* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
cpuset: fix regression when failed to generate sched domains
sched, signals: fix the racy usage of ->signal in account_group_xxx/run_posix_cpu_timers
sched: fix kernel warning on /proc/sched_debug access
sched: correct sched-rt-group.txt pathname in init/Kconfig
In 2007, a0acd82080 changed the default
slab allocator to SLUB, but the SLAB help text still says SLAB is the
default. This change fixes that.
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
init/Kconfig directs the user to Documentation/sched-rt-group.txt, but
the file is actually in Documentation/scheduler/sched-rt-group.txt.
This patch corrects the pathname mentioned in init/Kconfig.
Signed-off-by: Adrian Knoth <adi@drcomp.erfurt.thur.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Removed duplicated #include <linux/delay.h> in init/do_mounts_md.c.
The same compile error ("error: implicit declaration of function
'msleep'") got fixed twice:
- f8b77d3939 ("init/do_mounts_md.c:
msleep compile fix")
- 73b4a24f5f ("init/do_mounts_md.c must
#include <linux/delay.h>")
by people adding the <linux/delay.h> include in two slightly different
places. Andrew's quilt scripts happily ignore the fuzz, and will
re-apply the patch even though they had conflicts.
Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit a802dd0eb5 by moving
the call to init_workqueues() back where it belongs - after SMP has been
initialized.
It also moves stop_machine_init() - which needs workqueues - to a later
phase using a core_initcall() instead of early_initcall(). That should
satisfy all ordering requirements, and was apparently the reason why
init_workqueues() was moved to be too early.
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
stop_machine: fix error code handling on multiple cpus
stop_machine: use workqueues instead of kernel threads
workqueue: introduce create_rt_workqueue
Call init_workqueues before pre smp initcalls.
Make panic= and panic_on_oops into core_params
Make initcall_debug a core_param
core_param() for genuinely core kernel parameters
param: Fix duplicate module prefixes
module: check kernel param length at compile time, not runtime
Remove stop_machine during module load v2
module: simplify load_module.
page_cgroup_init() is called from mem_cgroup_init(). But at this
point, we cannot call alloc_bootmem().
(and this caused panic at boot.)
This patch moves page_cgroup_init() to init/main.c.
Time table is following:
==
parse_args(). # we can trust mem_cgroup_subsys.disabled bit after this.
....
cgroup_init_early() # "early" init of cgroup.
....
setup_arch() # memmap is allocated.
...
page_cgroup_init();
mem_init(); # we cannot call alloc_bootmem after this.
....
cgroup_init() # mem_cgroup is initialized.
==
Before page_cgroup_init(), mem_map must be initialized. So,
I added page_cgroup_init() to init/main.c directly.
(*) maybe this is not very clean but
- cgroup_init_early() is too early
- in cgroup_init(), we have to use vmalloc instead of alloc_bootmem().
use of vmalloc area in x86-32 is important and we should avoid very large
vmalloc() in x86-32. So, we want to use alloc_bootmem() and added page_cgroup_init()
directly to init/main.c
[akpm@linux-foundation.org: remove unneeded/bad mem_cgroup_subsys declaration]
[akpm@linux-foundation.org: fix build]
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-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>
commit 3d13731024 ("PCI: allow quirks to be
compiled out") introduced CONFIG_PCI_QUIRKS, which now shows up in each
and every .config. Fix this by making it depend on PCI.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This allows to create workqueues from within the context of
a pre smp initcall (aka early_initcall).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is the one I really wanted: now it effects module loading, it
makes sense to be able to flip it after boot.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (41 commits)
PCI: fix pci_ioremap_bar() on s390
PCI: fix AER capability check
PCI: use pci_find_ext_capability everywhere
PCI: remove #ifdef DEBUG around dev_dbg call
PCI hotplug: fix get_##name return value problem
PCI: document the pcie_aspm kernel parameter
PCI: introduce an pci_ioremap(pdev, barnr) function
powerpc/PCI: Add legacy PCI access via sysfs
PCI: Add ability to mmap legacy_io on some platforms
PCI: probing debug message uniformization
PCI: support PCIe ARI capability
PCI: centralize the capabilities code in probe.c
PCI: centralize the capabilities code in pci-sysfs.c
PCI: fix 64-vbit prefetchable memory resource BARs
PCI: replace cfg space size (256/4096) by macros.
PCI: use resource_size() everywhere.
PCI: use same arg names in PCI_VDEVICE comment
PCI hotplug: rpaphp: make debug var unique
PCI: use %pF instead of print_fn_descriptor_symbol() in quirks.c
PCI: fix hotplug get_##name return value problem
...
This patch adds the CONFIG_PCI_QUIRKS option which allows to remove all
the PCI quirks, which are not necessarily used on embedded systems when
PCI is working properly. As this is a size-reduction option, it depends
on CONFIG_EMBEDDED. It allows to save almost 12 kilobytes of kernel
code:
text data bss dec hex filename
1287806 123596 212992 1624394 18c94a vmlinux.old
1275854 123596 212992 1612442 189a9a vmlinux
-11952 0 0 -11952 -2EB0 +/-
This patch has originally been written by Zwane Mwaikambo
<zwane@arm.linux.org.uk> and is part of the Linux Tiny project.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This patch implements a new freezer subsystem in the control groups
framework. It provides a way to stop and resume execution of all tasks in
a cgroup by writing in the cgroup filesystem.
The freezer subsystem in the container filesystem defines a file named
freezer.state. Writing "FROZEN" to the state file will freeze all tasks
in the cgroup. Subsequently writing "RUNNING" will unfreeze the tasks in
the cgroup. Reading will return the current state.
* Examples of usage :
# mkdir /containers/freezer
# mount -t cgroup -ofreezer freezer /containers
# mkdir /containers/0
# echo $some_pid > /containers/0/tasks
to get status of the freezer subsystem :
# cat /containers/0/freezer.state
RUNNING
to freeze all tasks in the container :
# echo FROZEN > /containers/0/freezer.state
# cat /containers/0/freezer.state
FREEZING
# cat /containers/0/freezer.state
FROZEN
to unfreeze all tasks in the container :
# echo RUNNING > /containers/0/freezer.state
# cat /containers/0/freezer.state
RUNNING
This is the basic mechanism which should do the right thing for user space
task in a simple scenario.
It's important to note that freezing can be incomplete. In that case we
return EBUSY. This means that some tasks in the cgroup are busy doing
something that prevents us from completely freezing the cgroup at this
time. After EBUSY, the cgroup will remain partially frozen -- reflected
by freezer.state reporting "FREEZING" when read. The state will remain
"FREEZING" until one of these things happens:
1) Userspace cancels the freezing operation by writing "RUNNING" to
the freezer.state file
2) Userspace retries the freezing operation by writing "FROZEN" to
the freezer.state file (writing "FREEZING" is not legal
and returns EIO)
3) The tasks that blocked the cgroup from entering the "FROZEN"
state disappear from the cgroup's set of tasks.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: export thaw_process]
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Tested-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rewrite the vmap allocator to use rbtrees and lazy tlb flushing, and
provide a fast, scalable percpu frontend for small vmaps (requires a
slightly different API, though).
The biggest problem with vmap is actually vunmap. Presently this requires
a global kernel TLB flush, which on most architectures is a broadcast IPI
to all CPUs to flush the cache. This is all done under a global lock. As
the number of CPUs increases, so will the number of vunmaps a scaled
workload will want to perform, and so will the cost of a global TLB flush.
This gives terrible quadratic scalability characteristics.
Another problem is that the entire vmap subsystem works under a single
lock. It is a rwlock, but it is actually taken for write in all the fast
paths, and the read locking would likely never be run concurrently anyway,
so it's just pointless.
This is a rewrite of vmap subsystem to solve those problems. The existing
vmalloc API is implemented on top of the rewritten subsystem.
The TLB flushing problem is solved by using lazy TLB unmapping. vmap
addresses do not have to be flushed immediately when they are vunmapped,
because the kernel will not reuse them again (would be a use-after-free)
until they are reallocated. So the addresses aren't allocated again until
a subsequent TLB flush. A single TLB flush then can flush multiple
vunmaps from each CPU.
XEN and PAT and such do not like deferred TLB flushing because they can't
always handle multiple aliasing virtual addresses to a physical address.
They now call vm_unmap_aliases() in order to flush any deferred mappings.
That call is very expensive (well, actually not a lot more expensive than
a single vunmap under the old scheme), however it should be OK if not
called too often.
The virtual memory extent information is stored in an rbtree rather than a
linked list to improve the algorithmic scalability.
There is a per-CPU allocator for small vmaps, which amortizes or avoids
global locking.
To use the per-CPU interface, the vm_map_ram / vm_unmap_ram interfaces
must be used in place of vmap and vunmap. Vmalloc does not use these
interfaces at the moment, so it will not be quite so scalable (although it
will use lazy TLB flushing).
As a quick test of performance, I ran a test that loops in the kernel,
linearly mapping then touching then unmapping 4 pages. Different numbers
of tests were run in parallel on an 4 core, 2 socket opteron. Results are
in nanoseconds per map+touch+unmap.
threads vanilla vmap rewrite
1 14700 2900
2 33600 3000
4 49500 2800
8 70631 2900
So with a 8 cores, the rewritten version is already 25x faster.
In a slightly more realistic test (although with an older and less
scalable version of the patch), I ripped the not-very-good vunmap batching
code out of XFS, and implemented the large buffer mapping with vm_map_ram
and vm_unmap_ram... along with a couple of other tricks, I was able to
speed up a large directory workload by 20x on a 64 CPU system. I believe
vmap/vunmap is actually sped up a lot more than 20x on such a system, but
I'm running into other locks now. vmap is pretty well blown off the
profiles.
Before:
1352059 total 0.1401
798784 _write_lock 8320.6667 <- vmlist_lock
529313 default_idle 1181.5022
15242 smp_call_function 15.8771 <- vmap tlb flushing
2472 __get_vm_area_node 1.9312 <- vmap
1762 remove_vm_area 4.5885 <- vunmap
316 map_vm_area 0.2297 <- vmap
312 kfree 0.1950
300 _spin_lock 3.1250
252 sn_send_IPI_phys 0.4375 <- tlb flushing
238 vmap 0.8264 <- vmap
216 find_lock_page 0.5192
196 find_next_bit 0.3603
136 sn2_send_IPI 0.2024
130 pio_phys_write_mmr 2.0312
118 unmap_kernel_range 0.1229
After:
78406 total 0.0081
40053 default_idle 89.4040
33576 ia64_spinlock_contention 349.7500
1650 _spin_lock 17.1875
319 __reg_op 0.5538
281 _atomic_dec_and_lock 1.0977
153 mutex_unlock 1.5938
123 iget_locked 0.1671
117 xfs_dir_lookup 0.1662
117 dput 0.1406
114 xfs_iget_core 0.0268
92 xfs_da_hashname 0.1917
75 d_alloc 0.0670
68 vmap_page_range 0.0462 <- vmap
58 kmem_cache_alloc 0.0604
57 memset 0.0540
52 rb_next 0.1625
50 __copy_user 0.0208
49 bitmap_find_free_region 0.2188 <- vmap
46 ia64_sn_udelay 0.1106
45 find_inode_fast 0.1406
42 memcmp 0.2188
42 finish_task_switch 0.1094
42 __d_lookup 0.0410
40 radix_tree_lookup_slot 0.1250
37 _spin_unlock_irqrestore 0.3854
36 xfs_bmapi 0.0050
36 kmem_cache_free 0.0256
35 xfs_vn_getattr 0.0322
34 radix_tree_lookup 0.1062
33 __link_path_walk 0.0035
31 xfs_da_do_buf 0.0091
30 _xfs_buf_find 0.0204
28 find_get_page 0.0875
27 xfs_iread 0.0241
27 __strncpy_from_user 0.2812
26 _xfs_buf_initialize 0.0406
24 _xfs_buf_lookup_pages 0.0179
24 vunmap_page_range 0.0250 <- vunmap
23 find_lock_page 0.0799
22 vm_map_ram 0.0087 <- vmap
20 kfree 0.0125
19 put_page 0.0330
18 __kmalloc 0.0176
17 xfs_da_node_lookup_int 0.0086
17 _read_lock 0.0885
17 page_waitqueue 0.0664
vmap has gone from being the top 5 on the profiles and flushing the crap
out of all TLBs, to using less than 1% of kernel time.
[akpm@linux-foundation.org: cleanups, section fix]
[akpm@linux-foundation.org: fix build on alpha]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes the following compile error caused by commit
589f800bb1 ("fastboot: make the raid
autodetect code wait for all devices to init"):
CC init/do_mounts_md.o
init/do_mounts_md.c: In function 'autodetect_raid':
init/do_mounts_md.c:285: error: implicit declaration of function 'msleep'
make[2]: *** [init/do_mounts_md.o] Error 1
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patchs adds the CONFIG_AIO option which allows to remove support
for asynchronous I/O operations, that are not necessarly used by
applications, particularly on embedded devices. As this is a
size-reduction option, it depends on CONFIG_EMBEDDED. It allows to
save ~7 kilobytes of kernel code/data:
text data bss dec hex filename
1115067 119180 217088 1451335 162547 vmlinux
1108025 119048 217088 1444161 160941 vmlinux.new
-7042 -132 0 -7174 -1C06 +/-
This patch has been originally written by Matt Mackall
<mpm@selenic.com>, and is part of the Linux Tiny project.
[randy.dunlap@oracle.com: build fix]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Zach Brown <zach.brown@oracle.com>
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When unpacking the cpio into the initramfs, mtimes are not preserved by
default. This patch adds an INITRAMFS_PRESERVE_MTIME option that allows
mtimes stored in the cpio image to be used when constructing the
initramfs.
For embedded applications that run exclusively out of the initramfs, this
is invaluable:
When building embedded application initramfs images, its nice to know when
the files were actually created during the build process - that makes it
easier to see what files were modified when so we can compare the files
that are being used on the image with the files used during the build
process. This might help (for example) to determine if the target system
has all the updated files you expect to see w/o having to check MD5s etc.
In our environment, the whole system runs off the initramfs partition, and
seeing the modified times of the shared libraries (for example) helps us
find bugs that may have been introduced by the build system incorrectly
propogating outdated shared libraries into the image.
Similarly, many of the initializion/configuration files in /etc might be
dynamically built by the build system, and knowing when they were modified
helps us sanity check whether the target system has the "latest" files
etc.
Finally, we might use last modified times to determine whether a hot fix
should be applied or not to the running ramfs.
Signed-off-by: Nye Liu <nyet@nyet.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
identify_ramdisk_image() returns 0 (not -1) if a gzipped ramdisk is found:
if (buf[0] == 037 && ((buf[1] == 0213) || (buf[1] == 0236))) {
printk(KERN_NOTICE
"RAMDISK: Compressed image found at block %d\n",
start_block);
nblocks = 0;
^^^^^^^^^^^
goto done;
}
...
done:
sys_lseek(fd, start_block * BLOCK_SIZE, 0);
kfree(buf);
return nblocks;
^^^^^^^^^^^^^^
Hence correct the typo in the comment, which has existed since the
addition of compressed ramdisk support in 1.3.48.
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arjan/linux-2.6-fastboot:
raid, fastboot: hide RAID autodetect option if MD is compiled as a module
raid: make RAID autodetect default a KConfig option
warning: fix init do_mounts_md c
fastboot: make the RAID autostart code print a message just before waiting
fastboot: make the raid autodetect code wait for all devices to init
fastboot: Fix bootgraph.pl initcall name regexp
fastboot: fix issues and improve output of bootgraph.pl
Add a script to visualize the kernel boot process / time
