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  1. 03 Aug, 2009 11 commits
    • Tejun Heo's avatar
      x86, percpu: Collect hot percpu variables into one cacheline · bdf977b3
      Tejun Heo authored 
      On x86_64, percpu variables current_task and kernel_stack are used for
get_current() and current_thread_info() respectively and thus are
often used close to each other.  Move definition of current_task to
kernel/cpu/common.c right above kernel_stack definition and align it
to cacheline so that they always fall into the same cacheline.  Two
percpu variables defined there together - irq_stack_ptr and irq_count
- are also pretty hot and will benefit from sharing the cacheline.

For consistency, current_task definition for x86_32 is also moved to
kernel/cpu/common.c.

Putting current_task and kernel_stack into the same cacheline was
suggested by Linus Torvalds.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      bdf977b3
    • Tejun Heo's avatar
      x86, percpu: Fix DECLARE/DEFINE_PER_CPU_PAGE_ALIGNED() · 3e352aa8
      Tejun Heo authored 
      DECLARE/DEFINE_PER_CPU_PAGE_ALIGNED() put percpu variables in
.page_aligned section without adding any alignment restrictions.
Currently, this doesn't cause any problem because all users of the
macros have explicit page alignment and page-sized but it's much safer
to enforce page alignment from the macros.  After all, it's what they
claim to do.

Add __aligned(PAGE_SIZE) to DECLARE/DEFINE_PER_CPU_PAGE_ALIGNED() and
drop explicit alignment from it users.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      3e352aa8
    • Linus Torvalds's avatar
      x86, percpu: Add 'percpu_read_stable()' interface for cacheable accesses · ed8d9adf
      Linus Torvalds authored 
      This is very useful for some common things like 'get_current()' and
'get_thread_info()', which can be used multiple times in a function, and
where the result is cacheable.

tj: Added the magical undocumented "P" modifier to UP __percpu_arg()
    to force gcc to dereference the pointer value passed in via the
    "p" input constraint.  Without this, percpu_read_stable() returns
    the address of the percpu variable.  Also added comment explaining
    the difference between percpu_read() and percpu_read_stable().
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      ed8d9adf
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://neil.brown.name/md · a33a052f
      Linus Torvalds authored 
      * 'for-linus' of git://neil.brown.name/md:
  md: Use revalidate_disk to effect changes in size of device.
  md: allow raid5_quiesce to work properly when reshape is happening.
  md/raid5: set reshape_position correctly when reshape starts.
  md: Handle growth of v1.x metadata correctly.
  md: avoid array overflow with bad v1.x metadata
  md: when a level change reduces the number of devices, remove the excess.
  md: Push down data integrity code to personalities.
  md/raid6: release spare page at ->stop()
      a33a052f
    • NeilBrown's avatar
      md: Use revalidate_disk to effect changes in size of device. · 449aad3e
      NeilBrown authored 
      As revalidate_disk calls check_disk_size_change, it will cause
any capacity change of a gendisk to be propagated to the blockdev
inode.  So use that instead of mucking about with locks and
i_size_write.

Also add a call to revalidate_disk in do_md_run and a few other places
where the gendisk capacity is changed.
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      449aad3e
    • NeilBrown's avatar
      md: allow raid5_quiesce to work properly when reshape is happening. · 64bd660b
      NeilBrown authored 
      The ->quiesce method is not supposed to stop resync/recovery/reshape,
just normal IO.
But in raid5 we don't have a way to know which stripes are being
used for normal IO and which for resync etc, so we need to wait for
all stripes to be idle to be sure that all writes have completed.

However reshape keeps at least some stripe busy for an extended period
of time, so a call to raid5_quiesce can block for several seconds
needlessly.
So arrange for reshape etc to pause briefly while raid5_quiesce is
trying to quiesce the array so that the active_stripes count can
drop to zero.
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      64bd660b
    • NeilBrown's avatar
      md/raid5: set reshape_position correctly when reshape starts. · e516402c
      NeilBrown authored 
      As the internal reshape_progress counter is the main driver
for reshape, the fact that reshape_position sometimes starts with the
wrong value has minimal effect.  It is visible in sysfs and that
is all.
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      e516402c
    • NeilBrown's avatar
      md: Handle growth of v1.x metadata correctly. · 70471daf
      NeilBrown authored 
      The v1.x metadata does not have a fixed size and can grow
when devices are added.
If it grows enough to require an extra sector of storage,
we need to update the 'sb_size' to match.

Without this, md can write out an incomplete superblock with a
bad checksum, which will be rejected when trying to re-assemble
the array.

Cc: stable@kernel.org
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      70471daf
    • NeilBrown's avatar
      md: avoid array overflow with bad v1.x metadata · 3673f305
      NeilBrown authored 
      We trust the 'desc_nr' field in v1.x metadata enough to use it
as an index in an array.  This isn't really safe.
So range-check the value first.
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      3673f305
    • NeilBrown's avatar
      md: when a level change reduces the number of devices, remove the excess. · 3a981b03
      NeilBrown authored 
      When an array is changed from RAID6 to RAID5, fewer drives are
needed.  So any device that is made superfluous by the level
conversion must be marked as not-active.
For the RAID6->RAID5 conversion, this will be a drive which only
has 'Q' blocks on it.

Cc: stable@kernel.org
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      3a981b03
    • Andre Noll's avatar
      md: Push down data integrity code to personalities. · ac5e7113
      Andre Noll authored 
      This patch replaces md_integrity_check() by two new public functions:
md_integrity_register() and md_integrity_add_rdev() which are both
personality-independent.

md_integrity_register() is called from the ->run and ->hot_remove
methods of all personalities that support data integrity.  The
function iterates over the component devices of the array and
determines if all active devices are integrity capable and if their
profiles match. If this is the case, the common profile is registered
for the mddev via blk_integrity_register().

The second new function, md_integrity_add_rdev() is called from the
->hot_add_disk methods, i.e. whenever a new device is being added
to a raid array. If the new device does not support data integrity,
or has a profile different from the one already registered, data
integrity for the mddev is disabled.

For raid0 and linear, only the call to md_integrity_register() from
the ->run method is necessary.
Signed-off-by: default avatarAndre Noll <maan@systemlinux.org>
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
      ac5e7113
  3. 02 Aug, 2009 21 commits
  5. 01 Aug, 2009 3 commits
  7. 31 Jul, 2009 5 commits
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