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
* 'proc' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc:
proc: remove kernel.maps_protect
proc: remove now unneeded ADDBUF macro
[PATCH] proc: show personality via /proc/pid/personality
[PATCH] signal, procfs: some lock_task_sighand() users do not need rcu_read_lock()
proc: move PROC_PAGE_MONITOR to fs/proc/Kconfig
proc: make grab_header() static
proc: remove unused get_dma_list()
proc: remove dummy vmcore_open()
proc: proc_sys_root tweak
proc: fix return value of proc_reg_open() in "too late" case
Fixed up trivial conflict in removed file arch/sparc/include/asm/dma_32.h
RAID autodetect has the side effect of requiring synchronisation
of all device drivers, which can make the boot several seconds longer
(I've measured 7 on one of my laptops).... even for systems that don't
have RAID setup for the root filesystem (the only FS where this matters).
This patch makes the default for autodetect a config option; either way
the user can always override via the kernel command line.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: NeilBrown <neilb@suse.de>
fix warning:
init/do_mounts_md.c: In function ‘md_run_setup’:
init/do_mounts_md.c:282: warning: ISO C90 forbids mixed declarations and code
also, use the opportunity to put the RAID autodetection code
into a separate function - this also solves a checkpatch style warning.
No code changed:
md5:
aa36a35faef371b05f1974ad583bdbbd do_mounts_md.o.before.asm
aa36a35faef371b05f1974ad583bdbbd do_mounts_md.o.after.asm
Signed-off-by: Ingo Molnar <mingo@elte.hu>
As requested/suggested by Neil Brown: make the raid code print that it's
about to wait for probing to be done as well as give a suggestion on how
to disable the probing if the user doesn't use raid.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com
The raid autodetect code really needs to have all devices probed before
it can detect raid arrays; not doing so would give rather messy situations
where arrays would get detected as degraded while they shouldn't be etc.
This is in preparation of removing the "wait for everything to init"
code that makes everyone pay, not just raid users.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
When optimizing the kernel boot time, it's very valuable to visualize
what is going on at which time. In addition, with some of the initializing
going asynchronous soon, it's valuable to track/print which worker thread
is executing the initialization.
This patch adds a script to turn a dmesg into a SVG graph (that can be
shown with tools such as InkScape, Gimp or Firefox) and a small change
to the initcall code to print the PID of the thread calling the initcall
(so that the script can work out the parallelism).
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
DEBUG_BLOCK_EXT_DEVT shuffles SCSI and IDE device numbers and root
device number set using rdev become meaningless. Root devices should
be explicitly specified using textual names. Warn about it if root
can't be found and DEBUG_BLOCK_EXT_DEVT is enabled. Also, add warning
to the help text.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
.. small detail, but the silly e1000e initcall warning debugging caused
me to look at this code. Rather than gouge my eyes out with a spoon, I
just fixed it.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I noticed that sysctl_check.o was the largest object file in
a allnoconfig build in kernel/*.
36243 0 0 36243 8d93 kernel/sysctl_check.o
This is because it was default y and && EMBEDDED. But I don't
really see a need for a non kernel developer to have their
sysctls checked all the time.
So move the Kconfig into the kernel debugging section and
also drop the default y and the EMBEDDED check.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel has this really nice facility where if you put "initcall_debug"
on the kernel commandline, it'll print which function it's going to
execute just before calling an initcall, and then after the call completes
it will
1) print if it had an error code
2) checks for a few simple bugs (like leaving irqs off)
and
3) print how long the init call took in milliseconds.
While trying to optimize the boot speed of my laptop, I have been loving
number 3 to figure out what to optimize... ... and then I wished that
the same thing was done for module loading.
This patch makes the module loader use this exact same functionality; it's
a logical extension in my view (since modules are just sort of late
binding initcalls anyway) and so far I've found it quite useful in finding
where things are too slow in my boot.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Given that the init/Kconfig file uses a "menuconfig" directive for
modules already, might as well wrap all the submenu entries in an "if"
to toss all those dependencies.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes:
kbuild: scripts/ver_linux: don't set PATH
Kconfig/init: change help text to match default value
kbuild: genksyms: Include extern information in dumps
kbuild: genksyms parser: fix the __attribute__ rule
kbuild: scripts/genksyms/lex.l: add %option noinput
kconfig: scripts/kconfig/zconf.l: add %option noinput
kbuild: fix O=... build of um
Change the "If unsure" message to match the default value.
Signed-off-by: John Kacur <jkacur at gmail dot com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
commit fb6624ebd9 (initrd: Fix virtual/physical
mix-up in overwrite test) introduced the compiler warning below on mips,
as its virt_to_page() doesn't cast the passed address to unsigned long
internally, unlike on most other architectures:
init/main.c: In function `start_kernel':
init/main.c:633: warning: passing argument 1 of `virt_to_phys' makes pointer from integer without a cast
init/main.c:636: warning: passing argument 1 of `virt_to_phys' makes pointer from integer without a cast
For now, kill the warning by explicitly casting initrd_start to `void *', as
that's the type it should really be.
Reported-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rabin Vincent noticed that there's a stray <6> in BogoMIPS printk:
> Remove the extra KERN_INFO which causes this:
> Calibrating delay loop... <6>179.40 BogoMIPS (lpj=897024)
> - printk(KERN_INFO "%lu.%02lu BogoMIPS (lpj=%lu)\n",
> - loops_per_jiffy/(500000/HZ),
> - (loops_per_jiffy/(5000/HZ)) % 100, loops_per_jiffy);
> + printk("%lu.%02lu BogoMIPS (lpj=%lu)\n",
> + loops_per_jiffy/(500000/HZ),
> + (loops_per_jiffy/(5000/HZ)) % 100, loops_per_jiffy);
> }
How about just using KERN_CONT and leaving the whitespace
for a patch that does the entire file?
Reported-by: Rabin Vincent <rabin@rab.in>
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-next: (25 commits)
setlocalversion: do not describe if there is nothing to describe
kconfig: fix typos: "Suport" -> "Support"
kconfig: make defconfig is no longer chatty
kconfig: make oldconfig is now less chatty
kconfig: speed up all*config + randconfig
kconfig: set all new symbols automatically
kconfig: add diffconfig utility
kbuild: remove Module.markers during mrproper
kbuild: sparse needs CF not CHECKFLAGS
kernel-doc: handle/strip __init
vmlinux.lds: move __attribute__((__cold__)) functions back into final .text section
init: fix URL of "The GNU Accounting Utilities"
kbuild: add arch/$ARCH/include to search path
kbuild: asm symlink support for arch/$ARCH/include
kbuild: support arch/$ARCH/include for tags, cscope
kbuild: prepare headers_* for arch/$ARCH/include
kbuild: install all headers when arch is changed
kbuild: make clean removes *.o.* as well
kbuild: optimize headers_* targets
kbuild: only one call for include/ in make headers_*
...
This patch makes the needlessly global root_device_name static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A previous patch added the early_initcall(), to allow a cleaner hooking of
pre-SMP initcalls. Now we remove the older interface, converting all
existing users to the new one.
[akpm@linux-foundation.org: cleanups]
[akpm@linux-foundation.org: build fix]
[kosaki.motohiro@jp.fujitsu.com: warning fix]
[kosaki.motohiro@jp.fujitsu.com: warning fix]
Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: 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>
Added early initcall (pre-SMP) support, using an identical interface to
that of regular initcalls. Functions called from do_pre_smp_initcalls()
could be converted to use this cleaner interface.
This is required by CPU hotplug, because early users have to register
notifiers before going SMP. One such CPU hotplug user is the relay
interface with buffer-only channels, which needs to register such a
notifier, to be usable in early code. This in turn is used by kmemtrace.
Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Following patch corrects URL of "The GNU Accounting Utilities" in init/Kconfig.
Noticed by: Bart Van Assche" <bart.vanassche@gmail.com>
Signed-off-by: S.Çağlar Onur <caglar@pardus.org.tr>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
This patch adds proper prototypes for pid{hash,map}_init() in
include/linux/pid_namespace.h
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
int Version_* is only used with ksymoops, which is only needed (according
to README and Documentation/Changes) if CONFIG_KALLSYMS is NOT defined.
Therefore this patch defines version_string only if CONFIG_KALLSYMS is not
defined.
Signed-off-by: Daniel Guilak <daniel@danielguilak.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>
Inflate requires some dynamic memory allocation very early in the boot
process and this is provided with a set of four functions:
malloc/free/gzip_mark/gzip_release.
The old inflate code used a mark/release strategy rather than implement
free. This new version instead keeps a count on the number of outstanding
allocations and when it hits zero, it resets the malloc arena.
This allows removing all the mark and release implementations and unifying
all the malloc/free implementations.
The architecture-dependent code must define two addresses:
- free_mem_ptr, the address of the beginning of the area in which
allocations should be made
- free_mem_end_ptr, the address of the end of the area in which
allocations should be made. If set to 0, then no check is made on
the number of allocations, it just grows as much as needed
The architecture-dependent code can also provide an arch_decomp_wdog()
function call. This function will be called several times during the
decompression process, and allow to notify the watchdog that the system is
still running. If an architecture provides such a call, then it must
define ARCH_HAS_DECOMP_WDOG so that the generic inflate code calls
arch_decomp_wdog().
Work initially done by Matt Mackall, updated to a recent version of the
kernel and improved by me.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Mikael Starvik <mikael.starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There seems to be little point in explicitly setting, then testing the macro
BUILD_CRAMDISK within the context of a single source file.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Every file should include the headers containing the externs for its
global code (in this case for rd_doload).
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'sched/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: hrtick_enabled() should use cpu_active()
sched, x86: clean up hrtick implementation
sched: fix build error, provide partition_sched_domains() unconditionally
sched: fix warning in inc_rt_tasks() to not declare variable 'rq' if it's not needed
cpu hotplug: Make cpu_active_map synchronization dependency clear
cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2)
sched: rework of "prioritize non-migratable tasks over migratable ones"
sched: reduce stack size in isolated_cpu_setup()
Revert parts of "ftrace: do not trace scheduler functions"
Fixed up conflicts in include/asm-x86/thread_info.h (due to the
TIF_SINGLESTEP unification vs TIF_HRTICK_RESCHED removal) and
kernel/sched_fair.c (due to cpu_active_map vs for_each_cpu_mask_nr()
introduction).
... as preparation for removing it completely, make it an
invisible bool defaulting to yes.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
module.c and module.h conatains code for finding
exported symbols which are declared with EXPORT_UNUSED_SYMBOL,
and this code is compiled in even if CONFIG_UNUSED_SYMBOLS is not set
and thus there can be no EXPORT_UNUSED_SYMBOLs in modules anyway
(because EXPORT_UNUSED_SYMBOL(x) are compiled out to nothing then).
This patch adds required #ifdefs.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
On recent kernels, I get the following error when using an initrd:
| initrd overwritten (0x00b78000 < 0x07668000) - disabling it.
My Amiga 4000 has 12 MiB of RAM at physical address 0x07400000 (virtual
0x00000000).
The initrd is located at the end of RAM: 0x00b78000 - 0x00c00000 (virtual).
The overwrite test compares the (virtual) initrd location to the (physical)
first available memory location, which fails.
This patch converts initrd_start to a page frame number, so it can safely be
compared with min_low_pfn.
Before the introduction of discontiguous memory support on m68k
(12d810c1b8), min_low_pfn was just left
untouched by the m68k-specific code (zero, I guess), and everything worked
fine.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is based on Linus' idea of creating cpu_active_map that prevents
scheduler load balancer from migrating tasks to the cpu that is going
down.
It allows us to simplify domain management code and avoid unecessary
domain rebuilds during cpu hotplug event handling.
Please ignore the cpusets part for now. It needs some more work in order
to avoid crazy lock nesting. Although I did simplfy and unify domain
reinitialization logic. We now simply call partition_sched_domains() in
all the cases. This means that we're using exact same code paths as in
cpusets case and hence the test below cover cpusets too.
Cpuset changes to make rebuild_sched_domains() callable from various
contexts are in the separate patch (right next after this one).
This not only boots but also easily handles
while true; do make clean; make -j 8; done
and
while true; do on-off-cpu 1; done
at the same time.
(on-off-cpu 1 simple does echo 0/1 > /sys/.../cpu1/online thing).
Suprisingly the box (dual-core Core2) is quite usable. In fact I'm typing
this on right now in gnome-terminal and things are moving just fine.
Also this is running with most of the debug features enabled (lockdep,
mutex, etc) no BUG_ONs or lockdep complaints so far.
I believe I addressed all of the Dmitry's comments for original Linus'
version. I changed both fair and rt balancer to mask out non-active cpus.
And replaced cpu_is_offline() with !cpu_active() in the main scheduler
code where it made sense (to me).
Signed-off-by: Max Krasnyanskiy <maxk@qualcomm.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Gregory Haskins <ghaskins@novell.com>
Cc: dmitry.adamushko@gmail.com
Cc: pj@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for_linus' of git://git.infradead.org/~dedekind/ubifs-2.6:
UBIFS: include to compilation
UBIFS: add new flash file system
UBIFS: add brief documentation
MAINTAINERS: add UBIFS section
do_mounts: allow UBI root device name
VFS: export sync_sb_inodes
VFS: move inode_lock into sync_sb_inodes
* 'generic-ipi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (22 commits)
generic-ipi: more merge fallout
generic-ipi: merge fix
x86, visws: use mach-default/entry_arch.h
x86, visws: fix generic-ipi build
generic-ipi: fixlet
generic-ipi: fix s390 build bug
generic-ipi: fix linux-next tree build failure
fix: "smp_call_function: get rid of the unused nonatomic/retry argument"
fix: "smp_call_function: get rid of the unused nonatomic/retry argument"
fix "smp_call_function: get rid of the unused nonatomic/retry argument"
on_each_cpu(): kill unused 'retry' parameter
smp_call_function: get rid of the unused nonatomic/retry argument
sh: convert to generic helpers for IPI function calls
parisc: convert to generic helpers for IPI function calls
mips: convert to generic helpers for IPI function calls
m32r: convert to generic helpers for IPI function calls
arm: convert to generic helpers for IPI function calls
alpha: convert to generic helpers for IPI function calls
ia64: convert to generic helpers for IPI function calls
powerpc: convert to generic helpers for IPI function calls
...
Fix trivial conflicts due to rcu updates in kernel/rcupdate.c manually
Currently x86_32, sh and cris-v32 provide per-device coherent dma
memory allocator.
However their implementation is nearly identical. Refactor out
common code to be reused by them.
Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
