Historically, Linux has tried to make the regular timer tick on the
various CPUs not happen at the same time, to avoid contention on
xtime_lock.
Nowadays, with the tickless kernel, this contention no longer happens
since time keeping and updating are done differently. In addition,
this skew is actually hurting power consumption in a measurable way on
many-core systems.
Signed-off-by: Arjan van de Ven <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
In order to diagnose overall suspend/resume times, we need
basic instrumentation to break down the total time into per
device timing, similar to initcall_debug.
This patch adds the basic timing instrumentation, needed
for a scritps/bootgraph.pl equivalent or humans.
The bootgraph.pl program is still a work in progress, but
is far enough along to know that this patch is sufficient.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
gcc is not convinced that the floppy.c ioctl has sufficient bound checks:
In function `copy_from_user',
inlined from `fd_copyin' at drivers/block/floppy.c:3080,
inlined from `fd_ioctl' at drivers/block/floppy.c:3503:
arch/x86/include/asm/uaccess_32.h:211:
warning: call to `copy_from_user_overflow' declared with attribute
warning: copy_from_user buffer size is not provably correct
And frankly, as a human I have a hard time proving the same more or less
(the size comes from the ioctl argument. humpf. maybe. the code isn't
very nice)
This patch adds an explicit check to make 100% sure it's safe, better than
finding out later that there indeed was a gap.
[[email protected]: add WARN_ON()]
Signed-off-by: Arjan van de Ven <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
There are reasons for kernel code to ask for, and use, performance
counters.
For example, in CPU freq governors this tends to be a good idea, but
there are other examples possible as well of course.
This patch adds the needed bits to do enable this functionality; they
have been tested in an experimental cpufreq driver that I'm working on,
and the changes are all that I needed to access counters properly.
[[email protected]: added pid to perf_event_create_kernel_counter so
that we can profile a particular task too
TODO: Have a better error reporting, don't just return NULL in fail
case.]
v2: Remove the wrong comment about the fact
perf_event_create_kernel_counter must be called from a kernel
thread.
Signed-off-by: Arjan van de Ven <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Cc: "K.Prasad" <[email protected]>
Cc: Alan Stern <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jan Kiszka <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Li Zefan <[email protected]>
Cc: Avi Kivity <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Paul Mundt <[email protected]>
Cc: Jan Kiszka <[email protected]>
Cc: Avi Kivity <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Frederic Weisbecker <[email protected]>
STACKPROTECTOR_ALL has a really high overhead (runtime and stack
footprint) and is not really worth it protection wise (the
normal STACKPROTECTOR is in effect for all functions with
buffers already), so lets just remove the option entirely.
Reported-by: Dave Jones <[email protected]>
Reported-by: Chuck Ebbert <[email protected]>
Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Eric Sandeen <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
During the Kernel Summit demo of perf/ftrace/timechart, there
was a feature request to have a process filter for timechart so
that you can zoom into one or a few processes that you are
really interested in.
This patch adds basic support for this feature, the -p
(--process) option now can select a PID or a process name to be
shown. Multiple -p options are allowed, and the combined set
will be included in the output.
Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
[from KS feedback]
Currently, scheduler delays are shown in a mostly transparent,
light yellow color. This color is rather hard to see on several
screens, especially projectors.
This patch changes the color of the scheduler delays to be a
much more "hard" yellow that survived the kernel summit
projector.
Reported-by: Linus Torvalds <[email protected]>
Signed-off-by: Arjan van de Ven <[email protected]
Cc: Peter Zijlstra <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
The timechart wakeup arrows currently show no process
information when the waker/wakee are processes that are not
actually chosen to be shown on the timechart.
This patch fixes this oversight, by looking through all
processes (after giving preference to visible processes) as well
as falling back to just showing the PID if no name for the
process can be resolved.
Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
The capabilities syscall has a copy_from_user() call where gcc currently
cannot prove to itself that the copy is always within bounds.
This patch adds a very explicity bound check to prove to gcc that this
copy_from_user cannot overflow its destination buffer.
Signed-off-by: Arjan van de Ven <[email protected]>
Acked-by: James Morris <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: James Morris <[email protected]>
The branch profiling creates very complex code for each if
statement, to the point that gcc has trouble even analyzing
something as simple as
if (count > 5)
count = 5;
This then means that causing an error on code that gcc cannot
analyze for copy_from_user() and co is not very productive.
This patch excludes the strict copy checks in the case of branch
profiling being enabled.
Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Steven Rostedt <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
MTRR and PAT support (which got added to CPUs over 10 years ago)
are no longer really optional in that more and more things are
depending on PAT just working, including various drivers and newer
versions of X. (to not even speak of MTRR)
Having this as a regular config option just no longer makes sense.
This patch relegates CONFIG_X86_PAT to the EMBEDDED category so
ultra-embedded can still disable it if they really need to.
Also-Suggested-by: Roland Dreier <[email protected]>
Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Henrique de Moraes Holschuh <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Now that range timers and deferred timers are common, I found a
problem with these using the "perf timechart" tool. Frans Pop also
reported high scheduler latencies via LatencyTop, when using
iwlagn.
It turns out that on x86, these two 'opportunistic' timers only get
checked when another "real" timer happens. These opportunistic
timers have the objective to save power by hitchhiking on other
wakeups, as to avoid CPU wakeups by themselves as much as possible.
The change in this patch runs this check not only at timer
interrupts, but at all (device) interrupts. The effect is that:
1) the deferred timers/range timers get delayed less
2) the range timers cause less wakeups by themselves because
the percentage of hitchhiking on existing wakeup events goes up.
I've verified the working of the patch using "perf timechart", the
original exposed bug is gone with this patch. Frans also reported
success - the latencies are now down in the expected ~10 msec
range.
Signed-off-by: Arjan van de Ven <[email protected]>
Tested-by: Frans Pop <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Mike Galbraith <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
sfi_verify_table() is called at runtime, and thus cannot be __init
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Len Brown <[email protected]>
The current bound checks for copy_from_user in the MTRR driver are
not as obvious as they could be, and gcc agrees with that.
This patch simplifies the boundary checks to the point that gcc can
now prove to itself that the copy_from_user() is never going past
its bounds.
Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Yinghai Lu <[email protected]>
Cc: Linus Torvalds <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
For automated testing it is useful to have the option to turn
the warnings on copy_from_user() etc checks into errors:
In function ‘copy_from_user’,
inlined from ‘fd_copyin’ at drivers/block/floppy.c:3080,
inlined from ‘fd_ioctl’ at drivers/block/floppy.c:3503:
linux/arch/x86/include/asm/uaccess_32.h:213:
error: call to ‘copy_from_user_overflow’ declared with attribute error:
copy_from_user buffer size is not provably correct
Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Andrew Morton <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
A previous patch added the buffer size check to copy_from_user().
One of the things learned from analyzing the result of the previous
patch is that in general, gcc is really good at proving that the
code contains sufficient security checks to not need to do a
runtime check. But that for those cases where gcc could not prove
this, there was a relatively high percentage of real security
issues.
This patch turns the case of "gcc cannot prove" into a compile time
warning, as long as a sufficiently new gcc is in use that supports
this. The objective is that these warnings will trigger developers
checking new cases out before a security hole enters a linux kernel
release.
Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: James Morris <[email protected]>
Cc: Jan Beulich <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
cmpxchg64() today generates, to quote Linus, "barf bag" code.
cmpxchg64() is about to get used in the scheduler to fix a bug there,
but it's a prerequisite that cmpxchg64() first be made non-sucking.
This patch turns cmpxchg64() into an efficient implementation that
uses the alternative() mechanism to just use the raw instruction on
all modern systems.
Note: the fallback is NOT smp safe, just like the current fallback
is not SMP safe. (Interested parties with i486 based SMP systems
are welcome to submit fix patches for that.)
Signed-off-by: Arjan van de Ven <[email protected]>
Acked-by: Linus Torvalds <[email protected]>
[ fixed asm constraint bug ]
Fixed-by: Eric Dumazet <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: John Stultz <[email protected]>
Cc: Peter Zijlstra <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
GCC provides reasonable memset/memcpy functions itself, with __builtin_memset
and __builtin_memcpy. For the "unknown" cases, it'll fall back to our
current existing functions, but for fixed size versions it'll inline
something smart. Quite often that will be the same as we have now,
but sometimes it can do something smarter (for example, if the code
then sets the first member of a struct, it can do a shorter memset).
In addition, and this is more important, gcc knows which registers and
such are not clobbered (while for our asm version it pretty much
acts like a compiler barrier), so for various cases it can avoid reloading
values.
The effect on codesize is shown below on my typical laptop .config:
text data bss dec hex filename
5605675 2041100 6525148 14171923 d83f13 vmlinux.before
5595849 2041668 6525148 14162665 d81ae9 vmlinux.after
Due to some not-so-good behavior in the gcc 3.x series, this change
is only done for GCC 4.x and above.
Signed-off-by: Arjan van de Ven <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>
gcc (4.x) supports the __builtin_object_size() builtin, which
reports the size of an object that a pointer point to, when known
at compile time. If the buffer size is not known at compile time, a
constant -1 is returned.
This patch uses this feature to add a sanity check to
copy_from_user(); if the target buffer is known to be smaller than
the copy size, the copy is aborted and a WARNing is emitted in
memory debug mode.
These extra checks compile away when the object size is not known,
or if both the buffer size and the copy length are constants.
Signed-off-by: Arjan van de Ven <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Fix the menu idle governor which balances power savings, energy efficiency
and performance impact.
The reason for a reworked governor is that there have been serious
performance issues reported with the existing code on Nehalem server
systems.
To show this I'm sure Andrew wants to see benchmark results:
(benchmark is "fio", "no cstates" is using "idle=poll")
no cstates current linux new algorithm
1 disk 107 Mb/s 85 Mb/s 105 Mb/s
2 disks 215 Mb/s 123 Mb/s 209 Mb/s
12 disks 590 Mb/s 320 Mb/s 585 Mb/s
In various power benchmark measurements, no degredation was found by our
measurement&diagnostics team. Obviously a small percentage more power was
used in the "fio" benchmark, due to the much higher performance.
While it would be a novel idea to describe the new algorithm in this
commit message, I cheaped out and described it in comments in the code
instead.
[changes since first post: spelling fixes from akpm, review feedback,
folded menu-tng into menu.c]
Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Venkatesh Pallipadi <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Yanmin Zhang <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
The "end of a C state" trace point currently happens before
the code runs that corrects the TSC for having stopped during idle.
The result of this is that the timestamp of the end-of-C-state event
is garbage on cpus where the TSC stops during idle.
This patch moves the end point of the C state to after the timekeeping
engine of the kernel has been corrected.
Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Len Brown <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: Paul Mackerras <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Be more consistent in the svghelper about the minimum text size
by having a global #define for this.
There needs to be a minimum text size in order to keep the size
of the SVG file within the reach of what current SVG viewers can
cope with.
Signed-off-by: Arjan van de Ven <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: Paul Mackerras <[email protected]>
Cc: Arjan van de Ven <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
This patch turns on parallel scanning for the ata_piix driver.
This driver is used on most netbooks (no AHCI for cheap storage it seems).
The scan is the dominating time factor in the kernel boot for these
devices; with this flag it gets cut in half for the device I used
for testing (eeepc).
Alan took a look at the driver source and concluded that it ought to be safe
to do for this driver. Alan has also checked with the hardware team.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Alan Cox <[email protected]>
Signed-off-by: Jeff Garzik <[email protected]>
There is no need to issue serialize_rcu() after adding a new handle
to the list of handles associated with the device because new events
will "see" the new handle in the list immediately. Remove it so we
can boot a little bit faster.
Signed-off-by: Dmitry Torokhov <[email protected]>
Andrew had some suggestions for the latencytop file; this patch takes care
of most of these:
* Add documentation
* Turn account_scheduler_latency into an inline function
* Don't report negative values to userspace
* Make the file operations struct const
* Fix a few checkpatch.pl warnings
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Without frame pointers enabled, the x86 stack traces should not
pretend to be reliable; instead they should just be what they are:
unreliable.
The effect of this is that they have a '?' printed in the stacktrace,
to warn the reader that these entries are guesses rather than known
based on more reliable information.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
We're struggling all the time to figure out where the code came from that
oopsed.. The script below (a adaption from a script used by
kerneloops.org) can help developers quite a bit, at least for non-module
cases.
It works and looks like this:
[/home/arjan/linux]$ dmesg | perl scripts/markup_oops.pl vmlinux
{
struct agp_memory *memory;
memory = agp_allocate_memory(agp_bridge, pg_count, type);
c055c10f: 89 c2 mov %eax,%edx
if (memory == NULL)
c055c111: 74 19 je c055c12c <agp_allocate_memory_wrap+0x30>
/* This function must only be called when current_controller != NULL */
static void agp_insert_into_pool(struct agp_memory * temp)
{
struct agp_memory *prev;
prev = agp_fe.current_controller->pool;
c055c113: a1 ec dc 8f c0 mov 0xc08fdcec,%eax
*c055c118: 8b 40 10 mov 0x10(%eax),%eax <----- faulting instruction
if (prev != NULL) {
c055c11b: 85 c0 test %eax,%eax
c055c11d: 74 05 je c055c124 <agp_allocate_memory_wrap+0x28>
prev->prev = temp;
c055c11f: 89 50 04 mov %edx,0x4(%eax)
temp->next = prev;
c055c122: 89 02 mov %eax,(%edx)
}
agp_fe.current_controller->pool = temp;
c055c124: a1 ec dc 8f c0 mov 0xc08fdcec,%eax
c055c129: 89 50 10 mov %edx,0x10(%eax)
if (memory == NULL)
return NULL;
agp_insert_into_pool(memory);
so in this case, we faulted while dereferencing agp_fe.current_controller
pointer, and we get to see exactly which function and line it affects...
Personally I find this very useful, and I can see value for having this
script in the kernel for more-than-just-me to use.
Caveats:
* It only works for oopses not-in-modules
* It only works nicely for kernels compiled with CONFIG_DEBUG_INFO
* It's not very fast.
* It only works on x86
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Explain that you really need to use the return value of d_path rather than
the buffer you passed into it.
Also fix the comment for seq_path(), the function arguments changed
recently but the comment hadn't been updated in sync.
Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Al Viro <[email protected]>
Impact: new "power-tracer" ftrace plugin
This patch adds a C/P-state ftrace plugin that will generate
detailed statistics about the C/P-states that are being used,
so that we can look at detailed decisions that the C/P-state
code is making, rather than the too high level "average"
that we have today.
An example way of using this is:
mount -t debugfs none /sys/kernel/debug
echo cstate > /sys/kernel/debug/tracing/current_tracer
echo 1 > /sys/kernel/debug/tracing/tracing_enabled
sleep 1
echo 0 > /sys/kernel/debug/tracing/tracing_enabled
cat /sys/kernel/debug/tracing/trace | perl scripts/trace/cstate.pl > out.svg
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
ml_ff_playback() uses spin_(un)lock_bh. However this function is
called with interrupts disabled from erase_effect() in
drivers/input/ff-core.c:196.
This is not permitted, and will result in a WARN_ON in the bottom
half handling code. This patch changes this function to just use
spin_lock_irqsave() instead, solving the problem and simplifying
the locking logic.
This was reported as entry #106559 in kerneloops.org
Reported-by: kerneloops.org
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Dmitry Torokhov <[email protected]>
kunmap() takes as argument the struct page that orginally got kmap()'d,
however the sg_miter_stop() function passed it the kernel virtual address
instead, resulting in weird stuff.
Somehow I ended up fixing this bug by accident while looking for a bug in
the same area.
Reported-by: kerneloops.org
Acked-by: Tejun Heo <[email protected]>
Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: <[email protected]> [2.6.27.x]
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Use the newly introduced pci_ioremap_bar() function in drivers/net.
pci_ioremap_bar() just takes a pci device and a bar number, with the goal
of making it really hard to get wrong, while also having a central place
to stick sanity checks.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Jeff Garzik <[email protected]>
Impact: cleanup
now that the code is moved and converted to a work queue,
there's some minor cleanups that can be done.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Impact: change the implementation of the debug feature
the periodic corruption checks are better off run from a work queue; there's
nothing time critical about them and this way the amount of
interrupt-context work is reduced.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Hi Al,
remember that debug session we did at KS? You suggested this patch back
then....
From 7751eaf30474b8cbfaea64795805a17eab05ac53 Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <[email protected]>
Date: Tue, 16 Sep 2008 16:51:17 -0700
Subject: [PATCH] fs: add a sanity check in d_free
we're seeing some corruption in the dentry->d_alias list that
appears like a free of an entry still on the list; this patch
adds a WARN_ON() to catch this scenario, as suggested by Al Viro
Signed-off-by: Arjan van de Ven <[email protected]>
Use the newly introduced pci_ioremap_bar() function in drivers/i2c.
pci_ioremap_bar() just takes a pci device and a bar number, with the goal
of making it really hard to get wrong, while also having a central place
to stick sanity checks.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Jean Delvare <[email protected]>
A common thing in many PCI drivers is to ioremap() an entire bar. This
is a slightly fragile thing right now, needing both an address and a
size, and many driver writers do.. various things there.
This patch introduces an pci_ioremap() function taking just a PCI device
struct and the bar number as arguments, and figures this all out itself,
in one place. In addition, we can add various sanity checks to this
function (the patch already checks to make sure that the bar in question
really is a MEM bar; few to no drivers do that sort of thing).
Hopefully with this type of API we get less chance of mistakes in
drivers with ioremap() operations.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Jesse Barnes <[email protected]>
When printing nanoseconds, the right printk format string is %09 not %06...
Signed-off-by: Arjan van de Ven <[email protected]>
Acked-by: Frédéric Weisbecker <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
there's several drivers that have use "tx_timeout" for the .. tx
timeout function. All fine with that, they're static, however for
doing stats on how often which driver hits the timeout it's a tad
unfortunate. The patch below gives the ones I found in the
kerneloops.org database unique names.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
With the new firmware infrastructure in 2.6.27, some files are generated and shouldn't be
diffed; add these 2 to the "dontdiff" file
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Latest update; I now have 4 NX tests, but 2 fail so they're #if 0'd.
I also cleaned up the NX test code quite a bit, and got rid of the ugly
exception table sorting stuff.
From: Arjan van de Ven <[email protected]>
This patch adds testcases for the CONFIG_DEBUG_RODATA configuration option
as well as the NX CPU feature/mappings. Both testcases can move to tests/
once that patch gets merged into mainline.
(I'm half considering moving the rodata test into mm/init.c but I'll
wait with that until init.c is unified)
As part of this I had to fix a not-quite-right alignment in the vmlinux.lds.h
for the RODATA sections, which lead to 1 page less being marked read only.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
With the introduction of the new API, no driver or non-archcore code needs
to use c-p-a anymore, so this patch also deprecates the EXPORT_SYMBOL of CPA
(it's a horrible API after all).
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
This patch converts various users of change_page_attr() to the new,
more intent driven set_page_*/set_memory_* API set.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Right now, if drivers or other code want to change, say, a cache attribute of a
page, the only API they have is change_page_attr(). c-p-a is a really bad API
for this, because it forces the caller to know *ALL* the attributes he wants
for the page, not just the 1 thing he wants to change. So code that wants to
set a page uncachable, needs to be aware of the NX status as well etc etc etc.
This patch introduces a set of new APIs for this, set_pages_<attr> and
set_memory_<attr>, that offer a logical change to the user, and leave all
attributes not implied by the requested logical change alone.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
During the work on the x86 32 and 64 bit backtrace code I found it useful
to have a simple test module to test a process and irq context backtrace.
Since the existing backtrace code was buggy, I figure it might be useful
to have such a test module in the kernel so that maybe we can even
detect such bugs earlier..
[ [email protected]: build fix ]
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
A quick grep shows that there are currently 1145 instances of WARN_ON
in the kernel. Currently, WARN_ON is pretty much entirely inlined,
which makes it hard to enhance it without growing the size of the kernel
(and getting Andrew unhappy).
This patch build on top of Olof's patch that introduces __WARN,
and places the slowpath out of line. It also uses Ingo's suggestion
to not use __FUNCTION__ but to use kallsyms to do the lookup;
this saves a ton of extra space since gcc doesn't need to store the function
string twice now:
3936367 833603 624736 5394706 525112 vmlinux.before
3917508 833603 624736 5375847 520767 vmlinux-slowpath
15Kb savings...
Signed-off-by: Arjan van de Ven <[email protected]>
CC: Andrew Morton <[email protected]>
CC: Olof Johansson <[email protected]>
Acked-by: Matt Meckall <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
The latest Intel processors (the 45nm ones) have a model number of 23
(old ones had 15); they're otherwise compatible on the oprofile side.
This patch adds the new model number to the oprofile code.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
This patch modifies the USB regular 250ms timer to be "perfectly aligned" to
the second and quarters thereof. This change is there to make sure that if
you have multiple USB ports, the timers for all these ports will fire at the
same time rather than all spread out. All spread out wakes the CPU up from
power saving idle a lot more than needed...
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Do not mark the kernel text read only if KPROBES is in the kernel;
kprobes needs to hot-patch the kernel text to insert it's
instrumentation.
In this case, only mark the .rodata segment as read only.
Signed-off-by: Arjan van de Ven <[email protected]>
Tested-by: S. P. Prasanna <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: William Cohen <[email protected]>
Cc: Ian McDonald <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
The 8390 drivers use disable_irq() as a locking primitive, which means these
uses need lockdep specific annotation that they are used as such.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Jeff Garzik <[email protected]>
mm/slab.c uses nested locking when dealing with 'off-slab'
caches, in that case it allocates the slab header from the
(on-slab) kmalloc caches. Teach the lock validator about
this by putting all on-slab caches into a separate class.
this patch has no effect on non-lockdep kernels.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
{un}register_die_notifier() is used by kdb... document this so that future
"remove dead export" rounds can skip this export.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
> stack backtrace:
> [<f9099d31>] rtl8139_start_xmit+0xd9/0xff [8139too]
> [<c11ad5ea>] netpoll_send_skb+0x98/0xea
This seems to be a real deadlock...
So netpoll_send_skb takes the _xmit_lock, which is all nitty gritty
but then rtl8139_start_xmit comes around while that lock is taken, and
does
spin_unlock_irq(&tp->lock);
which.. enables interrupts and softirqs; this is quite bad because the
xmit lock is taken in softirq context for the watchdog like this:
[<c1200376>] _spin_lock+0x23/0x32
[<c11af282>] dev_watchdog+0x14/0xb1
[<c101dab2>] run_timer_softirq+0xf2/0x14a
[<c101a691>] __do_softirq+0x55/0xb0
[<c1004a8d>] do_softirq+0x58/0xbd
Which would deadlock now that the spin_unlock_irq() has enabled
irqs/softirqs while the _xmit_lock is still held.
The patch below turns this into a irqsave/irqrestore pair so that
interrupts don't get enabled unconditionally.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Jeff Garzik <[email protected]>
There is a code sequence where the locking is substream->self_group.lock
-> ins->scbs[index].lock
substream->self_group.lock is interrupt safe, and taken from irq context
as well (trace is snipped for brevity)
so what can happen is
cpu 0 cpu 1
user context user context
take ins->scbs[index].lock without disabling interrupts
get substream->self_group.lock (irqsafe)
try to get ins->scbs[index].lock (spins)
interrupt happens
try to get substream->self_group.lock (spins)
which is an obvious AB-BA deadlock
fix is to just take the lock with _irqsafe
Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Jaroslav Kysela <[email protected]>
Acked-by: Takashi Iwai <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
On Fri, 2006-06-30 at 15:45 -0700, Miles Lane wrote:
> Okay, I rebuilt my kernel with your combo patch applied.
> Then, I inserted my US Robotics USR2210 PCMCIA wifi card,
> ran "pccardutil eject", popped out the card and then inserted
> a Compaq iPaq wifi card. This triggered the following.
>
> [ INFO: possible circular locking dependency detected ]
> -------------------------------------------------------
> syslogd/1886 is trying to acquire lock:
> (&dev->queue_lock){-+..}, at: [<c11a50b5>] dev_queue_xmit+0x120/0x24b
>
> but task is already holding lock:
> (&dev->_xmit_lock){-+..}, at: [<c11a5118>] dev_queue_xmit+0x183/0x24b
>
> which lock already depends on the new lock.
ok this appears to be hostap playing games... it has 2 network devices
for one piece of hardware and one calls the other via the networking
layer; there is thankfully a natural ordering between the two, so just
making the slave one a separate type ought to make this work.
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Arjan van de Ven <[email protected]>
Cc: "John W. Linville" <[email protected]>
Cc: Jeff Garzik <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
The s_umount rwsem needs to be classified as per-superblock since it's
perfectly legit to keep multiple of those recursively in the VFS locking
rules.
Has no effect on non-lockdep kernels.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Add i_mutex ordering annotations to the sunrpc rpc_pipe code. This code has 3
levels of i_mutex hierarchy in some cases: parent dir, client dir and file
inside client dir; the i_mutex ordering is I_MUTEX_PARENT -> I_MUTEX_CHILD ->
I_MUTEX_NORMAL
This patch applies this ordering annotation to the various functions. This is
in line with the VFS expected ordering where it is always OK to lock a child
after locking a parent; the sunrpc code is very diligent in doing this
correctly.
Has no effect on non-lockdep kernels.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Trond Myklebust <[email protected]>
Cc: Neil Brown <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Mark the static struct file_operations in drivers/char as const. Making
them const prevents accidental bugs, and moves them to the .rodata section
so that they no longer do any false sharing; in addition with the proper
debug option they are then protected against corruption..
[[email protected]: build fix]
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
reported by Jure Repinc:
> > http://bugzilla.kernel.org/show_bug.cgi?id=6773
> > checked out dmesg output and found the message
> >
> > ======================================================
> > [ BUG: hard-safe -> hard-unsafe lock order detected! ]
> > ------------------------------------------------------
> >
> > starting at line 660 of the dmesg.txt that I will attach.
The patch below should fix the deadlock, albeit I suspect it's not the
"right" fix; the right fix may well be to move the rx processing in bcm43xx
to softirq context. [it's debatable, ipw2200 hit this exact same bug; at
some point it's better to bite the bullet and move this to the common layer
as my patch below does]
Make the nl_table_lock irq-safe; it's taken for read in various netlink
functions, including functions that several wireless drivers (ipw2200,
bcm43xx) want to call from hardirq context.
The deadlock was found by the lock validator.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>
Cc: Michael Buesch <[email protected]>
Cc: "John W. Linville" <[email protected]>
Cc: Jeff Garzik <[email protected]>
Acked-by: "David S. Miller" <[email protected]>
Cc: jamal <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
From: Arjan van de Ven <[email protected]>
Convert the semaphores-used-as-mutex to mutexes in the sisusb video driver;
this required manual checking due to the "return as locked" stuff in this
driver, but the ->lock semaphore is still used as mutex in the end.
Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Thomas Winischhofer <winischhofer.net>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Len Brown <[email protected]>
This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups
The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Mark the f_ops members of inodes as const, as well as fix the
ripple-through this causes by places that copy this f_ops and then "do
stuff" with it.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Neil Brown <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This patch puts the infrastructure in place to allow for a reordering of
functions based inside the vmlinux. The general idea is that it is possible
to put all "common" functions into the first 2Mb of the code, so that they
are covered by one TLB entry. This as opposed to the current situation where
a typical vmlinux covers about 3.5Mb (on x86-64) and thus 2 TLB entries.
This is done by enabling the -ffunction-sections flag in gcc, which puts
each function in its own ELF section, so that the linker can then order them
in a way defined by the linker script.
As per previous discussions, Linus said he wanted a "static" list for this,
eg a list provided by the kernel tarbal, so that most people have the same
ordering at least. A script is provided to create this list based on
readprofile(1) output. The included list is provisional, and entirely biased
on my own testbox and me running a few kernel compiles and some other
things.
I think that to get to a better list we need to invite people to submit
their own profiles, and somehow add those all up and base the final list on
that. I'm willing to do that effort if this is ends up being the prefered
approach. Such an effort probably needs to be repeated like once a year or
so to adopt to the changing nature of the kernel.
Made it a CONFIG with default n because it increases link times
dramatically.
Signed-off-by: Andi Kleen <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
The patch below converts a few i2c semaphores to mutexes
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
The fat code uses the fat_lock always in a mutex way (taking and releasing
the lock in the same function), the patch below converts it into the new
mutex primitive. Please consider this patch for the code.
Signed-off-by: Arjan van de Ven <[email protected]>
Acked-by: OGAWA Hirofumi <[email protected]>
Cc: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Bartlomiej Zolnierkiewicz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
ext3's truncate_sem is always released in the same function it's taken
and it otherwise is a mutex as well..
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Davide Libenzi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Jens Axboe <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Karsten Keil <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
the patch below converts a bunch of semaphores-used-as-mutex in the USB
code to mutexes
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Dmitry Torokhov <[email protected]>
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Dmitry Torokhov <[email protected]>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Mark Fasheh <[email protected]>
This is the usbatm part of the Arjan, Jes and Ingo
mass semaphore to mutex conversion, reworked to apply on top
of the patches I just sent to you. This time, with correct
attribution and signed-off lines.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Duncan Sands <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
This one fell through the automation at first because it initializes the
semaphore to locked, but that's easily remedied
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Dave Jones <[email protected]>
drivers/cpufreq/cpufreq.c | 37 +++++++++++++++++++------------------
include/linux/cpufreq.h | 3 ++-
2 files changed, 21 insertions(+), 19 deletions(-)
Mark a few VFS functions as mandatory inline (based on Al Viro's request);
these must be inline due to stack usage issues during a recursive loop that
happens during the recursive symlink resolution (symlink to a symlink to a
symlink ..)
This patch at this point does not change behavior and is for documentation
purposes only (but this changes later in the series)
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Remove the "inline" keyword from a bunch of big functions in the kernel with
the goal of shrinking it by 30kb to 40kb
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Jeff Garzik <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Turn several drivers/serial/ semaphores-used-as-mutex into mutexes
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Russell King <[email protected]>
The arm clock semaphores are strict mutexes, convert them to the new
mutex implementation
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Russell King <[email protected]>
the scsi layer is using semaphores in a mutex way, this patch converts
these into using mutexes instead
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: James Bottomley <[email protected]>
Avoid doing assignments to a live ->fops so it can be marked as 'const'.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Dmitry Torokhov <[email protected]>
add the per-arch mutex.h files for the remaining architectures.
We default to asm-generic/mutex-dec.h, because that performs
quite well on most arches. Arches that do not have atomic
decrement/increment instructions should switch to mutex-xchg.h
instead. Arches can also provide their own implementation for
the mutex fastpath primitives.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Arjan van de Ven