Let's put my money where my mouth is. Smaller code is almost always
faster, if only because a single I$ miss ends up leaving a lot of cycles
to make up for. And system software - kernels in particular - are known
for taking more cache misses than most other kinds.
On my random config, this made the kernel about 10% smaller, and lmbench
seems to say that it's pretty uniformly faster too. Your milage may vary.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
KOBJECT_UEVENT=n seems to be a common pitfall for udev users in 2.6.14 .
-mm already contains a bigger patch removing this option that is IMHO
too big for being applied now to 2.6.15-rc.
This patch simply allows KOBJECT_UEVENT=n only if EMBEDDED.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Run idle threads with preempt disabled.
Also corrected a bugs in arm26's cpu_idle (make it actually call schedule()).
How did it ever work before?
Might fix the CPU hotplugging hang which Nigel Cunningham noted.
We think the bug hits if the idle thread is preempted after checking
need_resched() and before going to sleep, then the CPU offlined.
After calling stop_machine_run, the CPU eventually returns from preemption and
into the idle thread and goes to sleep. The CPU will continue executing
previous idle and have no chance to call play_dead.
By disabling preemption until we are ready to explicitly schedule, this bug is
fixed and the idle threads generally become more robust.
From: alexs <ashepard@u.washington.edu>
PPC build fix
From: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
MIPS build fix
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
drivers/block/ is right now a mix of core and driver parts. Lets move
the core parts to a new top level directory. Al will move the fs/
related block parts to block/ next.
Signed-off-by: Jens Axboe <axboe@suse.de>
Commit f2b36db692 causes a bootup hang on
at least one machine. Revert for now until we understand why. The old
code may be ugly, but it works.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Try to make the INIT_ENV_ARG_LIMIT help text more readable and
understandable.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
All kinds of ugliness exists because we don't initialize
the apics during init_IRQs.
- We calibrate jiffies in non apic mode even when we are using apics.
- We have to have special code to initialize the apics when non-smp.
- The legacy i8259 must exist and be setup correctly, even
when we won't use it past initialization.
- The kexec on panic code must restore the state of the io_apics.
- init/main.c needs a special case for !smp smp_init on x86
In addition to pure code movement I needed a couple
of non-obvious changes:
- Move setup_boot_APIC_clock into APIC_late_time_init for
simplicity.
- Use cpu_khz to generate a better approximation of loops_per_jiffies
so I can verify the timer interrupt is working.
- Call setup_apic_nmi_watchdog again after cpu_khz is initialized on
the boot cpu.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Besides freeing initrd memory, also clear out the now dangling pointers to
it, to make sure accidental late use attempts can be detected.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Since early userspace was added, there's no way to override which init to
run from it. Some people tack on an extra cpio archive with a link from
/init depending on what they want to run, but that's sometimes impractical.
Changing the "init=" to also override the early userspace isn't feasible,
since it is still used to indicate what init to run from disk when early
userspace has completed doing whatever it's doing (i.e. load filesystem
modules and drivers).
Instead, introduce "rdinit=" and make it override the default "/init" if
specified.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I passed init=/mylinuxrc to the kernel on the command line. The kernel
silently dropped down to exec /sbin/init. It turned out that /mylinuxrc
had improper permissions. Without any warning message from the kernel that
something was wrong it took awhile to find the issue. The patch below adds
a warning.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds a new kernel debug feature: CONFIG_DETECT_SOFTLOCKUP.
When enabled then per-CPU watchdog threads are started, which try to run
once per second. If they get delayed for more than 10 seconds then a
callback from the timer interrupt detects this condition and prints out a
warning message and a stack dump (once per lockup incident). The feature
is otherwise non-intrusive, it doesnt try to unlock the box in any way, it
only gets the debug info out, automatically, and on all CPUs affected by
the lockup.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-Off-By: Matthias Urlichs <smurf@smurf.noris.de>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch is against 2.6.10, but still applies cleanly. It's just
s/driverfs/sysfs/ in this file.
Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Of this type, mostly:
CHECK net/ipv6/netfilter.c
net/ipv6/netfilter.c:96:12: warning: symbol 'ipv6_netfilter_init' was not declared. Should it be static?
net/ipv6/netfilter.c:101:6: warning: symbol 'ipv6_netfilter_fini' was not declared. Should it be static?
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If CONFIG_AUTO_LOCALVERSION is set, the user is using a git-based tree, and the
current HEAD is not referred to by any tags in .git/refs/tags/, append -g and
the first 8 characters of the commit to the version string. This makes it
easier to use git-bisect, and/or to do a daily build, without trampling on your
older, working builds, or accidentally setting up conflicting sets of modules.
Signed-off-by: Ryan Anderson <ryan@michonline.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Move initramfs options from Device Drivers | Block Drivers to General Setup
This is a more natural place for this option.
Furthermore separate out intramfs options to usr/Kconfig
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Minor cleanup.
Move things into their include files, remove obsolete includes, fix
indentation, remove obsolete special cases etc.
I also added the per cpu section to asm-generic/sections.h and fixed
init/main.c to use it.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add kerneldoc to kernel/cpuset.c
Fix cpuset typos in init/Kconfig
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
From: Matt Mackall <mpm@selenic.com>
Add PREEMPT to UTS_VERSION where enabled as is done for SMP to make
preempt kernels easily identifiable.
Added SMP PREEMPT as comment in compile.h to force it to be
updated when they change (sam).
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Remove ROOT_DEV after unexporting it in the previous patch, as requested time
ago by Christoph Hellwig.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
kernel/power/disk.c needs a declaration of name_to_dev_t() in scope. mount.h
seems like an appropriate choice.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
On system boot up, there was an failure reported to boot.msg:
<5>Trying to move old root to /initrd ... failed
According to initrd(4) man page, step #7 of BOOT-UP OPERATION
is described as below:
7. If the normal root file has directory /initrd, device
/dev/ram0 is moved from / to /initrd. Otherwise if
directory /initrd does not exist device /dev/ram0 is
unmounted.
We got service calls from customers concerning about this failure message
at boot time. Many systems do not have /initrd and thus the message can be
changed in the case of non-existing /initrd so that it does not sound like
a failure of the system.
Signed-off-by: Jay Lan <jlan@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch tweaks idle thread setup semantics a bit: instead of setting
NEED_RESCHED in init_idle(), we do an explicit schedule() before calling
into cpu_idle().
This patch, while having no negative side-effects, enables wider use of
cond_resched()s. (which might happen in the stock kernel too, but it's
particulary important for voluntary-preempt)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Issue:
Current tsc based delay_calibration can result in significant errors in
loops_per_jiffy count when the platform events like SMIs
(System Management Interrupts that are non-maskable) are present. This could
lead to potential kernel panic(). This issue is becoming more visible with 2.6
kernel (as default HZ is 1000) and on platforms with higher SMI handling
latencies. During the boot time, SMIs are mostly used by BIOS (for things
like legacy keyboard emulation).
Description:
The psuedocode for current delay calibration with tsc based delay looks like
(0) Estimate a value for loops_per_jiffy
(1) While (loops_per_jiffy estimate is accurate enough)
(2) wait for jiffy transition (jiffy1)
(3) Note down current tsc (tsc1)
(4) loop until tsc becomes tsc1 + loops_per_jiffy
(5) check whether jiffy changed since jiffy1 or not and refine
loops_per_jiffy estimate
Consider the following cases
Case 1:
If SMIs happen between (2) and (3) above, we can end up with a
loops_per_jiffy value that is too low. This results in shorted delays and
kernel can panic () during boot (Mostly at IOAPIC timer initialization
timer_irq_works() as we don't have enough timer interrupts in a specified
interval).
Case 2:
If SMIs happen between (3) and (4) above, then we can end up with a
loops_per_jiffy value that is too high. And with current i386 code, too
high lpj value (greater than 17M) can result in a overflow in
delay.c:__const_udelay() again resulting in shorter delay and panic().
Solution:
The patch below makes the calibration routine aware of asynchronous events
like SMIs. We increase the delay calibration time and also identify any
significant errors (greater than 12.5%) in the calibration and notify it to
user.
Patch below changes both i386 and x86-64 architectures to use this
new and improved calibrate_delay_direct() routine.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch modifies the way pagesets in struct zone are managed.
Each zone has a per-cpu array of pagesets. So any particular CPU has some
memory in each zone structure which belongs to itself. Even if that CPU is
not local to that zone.
So the patch relocates the pagesets for each cpu to the node that is nearest
to the cpu instead of allocating the pagesets in the (possibly remote) target
zone. This means that the operations to manage pages on remote zone can be
done with information available locally.
We play a macro trick so that non-NUMA pmachines avoid the additional
pointer chase on the page allocator fastpath.
AIM7 benchmark on a 32 CPU SGI Altix
w/o patches:
Tasks jobs/min jti jobs/min/task real cpu
1 484.68 100 484.6769 12.01 1.97 Fri Mar 25 11:01:42 2005
100 27140.46 89 271.4046 21.44 148.71 Fri Mar 25 11:02:04 2005
200 30792.02 82 153.9601 37.80 296.72 Fri Mar 25 11:02:42 2005
300 32209.27 81 107.3642 54.21 451.34 Fri Mar 25 11:03:37 2005
400 34962.83 78 87.4071 66.59 588.97 Fri Mar 25 11:04:44 2005
500 31676.92 75 63.3538 91.87 742.71 Fri Mar 25 11:06:16 2005
600 36032.69 73 60.0545 96.91 885.44 Fri Mar 25 11:07:54 2005
700 35540.43 77 50.7720 114.63 1024.28 Fri Mar 25 11:09:49 2005
800 33906.70 74 42.3834 137.32 1181.65 Fri Mar 25 11:12:06 2005
900 34120.67 73 37.9119 153.51 1325.26 Fri Mar 25 11:14:41 2005
1000 34802.37 74 34.8024 167.23 1465.26 Fri Mar 25 11:17:28 2005
with slab API changes and pageset patch:
Tasks jobs/min jti jobs/min/task real cpu
1 485.00 100 485.0000 12.00 1.96 Fri Mar 25 11:46:18 2005
100 28000.96 89 280.0096 20.79 150.45 Fri Mar 25 11:46:39 2005
200 32285.80 79 161.4290 36.05 293.37 Fri Mar 25 11:47:16 2005
300 40424.15 84 134.7472 43.19 438.42 Fri Mar 25 11:47:59 2005
400 39155.01 79 97.8875 59.46 590.05 Fri Mar 25 11:48:59 2005
500 37881.25 82 75.7625 76.82 730.19 Fri Mar 25 11:50:16 2005
600 39083.14 78 65.1386 89.35 872.79 Fri Mar 25 11:51:46 2005
700 38627.83 77 55.1826 105.47 1022.46 Fri Mar 25 11:53:32 2005
800 39631.94 78 49.5399 117.48 1169.94 Fri Mar 25 11:55:30 2005
900 36903.70 79 41.0041 141.94 1310.78 Fri Mar 25 11:57:53 2005
1000 36201.23 77 36.2012 160.77 1458.31 Fri Mar 25 12:00:34 2005
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Shobhit Dayal <shobhit@calsoftinc.com>
Signed-off-by: Shai Fultheim <Shai@Scalex86.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Actually, the real support was added by some earlier patches. Now we simply
re-enable the config. option. I've actually tested it and it works well.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Audit now actually requires netlink. So make it depend on CONFIG_NET,
and remove the inline dependencies on CONFIG_NET.
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
This patch is for -mm only. It should probably be included in git-audit,
and should be forwarded to Linus iff git-audit is.
It updates the audit-syscall-{entry,exit} calls to current -mm.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Arrange for all kernel printks to be no-ops. Only available if
CONFIG_EMBEDDED.
This patch saves about 375k on my laptop config and nearly 100k on minimal
configs.
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch eliminates all kernel BUGs, trims about 35k off the typical
kernel, and makes the system slightly faster.
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Linus Torvalds