process to another node
and hopefully will also enable automatic page migration through a user space
program that can analyse the memory load distribution and then rebalance
memory use in order to increase performance.

The counter framework here implements differential counters for each processor
in struct zone.  The differential counters are consolidated when a threshold
is exceeded (like done in the current implementation for nr_pageache), when
slab reaping occurs or when a consolidation function is called.

Consolidation uses atomic operations and accumulates counters per zone in the
zone structure and also globally in the vm_stat array.  VM functions can
access the counts by simply indexing a global or zone specific array.

The arrangement of counters in an array also simplifies processing when output
has to be generated for /proc/*.

Counters can be updated by calling inc/dec_zone_page_state or
_inc/dec_zone_page_state analogous to *_page_state.  The second group of
functions can be called if it is known that interrupts are disabled.

Special optimized increment and decrement functions are provided.  These can
avoid certain checks and use increment or decrement instructions that an
architecture may provide.

We also add a new CONFIG_DMA_IS_NORMAL that signifies that an architecture can
do DMA to all memory and therefore ZONE_NORMAL will not be populated.  This is
only currently set for IA64 SGI SN2 and currently only affects
node_page_state().  In the best case node_page_state can be reduced to
retrieving a single counter for the one zone on the node.

[akpm@osdl.org: cleanups]
[akpm@osdl.org: export vm_stat[] for filesystems]
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      2244b95a
  27. 28 6月, 2006 5 次提交
  29. 23 6月, 2006 3 次提交
    • P
      [PATCH] slab: kmalloc, kzalloc comments cleanup and fix · 800590f5
      由 Paul Drynoff 提交于 
      - Move comments for kmalloc to right place, currently it near __do_kmalloc

- Comments for kzalloc

- More detailed comments for kmalloc

- Appearance of "kmalloc" and "kzalloc" man pages after "make mandocs"

[rdunlap@xenotime.net: simplification]
Signed-off-by: NPaul Drynoff <pauldrynoff@gmail.com>
Acked-by: NRandy Dunlap <rdunlap@xenotime.net>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      800590f5
    • I
      [PATCH] mm/slab.c: fix early init assumption · e0a42726
      由 Ingo Molnar 提交于 
      The SLAB bootstrap code assumes that the first two kmalloc caches created
(the INDEX_AC and INDEX_L3 kmalloc caches) wont be off-slab.  But due to AC
and L3 structure size increase in lockdep, one of them ended up being
off-slab, and subsequently crashing with:

Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP:
 [<ffffffff80267478>] kmem_cache_alloc+0x26/0x7d

The fix is to introduce a bootstrap flag and to use it to prevent off-slab
caches being created so early during bootup.

(The calculation for off-slab caches is quite complex so i didnt want to
complicate things with introducing yet another INDEX_ calculation, the flag
approach is simpler and smaller.)
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      e0a42726
    • P
      [PATCH] slab: verify pointers before free · ddc2e812
      由 Pekka Enberg 提交于 
      Passing an invalid pointer to kfree() and kmem_cache_free() is likely to
cause bad memory corruption or even take down the whole system because the
bad pointer is likely reused immediately due to the per-CPU caches.  Until
now, we don't do any verification for this if CONFIG_DEBUG_SLAB is
disabled.

As suggested by Linus, add PageSlab check to page_to_cache() and
page_to_slab() to verify pointers passed to kfree().  Also, move the
stronger check from cache_free_debugcheck() to kmem_cache_free() to ensure
the passed pointer actually belongs to the cache we're about to free the
object.

For page_to_cache() and page_to_slab(), the assertions should have
virtually no extra cost (two instructions, no data cache pressure) and for
kmem_cache_free() the overhead should be minimal.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Cc: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      ddc2e812