Commit Graph

69 Commits

Author SHA1 Message Date
Tang Chen 6056d619a8 mm: Remove unused parameter of pages_correctly_reserved()
nr_pages is not used in pages_correctly_reserved().
So remove it.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Reviewed-by: Wen Congyang <wency@cn.fujitsu.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:38 -07:00
David Rientjes 4edd7ceff0 mm, hotplug: avoid compiling memory hotremove functions when disabled
__remove_pages() is only necessary for CONFIG_MEMORY_HOTREMOVE.  PowerPC
pseries will return -EOPNOTSUPP if unsupported.

Adding an #ifdef causes several other functions it depends on to also
become unnecessary, which saves in .text when disabled (it's disabled in
most defconfigs besides powerpc, including x86).  remove_memory_block()
becomes static since it is not referenced outside of
drivers/base/memory.c.

Build tested on x86 and powerpc with CONFIG_MEMORY_HOTREMOVE both enabled
and disabled.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:37 -07:00
Yasuaki Ishimatsu 6677e3eaf4 memory-hotplug: check whether all memory blocks are offlined or not when removing memory
We remove the memory like this:

 1. lock memory hotplug
 2. offline a memory block
 3. unlock memory hotplug
 4. repeat 1-3 to offline all memory blocks
 5. lock memory hotplug
 6. remove memory(TODO)
 7. unlock memory hotplug

All memory blocks must be offlined before removing memory.  But we don't
hold the lock in the whole operation.  So we should check whether all
memory blocks are offlined before step6.  Otherwise, kernel maybe
panicked.

Offlining a memory block and removing a memory device can be two
different operations.  Users can just offline some memory blocks without
removing the memory device.  For this purpose, the kernel has held
lock_memory_hotplug() in __offline_pages().  To reuse the code for
memory hot-remove, we repeat step 1-3 to offline all the memory blocks,
repeatedly lock and unlock memory hotplug, but not hold the memory
hotplug lock in the whole operation.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Wu Jianguo <wujianguo@huawei.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-23 17:50:11 -08:00
Felipe Balbi 74fef7a8fd base: memory: fix soft/hard_offline_page permissions
those two sysfs files don't have a 'show' method,
so they shouldn't have a read permission. Thanks
to Greg Kroah-Hartman for actually looking into
the source code and figuring out we had a real bug
with these two files.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-18 11:18:13 -08:00
Lai Jiangshan 511c2aba8f mm, memory-hotplug: dynamic configure movable memory and portion memory
Add online_movable and online_kernel for logic memory hotplug.  This is
the dynamic version of "movablecore" & "kernelcore".

We have the same reason to introduce it as to introduce "movablecore" &
"kernelcore".  It has the same motive as "movablecore" & "kernelcore", but
it is dynamic/running-time:

o We can configure memory as kernelcore or movablecore after boot.

  Userspace workload is increased, we need more hugepage, we can't use
  "online_movable" to add memory and allow the system use more
  THP(transparent-huge-page), vice-verse when kernel workload is increase.

  Also help for virtualization to dynamic configure host/guest's memory,
  to save/(reduce waste) memory.

  Memory capacity on Demand

o When a new node is physically online after boot, we need to use
  "online_movable" or "online_kernel" to configure/portion it as we
  expected when we logic-online it.

  This configuration also helps for physically-memory-migrate.

o all benefit as the same as existed "movablecore" & "kernelcore".

o Preparing for movable-node, which is very important for power-saving,
  hardware partitioning and high-available-system(hardware fault
  management).

(Note, we don't introduce movable-node here.)

Action behavior:
When a memoryblock/memorysection is onlined by "online_movable", the kernel
will not have directly reference to the page of the memoryblock,
thus we can remove that memory any time when needed.

When it is online by "online_kernel", the kernel can use it.
When it is online by "online", the zone type doesn't changed.

Current constraints:
Only the memoryblock which is adjacent to the ZONE_MOVABLE
can be online from ZONE_NORMAL to ZONE_MOVABLE.

[akpm@linux-foundation.org: use min_t, cleanups]
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-11 17:22:28 -08:00
Yasuaki Ishimatsu fa7194eb99 memory hotplug: suppress "Device memoryX does not have a release() function" warning
When calling remove_memory_block(), the function shows following message
at device_release().

"Device 'memory528' does not have a release() function, it is broken and
must be fixed."

The reason is memory_block's device struct does not have a release()
function.

So the patch registers memory_block_release() to the device's release()
function for suppressing the warning message.  Additionally, the patch
moves kfree(mem) into the release function since the release function is
prepared as a means to free a memory_block struct.

Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-11 17:22:22 -08:00
Wen Congyang e90bdb7f52 memory-hotplug: update memory block's state and notify userspace
remove_memory() will be called when hot removing a memory device.  But
even if offlining memory, we cannot notice it.  So the patch updates the
memory block's state and sends notification to userspace.

Additionally, the memory device may contain more than one memory block.
If the memory block has been offlined, __offline_pages() will fail.  So we
should try to offline one memory block at a time.

Thus remove_memory() also check each memory block's state.  So there is no
need to check the memory block's state before calling remove_memory().

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09 16:23:02 +09:00
Wen Congyang a16cee10c7 memory-hotplug: preparation to notify memory block's state at memory hot remove
remove_memory() is called in two cases:
1. echo offline >/sys/devices/system/memory/memoryXX/state
2. hot remove a memory device

In the 1st case, the memory block's state is changed and the notification
that memory block's state changed is sent to userland after calling
remove_memory().  So user can notice memory block is changed.

But in the 2nd case, the memory block's state is not changed and the
notification is not also sent to userspcae even if calling
remove_memory().  So user cannot notice memory block is changed.

For adding the notification at memory hot remove, the patch just prepare
as follows:
1st case uses offline_pages() for offlining memory.
2nd case uses remove_memory() for offlining memory and changing memory block's
    state and notifing the information.

The patch does not implement notification to remove_memory().

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09 16:23:02 +09:00
Ingo Molnar cd593accdc Linux 3.3-rc7
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.18 (GNU/Linux)
 
 iQEcBAABAgAGBQJPW8yUAAoJEHm+PkMAQRiGhFIH/RGUPxGmUkJv8EP5I4HDA4dJ
 c6/PrzZCHs8rxzYzvn7ojXqZGXTOAA5ZgS9A6LkJ2sxMFvgMnkpFi6B4CwMzizS3
 vLWo/HNxbiTCNGFfQrhQB8O58uNI8wOBa87lrQfkXkDqN0cFhdjtIxeY1BD9LXIo
 qbWysGxCcZhJWHapsQ3NZaVJQnIK5vA/+mhyYP4HzbcHI3aWnbIEZ8GQKeY28Ch0
 +pct5UQBjZavV5SujaW0Xd65oIiycm8XHAQw6FxQy//DfaabauWgFteR162Q/oew
 xxUBDOHF3nO1bdteHHaYqxig0j1MbIHsqxTnE/neR8UryF04//1SFF7DYuY/1pg=
 =SV5V
 -----END PGP SIGNATURE-----

Merge tag 'v3.3-rc7' into x86/mce

Merge reason: Update from an ancient -rc1 base to an almost-final stable kernel.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-14 07:44:11 +01:00
Yinghai Lu 321bf4ed5f drivers/base/memory.c: fix memory_dev_init() long delay
One system with 2048g ram, reported soft lockup on recent kernel.

[   34.426749] cpu_dev_init done
[   61.166399] BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:1]
[   61.166733] Modules linked in:
[   61.166904] irq event stamp: 1935610
[   61.178431] hardirqs last  enabled at (1935609): [<ffffffff81ce8c05>] mutex_lock_nested+0x299/0x2b4
[   61.178923] hardirqs last disabled at (1935610): [<ffffffff81cf2bab>] apic_timer_interrupt+0x6b/0x80
[   61.198767] softirqs last  enabled at (1935476): [<ffffffff8106e59c>] __do_softirq+0x195/0x1ab
[   61.218604] softirqs last disabled at (1935471): [<ffffffff81cf359c>] call_softirq+0x1c/0x30
[   61.238408] CPU 0
[   61.238549] Modules linked in:
[   61.238744]
[   61.238825] Pid: 1, comm: swapper/0 Not tainted 3.3.0-rc1-tip-yh-02076-g962f689-dirty #171
[   61.278212] RIP: 0010:[<ffffffff810b3e3a>]  [<ffffffff810b3e3a>] lock_release+0x90/0x9c
[   61.278627] RSP: 0018:ffff883f64dbfd70  EFLAGS: 00000246
[   61.298287] RAX: ffff883f64dc0000 RBX: 0000000000000000 RCX: 000000000000008b
[   61.298690] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[   61.318383] RBP: ffff883f64dbfda0 R08: 0000000000000001 R09: 000000000000008b
[   61.338215] R10: 0000000000000000 R11: 0000000000000000 R12: ffff883f64dbfd10
[   61.338610] R13: ffff883f64dc0708 R14: ffff883f64dc0708 R15: ffffffff81095657
[   61.358299] FS:  0000000000000000(0000) GS:ffff883f7d600000(0000) knlGS:0000000000000000
[   61.378118] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[   61.378450] CR2: 0000000000000000 CR3: 00000000024af000 CR4: 00000000000007f0
[   61.398144] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   61.417918] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[   61.418260] Process swapper/0 (pid: 1, threadinfo ffff883f64dbe000, task ffff883f64dc0000)
[   61.445358] Stack:
[   61.445511]  0000000000000002 ffff897f649ba168 ffff883f64dbfe10 ffff88ff64bb57a8
[   61.458040]  0000000000000000 0000000000000000 ffff883f64dbfdc0 ffffffff81ceb1b4
[   61.458491]  000000000011608c ffff88ff64bb58a8 ffff883f64dbfdf0 ffffffff81c57638
[   61.478215] Call Trace:
[   61.478367]  [<ffffffff81ceb1b4>] _raw_spin_unlock+0x21/0x2e
[   61.497994]  [<ffffffff81c57638>] klist_next+0x9e/0xbc
[   61.498264]  [<ffffffff8148ba99>] next_device+0xe/0x1e
[   61.517867]  [<ffffffff8148c0cc>] subsys_find_device_by_id+0xb7/0xd6
[   61.518197]  [<ffffffff81498846>] find_memory_block_hinted+0x3d/0x66
[   61.537927]  [<ffffffff8149887f>] find_memory_block+0x10/0x12
[   61.538193]  [<ffffffff814988b6>] add_memory_section+0x35/0x9e
[   61.557932]  [<ffffffff827fecef>] memory_dev_init+0x68/0xda
[   61.558227]  [<ffffffff827fec01>] driver_init+0x97/0xa7
[   61.577853]  [<ffffffff827cdf3c>] kernel_init+0xf6/0x1c0
[   61.578140]  [<ffffffff81cf34a4>] kernel_thread_helper+0x4/0x10
[   61.597850]  [<ffffffff81ceb59d>] ? retint_restore_args+0xe/0xe
[   61.598144]  [<ffffffff827cde46>] ? start_kernel+0x3ab/0x3ab
[   61.617826]  [<ffffffff81cf34a0>] ? gs_change+0xb/0xb
[   61.618060] Code: 10 48 83 3b 00 eb e8 4c 89 f2 44 89 fe 4c 89 ef e8 e1 fe ff ff 65 48 8b 04 25 40 bc 00 00 c7 80 cc 06 00 00 00 00 00 00 41 54 9d <5e> 5b 41 5c 41 5d 41 5e 41 5f 5d c3 55 48 89 e5 41 57 41 89 cf
[   89.285380] memory_dev_init done

Finally it takes about 55s to create 16400 memory entries.

Root cause: for x86_64, 2048g (with 2g hole at [2g,4g), and TOP2 will be 2050g), will have 16400 memory block.

find_memory_block/subsys_find_device_by_id will be expensive with that many entries.

Actually, we don't need to find that memory block for BOOT path.

Skip that finding make it get back to normal.

[   34.466696] cpu_dev_init done
[   35.290080] memory_dev_init done

Also solved the delay with topology_init when sections_per_block is not 1.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Nathan Fontenot <nfont@austin.ibm.com>
Cc: Robin Holt <holt@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-02 15:50:05 -08:00
Ingo Molnar 4e9f44ba29 MCE recovery (data path only)
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.10 (GNU/Linux)
 
 iQIcBAABAgAGBQJPHy7VAAoJEKurIx+X31iBHcsP/1VcGuxFAL5i/zBqUqhbS7BL
 s+4or1j3NOcxIePQ9egg1L/sLzD+jmo37ObFMTzFOLwuLeodtJF6e0DXQhR7bMKz
 UqOS4WAhNxRBtZtUqIbIiMoDG4Vny1atdqxDQKzmV88ulTG2+JE5U6sGjfTdWvX7
 gZA6Vj31Dz7p6scPT2j8tnLjFV+XvVJSBp/2rgi2Nw81UzBeIRZRiWZrBMLemPCU
 T82OEffnIpSdn60sktMN/ht99yGQO31zT0c+/72Z0ysZAPlTjFbW7CZJHPZmLIVB
 tPkoTRFOf4iwjy2pZNzs9bB8ord/As3IyTxAsfYUin4N2bX27n058uTQ3CqbgEz+
 pa6C5N0ZrV9plYa9BbgCHmNIkhEONIb3WtH27uh/hZOztDA2CXzPT5mm4FOzmrJ7
 DGVBqmXth6g2jYJNT/K2QgmVMZM0CeXQnoDJP54sXzv7F4dEM5P64Lz6E1kCd5Jf
 x9O1orDnEVXssgEPVtF/eEjIQK/vF7s1BUUlMBZJwdAyTwCiD8RvueG87bApnA2z
 eO8VS62akqjpDt5sHboAGJrjcuhqnkbgtG2dn0EqONzk8DJPnhFXVLmSbvH+KuTC
 OguH2LC5N7n9Wjr5a9Duw2DdIj8njvzFrKVzo/l6r3m99u/Jby54vGk2cPLwfGvp
 /9Y+SK2Ou6LSbPiRU4dP
 =ofSb
 -----END PGP SIGNATURE-----

Merge tag 'mce-recovery-for-tip' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras into x86/mce

Implement MCE recovery for the data load error path and assorted cleanups.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-26 11:40:13 +01:00
Michael Holzheu f5138e4221 kdump: add udev events for memory online/offline
Currently no udev events for memory hotplug "online" and "offline" are
generated:

  # udevadm monitor
  # echo offline > /sys/devices/system/memory/memory4/state
  ==> No event

When kdump is loaded, kexec detects the current memory configuration and
stores it in the pre-allocated ELF core header.  Therefore, for kdump it
is necessary to reload the kdump kernel with kexec when the memory
configuration changes (e.g.  for online/offline hotplug memory).

In order to do this automatically, udev rules should be used.  This kernel
patch adds udev events for "online" and "offline".  Together with this
kernel patch, the following udev rules for online/offline have to be added
to "/etc/udev/rules.d/98-kexec.rules":

  SUBSYSTEM=="memory", ACTION=="online", PROGRAM="/etc/init.d/kdump restart"
  SUBSYSTEM=="memory", ACTION=="offline", PROGRAM="/etc/init.d/kdump restart"

[sfr@canb.auug.org.au: fixups for class to subsystem conversion]
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12 20:13:11 -08:00
Tony Luck cd42f4a3b2 HWPOISON: Clean up memory_failure() vs. __memory_failure()
There is only one caller of memory_failure(), all other users call
__memory_failure() and pass in the flags argument explicitly. The
lone user of memory_failure() will soon need to pass flags too.

Add flags argument to the callsite in mce.c. Delete the old memory_failure()
function, and then rename __memory_failure() without the leading "__".

Provide clearer message when action optional memory errors are ignored.

Acked-by: Borislav Petkov <bp@amd64.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2012-01-03 12:06:32 -08:00
Kay Sievers 10fbcf4c6c convert 'memory' sysdev_class to a regular subsystem
This moves the 'memory sysdev_class' over to a regular 'memory' subsystem
and converts the devices to regular devices. The sysdev drivers are
implemented as subsystem interfaces now.

After all sysdev classes are ported to regular driver core entities, the
sysdev implementation will be entirely removed from the kernel.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-12-21 14:48:43 -08:00
Mel Gorman 2bbcb87883 mm: memory hotplug: Check if pages are correctly reserved on a per-section basis
(Resending as I am not seeing it in -next so maybe it got lost)

mm: memory hotplug: Check if pages are correctly reserved on a per-section basis

It is expected that memory being brought online is PageReserved
similar to what happens when the page allocator is being brought up.
Memory is onlined in "memory blocks" which consist of one or more
sections. Unfortunately, the code that verifies PageReserved is
currently assuming that the memmap backing all these pages is virtually
contiguous which is only the case when CONFIG_SPARSEMEM_VMEMMAP is set.
As a result, memory hot-add is failing on those configurations with
the message;

kernel: section number XXX page number 256 not reserved, was it already online?

This patch updates the PageReserved check to lookup struct page once
per section to guarantee the correct struct page is being checked.

[Check pages within sections properly: rientjes@google.com]
[original patch by: nfont@linux.vnet.ibm.com]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-10-18 14:01:24 -07:00
Greg Kroah-Hartman de0ed36a3e Revert "memory hotplug: Correct page reservation checking"
This reverts commit 54f23eb7ba.

Turns out this patch is wrong, another correct one will follow it.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-10-18 14:00:57 -07:00
Nathan Fontenot 54f23eb7ba memory hotplug: Correct page reservation checking
The check to ensure that pages of recently added memory sections are correctly
marked as reserved before trying to online the memory is broken.  The request
to online the memory fails with the following:

kernel: section number XXX page number 256 not reserved, was it already online?

This updates the page reservation checking to check the pages of each memory
section of the memory block being onlined individually.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-09-26 16:21:14 -07:00
Anton Blanchard 61b94feafa memory hotplug: Refuse to add unaligned memory regions
The sysfs memory probe interface allows unaligned regions
to be added:

# echo 0xffffff > /sys/devices/system/memory/probe

# cat /proc/iomem
00ffffff-01fffffe : System RAM
01ffffff-02fffffe : System RAM
02ffffff-03fffffe : System RAM
03ffffff-04fffffe : System RAM
04ffffff-05fffffe : System RAM

Return -EINVAL instead of creating these bad regions.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-09-26 16:21:14 -07:00
Arun Sharma 60063497a9 atomic: use <linux/atomic.h>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26 16:49:47 -07:00
Benjamin Herrenschmidt a63fdc5156 mm: Move definition of MIN_MEMORY_BLOCK_SIZE to a header
The macro MIN_MEMORY_BLOCK_SIZE is currently defined twice in two .c
files, and I need it in a third one to fix a powerpc bug, so let's
first move it into a header

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
2011-07-12 11:08:01 +10:00
Linus Torvalds 57d19e80f4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  b43: fix comment typo reqest -> request
  Haavard Skinnemoen has left Atmel
  cris: typo in mach-fs Makefile
  Kconfig: fix copy/paste-ism for dell-wmi-aio driver
  doc: timers-howto: fix a typo ("unsgined")
  perf: Only include annotate.h once in tools/perf/util/ui/browsers/annotate.c
  md, raid5: Fix spelling error in comment ('Ofcourse' --> 'Of course').
  treewide: fix a few typos in comments
  regulator: change debug statement be consistent with the style of the rest
  Revert "arm: mach-u300/gpio: Fix mem_region resource size miscalculations"
  audit: acquire creds selectively to reduce atomic op overhead
  rtlwifi: don't touch with treewide double semicolon removal
  treewide: cleanup continuations and remove logging message whitespace
  ath9k_hw: don't touch with treewide double semicolon removal
  include/linux/leds-regulator.h: fix syntax in example code
  tty: fix typo in descripton of tty_termios_encode_baud_rate
  xtensa: remove obsolete BKL kernel option from defconfig
  m68k: fix comment typo 'occcured'
  arch:Kconfig.locks Remove unused config option.
  treewide: remove extra semicolons
  ...
2011-05-23 09:12:26 -07:00
Andrew Morton a236c71766 drivers/base/memory.c: fix warning due to "memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION"
drivers/base/memory.c: In function 'memory_block_change_state':
drivers/base/memory.c:281: warning: unused variable 'i'

less beer, more testing

Cc: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-05-12 13:27:19 -07:00
Anton Blanchard 5409d2cd84 memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION
On ppc64 the minimum memory section for hotplug is 16MB but most
recent machines have a memory block size of 256MB. This means
memory_block_change_state does 16 separate calls to
memory_section_action.

This also means we call the notifiers 16 times and the hook
in the ehea network driver is quite costly. To offline one 256MB
region takes:

# time echo offline > /sys/devices/system/memory/memory32/state
7.9s

This patch removes the loop and calls online_pages or
remove_memory once for the entire region and in doing so makes
the logic simpler since we don't have to back out if things fail
part way through.

The same test to offline one region now takes:

# time echo online > /sys/devices/system/memory/memory32/state
0.67s

Over 11 times faster.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-05-11 15:19:27 -07:00
Wanlong Gao 8572394353 drivers:base:fix the coding format of memory.c
Fix the line longer than 80 of memory_uevent function .

Signed-off-by: Wanlong Gao <wanlong.gao@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-25 15:52:40 -07:00
Nikanth Karthikesan 9f0af69b2d sysfs-memory: fix uninitialized variable warning and clean-up code.
sysfs-memory: Fix uninitialized variable warning and clean-up code.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-04-10 17:01:05 +02:00
Nathan Fontenot 6add7cd618 memory hotplug: sysfs probe routine should add all memory sections
As a follow-on to the recent patches I submitted that allowed for a sysfs
memory block to span multiple memory sections, we should also update the
probe routine to online all of the memory sections in a memory block.  Without
this patch the current code will only add a single memory section.  I think
the probe routine should add all of the memory sections in the specified memory
block so that its behavior is in line with memory hotplug actions through
the sysfs interfaces.

This patch applies on top of the previous sysfs memory updates to allow
a sysfs directory o span multiple memory sections.

https://lkml.org/lkml/2011/1/20/245

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 16:08:58 -08:00
Nathan Fontenot d33601644c memory hotplug: Update phys_index to [start|end]_section_nr
Update the 'phys_index' property of a the memory_block struct to be
called start_section_nr, and add a end_section_nr property.  The
data tracked here is the same but the updated naming is more in line
with what is stored here, namely the first and last section number
that the memory block spans.

The names presented to userspace remain the same, phys_index for
start_section_nr and end_phys_index for end_section_nr, to avoid breaking
anything in userspace.

This also updates the node sysfs code to be aware of the new capability for
a memory block to contain multiple memory sections and be aware of the memory
block structure name changes (start_section_nr).  This requires an additional
parameter to unregister_mem_sect_under_nodes so that we know which memory
section of the memory block to unregister.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Reviewed-by: Robin Holt <holt@sgi.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 16:08:57 -08:00
Nathan Fontenot 0c2c99b1b8 memory hotplug: Allow memory blocks to span multiple memory sections
Update the memory sysfs code such that each sysfs memory directory is now
considered a memory block that can span multiple memory sections per
memory block.  The default size of each memory block is SECTION_SIZE_BITS
to maintain the current behavior of having a single memory section per
memory block (i.e. one sysfs directory per memory section).

For architectures that want to have memory blocks span multiple
memory sections they need only define their own memory_block_size_bytes()
routine.

Update the memory hotplug documentation to reflect the new behaviors of
memory blocks reflected in sysfs.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Reviewed-by: Robin Holt <holt@sgi.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 16:08:57 -08:00
Nathan Fontenot 0768121597 Driver core: Add section count to memory_block struct
Add a section count property to the memory_block struct to track the number
of memory sections that have been added/removed from a memory block. This
allows us to know when the last memory section of a memory block has been
removed so we can remove the memory block.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Reviewed-by: Robin Holt <holt@sgi.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-22 10:16:44 -07:00
Nathan Fontenot 2938ffbd46 Driver core: Add mutex for adding/removing memory blocks
Add a new mutex for use in adding and removing of memory blocks.  This
is needed to avoid any race conditions in which the same memory block could
be added and removed at the same time.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Reviewed-by: Robin Holt <holt@sgi.com>
Reviewed-By: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-22 10:16:44 -07:00
Nathan Fontenot e4619c857d Driver core: Move find_memory_block routine
Move the find_memory_block() routine up to avoid needing a forward
declaration in subsequent patches.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Reviewed-by: Robin Holt <holt@sgi.com>
Reviewed-By: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-22 10:16:44 -07:00
Robin Holt 98383031ed driver core: Introduce find_memory_block_hinted which utilizes kset_find_obj_hinted.
Introduce a find_memory_block_hinted() which utilizes the
recently added kset_find_obj_hinted().

Signed-off-by: Robin Holt <holt@sgi.com>
To: Dave Hansen <haveblue@us.ibm.com>
To: Matt Tolentino <matthew.e.tolentino@intel.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-22 10:16:44 -07:00
Linus Torvalds 4dc86ae1f9 Revert "memory-hotplug: add 0x prefix to HEX block_size_bytes"
This reverts commit ba168fc37d.

It changes user-visible sysfs interfaces, and breaks some existing user
space applications which apparently rely on the fact that the output
does not contain the "0x" prefix.

Requested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-09 10:05:33 -07:00
Tejun Heo 5a0e3ad6af 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: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Heiko Carstens bc32df0089 memory hotplug: allow setting of phys_device
/sys/devices/system/memory/memoryX/phys_device is supposed to contain the
number of the physical device that the corresponding piece of memory
belongs to.

In case a physical device should be replaced or taken offline for whatever
reason it is necessary to set all corresponding memory pieces offline.
The current implementation always sets phys_device to '0' and there is no
way or hook to change that.  Seems like there was a plan to implement that
but it wasn't finished for whatever reason.

So add a weak function which architectures can override to actually set
the phys_device from within add_memory_block().

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-17 18:43:47 -07:00
Emese Revfy 9cd43611cc kobject: Constify struct kset_uevent_ops
Constify struct kset_uevent_ops.

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

 * prevents modification of data that is shared
   (referenced) by many other structure instances
   at runtime

 * detects/prevents accidental (but not intentional)
   modification attempts on archs that enforce
   read-only kernel data at runtime

 * potentially better optimized code as the compiler
   can assume that the const data cannot be changed

 * the compiler/linker move const data into .rodata
   and therefore exclude them from false sharing

Signed-off-by: Emese Revfy <re.emese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07 17:04:49 -08:00
Andi Kleen 28812fe11a driver-core: Add attribute argument to class_attribute show/store
Passing the attribute to the low level IO functions allows all kinds
of cleanups, by sharing low level IO code without requiring
an own function for every piece of data.

Also drivers can extend the attributes with own data fields
and use that in the low level function.

This makes the class attributes the same as sysdev_class attributes
and plain attributes.

This will allow further cleanups in drivers.

Full tree sweep converting all users.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07 17:04:48 -08:00
Andi Kleen 8564a6c140 sysdev: Fix type of sysdev class attribute in memory driver
This attribute is really a sysdev_class attribute, not a plain class attribute.

They are identical in layout currently, but this might not always be 
the case.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07 17:04:47 -08:00
Greg Kroah-Hartman bd796671f0 Revert "sysdev: fix prototype for memory_sysdev_class show/store functions"
This reverts commit 8ff410daa0

It should not have been sent to Linus's tree yet, as it depends
on changes that are queued up in my driver-core for the .34 kernel
merge.

Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: "Zheng, Shaohui" <shaohui.zheng@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-01-20 15:02:13 -08:00
Wu Fengguang 8ff410daa0 sysdev: fix prototype for memory_sysdev_class show/store functions
The function prototype mismatches in call stack:

                [<ffffffff81494268>] print_block_size+0x58/0x60
                [<ffffffff81487e3f>] sysdev_class_show+0x1f/0x30
                [<ffffffff811d629b>] sysfs_read_file+0xcb/0x1f0
                [<ffffffff81176328>] vfs_read+0xc8/0x180

Due to prototype mismatch, print_block_size() will sprintf() into
*attribute instead of *buf, hence user space will read the initial
zeros from *buf:
	$ hexdump /sys/devices/system/memory/block_size_bytes
	0000000 0000 0000 0000 0000
	0000008

After patch:
	cat /sys/devices/system/memory/block_size_bytes
	0x8000000

This complements commits c29af9636 and 4a0b2b4dbe.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: "Zheng, Shaohui" <shaohui.zheng@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16 12:15:39 -08:00
Wu Fengguang ba168fc37d memory-hotplug: add 0x prefix to HEX block_size_bytes
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16 12:15:39 -08:00
Robert Jennings 925cc71e51 mm: Add notifier in pageblock isolation for balloon drivers
Memory balloon drivers can allocate a large amount of memory which is not
movable but could be freed to accomodate memory hotplug remove.

Prior to calling the memory hotplug notifier chain the memory in the
pageblock is isolated.  Currently, if the migrate type is not
MIGRATE_MOVABLE the isolation will not proceed, causing the memory removal
for that page range to fail.

Rather than failing pageblock isolation if the migrateteype is not
MIGRATE_MOVABLE, this patch checks if all of the pages in the pageblock,
and not on the LRU, are owned by a registered balloon driver (or other
entity) using a notifier chain.  If all of the non-movable pages are owned
by a balloon, they can be freed later through the memory notifier chain
and the range can still be isolated in set_migratetype_isolate().

Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Brian King <brking@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Gerald Schaefer <geralds@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-12-18 14:53:36 +11:00
Andi Kleen facb6011f3 HWPOISON: Add soft page offline support
This is a simpler, gentler variant of memory_failure() for soft page
offlining controlled from user space.  It doesn't kill anything, just
tries to invalidate and if that doesn't work migrate the
page away.

This is useful for predictive failure analysis, where a page has
a high rate of corrected errors, but hasn't gone bad yet. Instead
it can be offlined early and avoided.

The offlining is controlled from sysfs, including a new generic
entry point for hard page offlining for symmetry too.

We use the page isolate facility to prevent re-allocation
race. Normally this is only used by memory hotplug. To avoid
races with memory allocation I am using lock_system_sleep().
This avoids the situation where memory hotplug is about
to isolate a page range and then hwpoison undoes that work.
This is a big hammer currently, but the simplest solution
currently.

When the page is not free or LRU we try to free pages
from slab and other caches. The slab freeing is currently
quite dumb and does not try to focus on the specific slab
cache which might own the page. This could be potentially
improved later.

Thanks to Fengguang Wu and Haicheng Li for some fixes.

[Added fix from Andrew Morton to adapt to new migrate_pages prototype]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:20:00 +01:00
Gary Hade c04fc586c1 mm: show node to memory section relationship with symlinks in sysfs
Show node to memory section relationship with symlinks in sysfs

Add /sys/devices/system/node/nodeX/memoryY symlinks for all
the memory sections located on nodeX.  For example:
/sys/devices/system/node/node1/memory135 -> ../../memory/memory135
indicates that memory section 135 resides on node1.

Also revises documentation to cover this change as well as updating
Documentation/ABI/testing/sysfs-devices-memory to include descriptions
of memory hotremove files 'phys_device', 'phys_index', and 'state'
that were previously not described there.

In addition to it always being a good policy to provide users with
the maximum possible amount of physical location information for
resources that can be hot-added and/or hot-removed, the following
are some (but likely not all) of the user benefits provided by
this change.
Immediate:
  - Provides information needed to determine the specific node
    on which a defective DIMM is located.  This will reduce system
    downtime when the node or defective DIMM is swapped out.
  - Prevents unintended onlining of a memory section that was
    previously offlined due to a defective DIMM.  This could happen
    during node hot-add when the user or node hot-add assist script
    onlines _all_ offlined sections due to user or script inability
    to identify the specific memory sections located on the hot-added
    node.  The consequences of reintroducing the defective memory
    could be ugly.
  - Provides information needed to vary the amount and distribution
    of memory on specific nodes for testing or debugging purposes.
Future:
  - Will provide information needed to identify the memory
    sections that need to be offlined prior to physical removal
    of a specific node.

Symlink creation during boot was tested on 2-node x86_64, 2-node
ppc64, and 2-node ia64 systems.  Symlink creation during physical
memory hot-add tested on a 2-node x86_64 system.

Signed-off-by: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:00 -08:00
Shaohua Li 9f1b16a51e memory_probe: fix wrong sysfs file attribute
This attribute just has a write operation.

[akpm@linux-foundation.org: use S_IWUSR as suggested by Randy]
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:52:32 -07:00
Stephen Rothwell 1f07be1c31 more sysdev API change fallout - drivers/base/memory.c
Noticed because of this warning:

  drivers/base/memory.c:279: warning: initialization from incompatible pointer type

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28 08:31:58 -07:00
Arjan van de Ven f810a5cf28 Use WARN() in drivers/base/
Use WARN() instead of a printk+WARN_ON() pair; this way the message
becomes part of the warning section for better reporting/collection.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:07 -07:00
Badari Pulavarty 5c755e9fd8 memory-hotplug: add sysfs removable attribute for hotplug memory remove
Memory may be hot-removed on a per-memory-block basis, particularly on
POWER where the SPARSEMEM section size often matches the memory-block
size.  A user-level agent must be able to identify which sections of
memory are likely to be removable before attempting the potentially
expensive operation.  This patch adds a file called "removable" to the
memory directory in sysfs to help such an agent.  In this patch, a memory
block is considered removable if;

o It contains only MOVABLE pageblocks
o It contains only pageblocks with free pages regardless of pageblock type

On the other hand, a memory block starting with a PageReserved() page will
never be considered removable.  Without this patch, the user-agent is
forced to choose a memory block to remove randomly.

Sample output of the sysfs files:

./memory/memory0/removable: 0
./memory/memory1/removable: 0
./memory/memory2/removable: 0
./memory/memory3/removable: 0
./memory/memory4/removable: 0
./memory/memory5/removable: 0
./memory/memory6/removable: 0
./memory/memory7/removable: 1
./memory/memory8/removable: 0
./memory/memory9/removable: 0
./memory/memory10/removable: 0
./memory/memory11/removable: 0
./memory/memory12/removable: 0
./memory/memory13/removable: 0
./memory/memory14/removable: 0
./memory/memory15/removable: 0
./memory/memory16/removable: 0
./memory/memory17/removable: 1
./memory/memory18/removable: 1
./memory/memory19/removable: 1
./memory/memory20/removable: 1
./memory/memory21/removable: 1
./memory/memory22/removable: 1

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:21 -07:00
Andi Kleen 4a0b2b4dbe sysdev: Pass the attribute to the low level sysdev show/store function
This allow to dynamically generate attributes and share show/store
functions between attributes. Right now most attributes are generated
by special macros and lots of duplicated code. With the attribute
passed it's instead possible to attach some data to the attribute
and then use that in shared low level functions to do different things.

I need this for the dynamically generated bank attributes in the x86
machine check code, but it'll allow some further cleanups.

I converted all users in tree to the new show/store prototype. It's a single
huge patch to avoid unbisectable sections.

Runtime tested: x86-32, x86-64
Compiled only: ia64, powerpc
Not compile tested/only grep converted: sh, arm, avr32

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-21 21:55:02 -07:00
Hannes Hering 3c82c30cd5 memory: Introduce exports for memory notifiers
This patch introduces two exports to allow modules to use memory notifiers.

Signed-off-by: Hannes Hering <hering2@de.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2008-05-13 01:31:38 -04:00