linux-toradex.git/drivers/base/memory.c, branch v3.2.73

drivers/base/memory.c: fix show_mem_removable() to handle missing sections

2013-09-10T00:57:35+00:00

commit 21ea9f5ace3a7317cc3ba1fbc749758021a83136 upstream.

"cat /sys/devices/system/memory/memory*/removable" crashed the system.

The problem is that show_mem_removable() is passing a
bad pfn to is_mem_section_removable(), which causes

    if (!node_online(page_to_nid(page)))

to blow up.  Why is it passing in a bad pfn?

The reason is that show_mem_removable() will loop sections_per_block
times.  sections_per_block is 16, but mem->section_count is 8,
indicating holes in this memory block.  Checking that the memory section
is present before checking to see if the memory section is removable
fixes the problem.

   harp5-sys:~ # cat /sys/devices/system/memory/memory*/removable
   0
   1
   1
   1
   1
   1
   1
   1
   1
   1
   1
   1
   1
   1
   BUG: unable to handle kernel paging request at ffffea00c3200000
   IP: [] is_pageblock_removable_nolock+0x1/0x90
   PGD 83ffd4067 PUD 37bdfce067 PMD 0
   Oops: 0000 [#1] SMP
   Modules linked in: autofs4 binfmt_misc rdma_ucm rdma_cm iw_cm ib_addr ib_srp scsi_transport_srp scsi_tgt ib_ipoib ib_cm ib_uverbs ib_umad iw_cxgb3 cxgb3 mdio mlx4_en mlx4_ib ib_sa mlx4_core ib_mthca ib_mad ib_core fuse nls_iso8859_1 nls_cp437 vfat fat joydev loop hid_generic usbhid hid hwperf(O) numatools(O) dm_mod iTCO_wdt ipv6 iTCO_vendor_support igb i2c_i801 ioatdma i2c_algo_bit ehci_pci pcspkr lpc_ich i2c_core ehci_hcd ptp sg mfd_core dca rtc_cmos pps_core mperf button xhci_hcd sd_mod crc_t10dif usbcore usb_common scsi_dh_emc scsi_dh_hp_sw scsi_dh_alua scsi_dh_rdac scsi_dh gru(O) xvma(O) xfs crc32c libcrc32c thermal sata_nv processor piix mptsas mptscsih scsi_transport_sas mptbase megaraid_sas fan thermal_sys hwmon ext3 jbd ata_piix ahci libahci libata scsi_mod
   CPU: 4 PID: 5991 Comm: cat Tainted: G           O 3.11.0-rc5-rja-uv+ #10
   Hardware name: SGI UV2000/ROMLEY, BIOS SGI UV 2000/3000 series BIOS 01/15/2013
   task: ffff88081f034580 ti: ffff880820022000 task.ti: ffff880820022000
   RIP: 0010:[]  [] is_pageblock_removable_nolock+0x1/0x90
   RSP: 0018:ffff880820023df8  EFLAGS: 00010287
   RAX: 0000000000040000 RBX: ffffea00c3200000 RCX: 0000000000000004
   RDX: ffffea00c30b0000 RSI: 00000000001c0000 RDI: ffffea00c3200000
   RBP: ffff880820023e38 R08: 0000000000000000 R09: 0000000000000001
   R10: 0000000000000000 R11: 0000000000000001 R12: ffffea00c33c0000
   R13: 0000160000000000 R14: 6db6db6db6db6db7 R15: 0000000000000001
   FS:  00007ffff7fb2700(0000) GS:ffff88083fc80000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: ffffea00c3200000 CR3: 000000081b954000 CR4: 00000000000407e0
   Call Trace:
     show_mem_removable+0x41/0x70
     dev_attr_show+0x2a/0x60
     sysfs_read_file+0xf7/0x1c0
     vfs_read+0xc8/0x130
     SyS_read+0x5d/0xa0
     system_call_fastpath+0x16/0x1b

Signed-off-by: Russ Anderson 
Cc: Greg Kroah-Hartman 
Cc: "Rafael J. Wysocki" 
Cc: Yinghai Lu 
Reviewed-by: Yasuaki Ishimatsu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings

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

2011-10-18T21:01:24+00:00

(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 
Acked-by: KAMEZAWA Hiroyuki 
Tested-by: Nathan Fontenot 
Signed-off-by: Greg Kroah-Hartman

Revert "memory hotplug: Correct page reservation checking"

2011-10-18T21:00:57+00:00

This reverts commit 54f23eb7ba7619de85d8edca6e5336bc33072dbd.

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

Signed-off-by: Greg Kroah-Hartman

memory hotplug: Correct page reservation checking

2011-09-26T23:21:14+00:00

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 
Signed-off-by: Greg Kroah-Hartman

memory hotplug: Refuse to add unaligned memory regions

2011-09-26T23:21:14+00:00

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 
Signed-off-by: Greg Kroah-Hartman

atomic: use

2011-07-26T23:49:47+00:00

This allows us to move duplicated code in 
(atomic_inc_not_zero() for now) to 

Signed-off-by: Arun Sharma 
Reviewed-by: Eric Dumazet 
Cc: Ingo Molnar 
Cc: David Miller 
Cc: Eric Dumazet 
Acked-by: Mike Frysinger 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: Move definition of MIN_MEMORY_BLOCK_SIZE to a header

2011-07-12T01:08:01+00:00

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 
Acked-by: Ingo Molnar

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial

2011-05-23T16:12:26+00:00

* '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
  ...

drivers/base/memory.c: fix warning due to "memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION"

2011-05-12T20:27:19+00:00

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 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION

2011-05-11T22:19:27+00:00

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 
Signed-off-by: Greg Kroah-Hartman