Commit Graph
55 Commits
Author SHA1 Message Date
Arjan van de Ven c5ef1c42c5 [PATCH] mark struct inode_operations const 3
Many struct inode_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2007-02-12 09:48:46 -08:00
Arjan van de Ven 92e1d5be91 [PATCH] mark struct inode_operations const 2
Many struct inode_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2007-02-12 09:48:46 -08:00
Arjan van de Ven 754661f143 [PATCH] mark struct inode_operations const 1
Many struct inode_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2007-02-12 09:48:46 -08:00
Arjan van de Ven 9c2e08c592 [PATCH] mark struct file_operations const 9
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2007-02-12 09:48:46 -08:00
Arjan van de Ven da7071d7e3 [PATCH] mark struct file_operations const 8
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2007-02-12 09:48:46 -08:00
Arjan van de Ven 9a32144e9d [PATCH] mark struct file_operations const 7
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2007-02-12 09:48:46 -08:00
Arjan van de Ven 00977a59b9 [PATCH] mark struct file_operations const 6
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2007-02-12 09:48:45 -08:00
Arjan van de Ven d54b1fdb1d [PATCH] mark struct file_operations const 5
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2007-02-12 09:48:45 -08:00
Arjan van de Ven fa027c2a0a [PATCH] mark struct file_operations const 4
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

[[email protected]: dvb fix]
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2007-02-12 09:48:45 -08:00
Arjan van de Ven 2b8693c061 [PATCH] mark struct file_operations const 3
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2007-02-12 09:48:45 -08:00
Arjan van de Ven 5dfe4c964a [PATCH] mark struct file_operations const 2
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

[[email protected]: sparc64 fix]
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2007-02-12 09:48:44 -08:00
Arjan van de Ven 540473208f [PATCH] mark struct file_operations const 1
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2007-02-12 09:48:44 -08:00
Arjan van de Ven 7a44e910f4 [PATCH] user of the jiffies rounding patch: ATA subsystem
This patch introduces users of the round_jiffies() function: ATA subsystem

This delayed work is of the "about once a second" variety and can be rounded
to coincide with other wakers.

Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Jeff Garzik <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Jeff Garzik <[email protected]>
2007-02-09 17:39:29 -05:00
Arjan van de Ven f5a6e01c09 [NET]: user of the jiffies rounding code: Networking
This patch introduces users of the round_jiffies() function in the
networking code.

These timers all were of the "about once a second" or "about once
every X seconds" variety and several showed up in the "what wakes the
cpu up" profiles that the tickless patches provide.  Some timers are
highly dynamic based on network load; but even on low activity systems
they still show up so the rounding is done only in cases of low
activity, allowing higher frequency timers in the high activity case.

The various hardware watchdogs are an obvious case; they run every 2
seconds but aren't otherwise specific of exactly when they need to
run.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
2007-02-08 12:38:52 -08:00
Arjan van de Ven 1d39ed565c remove NETIF_F_TSO ifdefery
Remove the NETIF_F_TSO #ifdef-ery in drivers/net; this was
for old-old-2.4 compat (even current 2.4 has NETIF_F_TSO)
but it's time to get rid of it by now.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Jeff Garzik <[email protected]>
2007-02-05 16:58:45 -05:00
Arjan van de Ven 2b2842146c [PATCH] user of the jiffies rounding patch: Slab
This patch introduces users of the round_jiffies() function in the slab code.

The slab code has a few "run every second" timers for background work; these
are obviously not timing critical as long as they happen roughly at the right
frequency.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-12-10 09:57:22 -08:00
Arjan van de Ven 44d306e150 [PATCH] user of the jiffies rounding code: JBD
This patch introduces a user: of the round_jiffies() function; the "5 second"
ext3/jbd wakeup.

While "every 5 seconds" doesn't sound as a problem, there can be many of these
(and these timers do add up over all the kernel).  The "5 second" wakeup isn't
really timing sensitive; in addition even with rounding it'll still happen
every 5 seconds (with the exception of the very first time, which is likely to
be rounded up to somewhere closer to 6 seconds)

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-12-10 09:57:22 -08:00
Arjan van de Ven 4c36a5dec2 [PATCH] round_jiffies infrastructure
Introduce a round_jiffies() function as well as a round_jiffies_relative()
function.  These functions round a jiffies value to the next whole second.
The primary purpose of this rounding is to cause all "we don't care exactly
when" timers to happen at the same jiffy.

This avoids multiple timers firing within the second for no real reason;
with dynamic ticks these extra timers cause wakeups from deep sleep CPU
sleep states and thus waste power.

The exact wakeup moment is skewed by the cpu number, to avoid all cpus from
waking up at the exact same time (and hitting the same lock/cachelines
there)

[[email protected]: fix variable type]
Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-12-10 09:57:22 -08:00
Arjan van de Ven 2e591bbc0d [PATCH] Make initramfs printk a warning on incorrect cpio type
It turns out that the "-c" option of cpio is highly unportable even between
distros let alone unix variants, and may actually make the wrong type of
cpio archive.  I just wasted quite some time on this, and the kernel can
detect this and warn about it (it's __init memory so it gets thrown away
and thus there is no runtime overhead)

Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Al Viro <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-12-07 08:39:36 -08:00
Arjan van de Ven f3d73707a1 [PATCH] x86-64: Mark rdtsc as sync only for netburst, not for core2
On the Core2 cpus, the rdtsc instruction is not serializing (as defined
in the architecture reference since rdtsc exists) and due to the deep
speculation of these cores, it's possible that you can observe time go
backwards between cores due to this speculation. Since the kernel
already deals with this with the SYNC_RDTSC flag, the solution is
simple, only assume that the instruction is serializing on family 15...

The price one pays for this is a slightly slower gettimeofday (by a
dozen or two cycles), but that increase is quite small to pay for a
really-going-forward tsc counter.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andi Kleen <[email protected]>
2006-12-07 02:14:12 +01:00
Arjan van de Ven cfd3ef2346 [PATCH] lockdep: spin_lock_irqsave_nested()
Introduce spin_lock_irqsave_nested(); implementation from:
 http://lkml.org/lkml/2006/6/1/122
Patch from:
 http://lkml.org/lkml/2006/9/13/258

[[email protected]: two compile fixes]
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-11-25 13:28:34 -08:00
Arjan van de Ven d654c673d6 [PATCH] Regression in 2.6.19-rc microcode driver
If the microcode driver is built in (rather than module) there are some,
ehm, interesting effects happening due to the new "call out to userspace"
behavior that is introduced..  and which runs too early.  The result is a
boot hang; which is really nasty.

The patch below is a minimally safe patch to fix this regression for 2.6.19
by just not requesting actual microcode updates during early boot.  (That
is a good idea in general anyway)

The "real" fix is a lot more complex given the entire cpu hotplug scenario
(during cpu hotplug you normally need to load the microcode as well); but
the interactions for that are just really messy at this point; this fix at
least makes it work and avoids a full detangle of hotplug.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-11-08 18:29:22 -08:00
Arjan van de Ven 5c87579e65 [PATCH] maximum latency tracking infrastructure
Add infrastructure to track "maximum allowable latency" for power saving
policies.

The reason for adding this infrastructure is that power management in the
idle loop needs to make a tradeoff between latency and power savings
(deeper power save modes have a longer latency to running code again).  The
code that today makes this tradeoff just does a rather simple algorithm;
however this is not good enough: There are devices and use cases where a
lower latency is required than that the higher power saving states provide.
 An example would be audio playback, but another example is the ipw2100
wireless driver that right now has a very direct and ugly acpi hook to
disable some higher power states randomly when it gets certain types of
error.

The proposed solution is to have an interface where drivers can

* announce the maximum latency (in microseconds) that they can deal with
* modify this latency
* give up their constraint

and a function where the code that decides on power saving strategy can
query the current global desired maximum.

This patch has a user of each side: on the consumer side, ACPI is patched
to use this, on the producer side the ipw2100 driver is patched.

A generic maximum latency is also registered of 2 timer ticks (more and you
lose accurate time tracking after all).

While the existing users of the patch are x86 specific, the infrastructure
is not.  I'd like to ask the arch maintainers of other architectures if the
infrastructure is generic enough for their use (assuming the architecture
has such a tradeoff as concept at all), and the sound/multimedia driver
owners to look at the driver facing API to see if this is something they
can use.

[[email protected]: cleanups]
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Jesse Barnes <[email protected]>
Cc: "Brown, Len" <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-10-01 00:39:19 -07:00
Arjan van de Ven e8106b941c [PATCH] lockdep: core, add enable/disable_irq_irqsave/irqrestore() APIs
Introduce the disable_irq_nosync_lockdep_irqsave() and
enable_irq_lockdep_irqrestore() APIs.  These are needed for NE2000; basically
NE2000 calls disable_irq and enable_irq as locking against the IRQ handler,
but both in cases where interrupts are on and off.  This means that lockdep
needs to track the old state of the virtual irq flags on disable_irq, and
restore these at enable_irq time.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Jeff Garzik <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-09-29 09:18:20 -07:00
Arjan van de Ven 4f7fd4d7a7 [PATCH] Add the -fstack-protector option to the CFLAGS
Add a feature check that checks that the gcc compiler has stack-protector
support and has the bugfix for PR28281 to make this work in kernel mode.
The easiest solution I could find was to have a shell script in scripts/
to do the detection; if needed we can make this fancier in the future
without making the makefile too complex.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andi Kleen <[email protected]>
CC: Andi Kleen <[email protected]>
CC: Sam Ravnborg <[email protected]>
2006-09-26 10:52:39 +02:00
Arjan van de Ven 3162f751d0 [PATCH] Add the __stack_chk_fail() function
GCC emits a call to a __stack_chk_fail() function when the stack canary is
not matching the expected value.

Since this is a bad security issue; lets panic the kernel rather than limping
along; the kernel really can't be trusted anymore when this happens.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Andi Kleen <[email protected]>
CC: Andi Kleen <[email protected]>
2006-09-26 10:52:39 +02:00
Arjan van de Ven 0a42540580 [PATCH] Add the canary field to the PDA area and the task struct
This patch adds the per thread cookie field to the task struct and the PDA.
Also it makes sure that the PDA value gets the new cookie value at context
switch, and that a new task gets a new cookie at task creation time.

Signed-off-by: Arjan van Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Andi Kleen <[email protected]>
CC: Andi Kleen <[email protected]>
2006-09-26 10:52:38 +02:00
Arjan van de Ven b62a5c740d [PATCH] Add the Kconfig option for the stackprotector feature
This patch adds the config options for -fstack-protector.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Andi Kleen <[email protected]>
CC: Andi Kleen <[email protected]>
2006-09-26 10:52:38 +02:00
Arjan van de Ven 29a9af60e2 [PATCH] Add comments to the PDA structure to annotate offsets
Change the comments in the pda structure to make the first fields to have
their offset documented and to have the comments aligned.
The stack protector series needs a field at offset 40 (gcc ABI); annotate
upto 40 for that reason.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Andi Kleen <[email protected]>
CC: Andi Kleen <[email protected]>
2006-09-26 10:52:38 +02:00
Arjan van de Ven e07e23e1fd [PATCH] non lazy "sleazy" fpu implementation
Right now the kernel on x86-64 has a 100% lazy fpu behavior: after *every*
context switch a trap is taken for the first FPU use to restore the FPU
context lazily.  This is of course great for applications that have very
sporadic or no FPU use (since then you avoid doing the expensive
save/restore all the time).  However for very frequent FPU users...  you
take an extra trap every context switch.

The patch below adds a simple heuristic to this code: After 5 consecutive
context switches of FPU use, the lazy behavior is disabled and the context
gets restored every context switch.  If the app indeed uses the FPU, the
trap is avoided.  (the chance of the 6th time slice using FPU after the
previous 5 having done so are quite high obviously).

After 256 switches, this is reset and lazy behavior is returned (until
there are 5 consecutive ones again).  The reason for this is to give apps
that do longer bursts of FPU use still the lazy behavior back after some
time.

[[email protected]: place new task_struct field next to jit_keyring to save space]
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andi Kleen <[email protected]>
Cc: Andi Kleen <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
2006-09-26 10:52:36 +02:00
Arjan van de Ven 76f10ad0e6 [NET]: Remove lockdep_set_class() call from skb_queue_head_init().
The skb_queue_head_init() function is used both in drivers for private use
and in the core networking code.  The usage models are vastly set of
functions that is only softirq safe; while the driver usage tends to be
more limited to a few hardirq safe accessor functions.  Rather than
annotating all 133+ driver usages, for now just split this lock into a per
queue class.  This change is obviously safe and probably should make
2.6.18.

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]>
2006-08-02 14:06:55 -07:00
Arjan van de Ven 5b6509aa8c [PATCH] inotify: fix deadlock found by lockdep
This is a real deadlock, a nice complex one:
(warning: long explanation follows so that Andrew can have a complete
patch description)

it's an ABCDA deadlock:

A iprune_mutex
B inode->inotify_mutex
C ih->mutex
D dev->ev_mutex

The AB relationship comes straight from invalidate_inodes()

int invalidate_inodes(struct super_block * sb)
{
        int busy;
        LIST_HEAD(throw_away);

        mutex_lock(&iprune_mutex);
        spin_lock(&inode_lock);
        inotify_unmount_inodes(&sb->s_inodes);

where inotify_umount_inodes() takes the
                mutex_lock(&inode->inotify_mutex);

The BC relationship comes directly from inotify_find_update_watch():
s32 inotify_find_update_watch(struct inotify_handle *ih, struct inode *inode,
                              u32 mask)
{
   ...
        mutex_lock(&inode->inotify_mutex);
        mutex_lock(&ih->mutex);

The CD relationship comes from inotify_rm_wd:
inotify_rm_wd does
        mutex_lock(&inode->inotify_mutex);
        mutex_lock(&ih->mutex)
and then calls inotify_remove_watch_locked() which calls
notify_dev_queue_event() which does
	        mutex_lock(&dev->ev_mutex);

(this strictly is a BCD relationship)

The DA relationship comes from the most interesting part:

  [<ffffffff8022d9f2>] shrink_icache_memory+0x42/0x270
  [<ffffffff80240dc4>] shrink_slab+0x11d/0x1c9
  [<ffffffff802b5104>] try_to_free_pages+0x187/0x244
  [<ffffffff8020efed>] __alloc_pages+0x1cd/0x2e0
  [<ffffffff8025e1f8>] cache_alloc_refill+0x3f8/0x821
  [<ffffffff8020a5e5>] kmem_cache_alloc+0x85/0xcb
  [<ffffffff802db027>] kernel_event+0x2e/0x122
  [<ffffffff8021d61c>] inotify_dev_queue_event+0xcc/0x140

inotify_dev_queue_event schedules a kernel_event which does a
kmem_cache_alloc( , GFP_KERNEL) which may try to shrink slabs, including
the inode cache .. which then takes iprune_mutex.

And voila, there is an AB, a BC, a CD relationship (even a direct BCD),
and also now a DA relationship -> a circular type AB-BA deadlock but
involving 4 locks.

The solution is simple: kernel_event() is NOT allowed to use GFP_KERNEL,
but must use GFP_NOFS to not cause recursion into the VFS.

Signed-off-by: Arjan van de Ven <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Acked-by: Robert Love <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-07-31 13:28:41 -07:00
Arjan van de Ven 8e185d8339 [PATCH] lockdep: annotate pktcdvd natural device hierarchy
The pkt_*_dev functions operate on not-this-blockdevice, and that is
sufficiently checked at setup time.  As a result there is a natural
hierarchy, which needs nesting annotations

Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Peter Osterlund <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-07-31 13:28:39 -07:00
Arjan van de Ven 153d7f3fca [PATCH] Reorganize the cpufreq cpu hotplug locking to not be totally bizare
The patch below moves the cpu hotplugging higher up in the cpufreq
layering; this is needed to avoid recursive taking of the cpu hotplug
lock and to otherwise detangle the mess.

The new rules are:
1. you must do lock_cpu_hotplug() around the following functions:
   __cpufreq_driver_target
   __cpufreq_governor (for CPUFREQ_GOV_LIMITS operation only)
   __cpufreq_set_policy
2. governer methods (.governer) must NOT take the lock_cpu_hotplug()
   lock in any way; they are called with the lock taken already
3. if your governer spawns a thread that does things, like calling
   __cpufreq_driver_target, your thread must honor rule #1.
4. the policy lock and other cpufreq internal locks nest within
   the lock_cpu_hotplug() lock.

I'm not entirely happy about how the __cpufreq_governor rule ended up
(conditional locking rule depending on the argument) but basically all
callers pass this as a constant so it's not too horrible.

The patch also removes the cpufreq_governor() function since during the
locking audit it turned out to be entirely unused (so no need to fix it)

The patch works on my testbox, but it could use more testing
(otoh... it can't be much worse than the current code)

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-07-26 07:21:40 -07:00
Arjan van de Ven ddca60c590 [PATCH] lockdep: annotate the BLKPG_DEL_PARTITION ioctl
The delete partition IOCTL takes the bd_mutex for both the disk and the
partition; these have an obvious hierarchical relationship and this patch
annotates this relationship for lockdep.

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]>
2006-07-14 21:53:53 -07:00
Arjan van de Ven 232ba9dbd6 [PATCH] lockdep: annotate the sysfs i_mutex to be a separate class
sysfs has a different i_mutex lock order behavior for i_mutex than the
other filesystems; sysfs i_mutex is called in many places with subsystem
locks held.  At the same time, many of the VFS locking rules do not apply
to sysfs at all (cross directory rename for example).  To untangle this
mess (which gives false positives in lockdep), we're giving sysfs inodes
their own class for i_mutex.

Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Greg KH <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-07-12 12:52:54 -07:00
Arjan van de Ven 2c16e9c888 [PATCH] lockdep: disable lock debugging when kernel state becomes untrusted
Disable lockdep debugging in two situations where the integrity of the
kernel no longer is guaranteed: when oopsing and when hitting a
tainting-condition.  The goal is to not get weird lockdep traces that don't
make sense or are otherwise undebuggable, to not waste time.

Lockdep assumes that the previous state it knows about is valid to operate,
which is why lockdep turns itself off after the first violation it reports,
after that point it can no longer make that assumption.

A kernel oops means that the integrity of the kernel compromised; in
addition anything lockdep would report is of lesser importance than the
oops.

All the tainting conditions are of similar integrity-violating nature and
also make debugging/diagnosing more difficult.

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]>
2006-07-10 13:24:27 -07:00
Arjan van de Ven 55794a412f [PATCH] lockdep: improve debug output
Make lockdep print which lock is held, in the "kfree() of a live lock"
scenario.

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]>
2006-07-10 13:24:14 -07:00
Arjan van de Ven 1252ecf63f [ATM]: fix possible recursive locking in skb_migrate()
ok this is a real potential deadlock in a way, it takes two locks of 2
skbuffs without doing any kind of lock ordering; I think the following
patch should fix it. Just sort the lock taking order by address of the
skb.. it's not pretty but it's the best this can do in a minimally
invasive way.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Chas Williams <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
2006-07-08 13:30:52 -07:00
Arjan van de Ven 5dd8d1e9eb [PATCH] lockdep: annotate vlan net device as being a special class
vlan network devices have devices nesting below it, and are a special
"super class" of normal network devices; split their locks off into a
separate class since they always nest.

[[email protected]: fix possible null-pointer deref]
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Frederik Deweerdt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-07-03 15:27:10 -07:00
Arjan van de Ven 933a2efc59 [PATCH] lockdep: annotate sound/core/seq/seq_device.c
The ops structure has complex locking rules, where not all ops are equal, some
are subordinate on others for some complex sound cards.  This requires for
lockdep checking that each individual reg_mutex is considered in separation
for its locking rules.

Has no effect on non-lockdep kernels.

Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Takashi Iwai <[email protected]>
Cc: Jaroslav Kysela <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-07-03 15:27:08 -07:00
Arjan van de Ven 8e7795ef6b [PATCH] lockdep: annotate USBFS
In usbfs's fs_remove_file() function, the aim is to remove a file or
directory from usbfs. This is done by first taking the i_mutex of the
parent directory of this file/dir via
  mutex_lock(&parent->d_inode->i_mutex);
and then to call either usbfs_rmdir() for a directory or usbfs_unlink()
for a file. Both these functions then take the i_mutex for the
to-be-removed object themselves:
  mutex_lock(&inode->i_mutex);

This is a classical parent->child locking order relationship that the VFS uses
all over the place; the VFS locking rule is "you need to take the parent
first".  This patch annotates the usbfs code to make this explicit and thus
informs the lockdep code that those two locks indeed have this relationship.

The rules for unlink that we already use in the VFS for unlink are to use
I_MUTEX_PARENT for the parent directory, and a normal mutex for the file
itself; this patch follows that convention.

Has no effect on non-lockdep kernels.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Greg KH <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-07-03 15:27:08 -07:00
Arjan van de Ven 5c81a4197d [PATCH] lockdep: annotate the quota code
The quota code plays interesting games with the lock ordering; to quote Jan:

| i_mutex of inode containing quota file is acquired after all other
| quota locks. i_mutex of all other inodes is acquired before quota
| locks. Quota code makes sure (by resetting inode operations and
| setting special flag on inode) that noone tries to enter quota code
| while holding i_mutex on a quota file...

The good news is that all of this special case i_mutex grabbing happens in the
(per filesystem) low level quota write function.  For this special case we
need a new I_MUTEX_* nesting level, since this just entirely outside any of
the regular VFS locking rules for i_mutex.  I trust Jan on his blue eyes that
this is not ever going to deadlock; and based on that the patch below is what
it takes to inform lockdep of these very interesting new locking rules.

The new locking rule for the I_MUTEX_QUOTA nesting level is that this is the
deepest possible level of nesting for i_mutex, and that this only should be
used in quota write (and possibly read) function of filesystems.  This makes
the lock ordering of the I_MUTEX_* levels:

I_MUTEX_PARENT -> I_MUTEX_CHILD -> I_MUTEX_NORMAL -> I_MUTEX_QUOTA

Has no effect on non-lockdep kernels.

Signed-off-by: Arjan van de Ven <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Cc: Jan Kara <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-07-03 15:27:08 -07:00
Arjan van de Ven 3aceafc1e2 [PATCH] lockdep: annotate serio
The PS/2 code has a natural device order and there is a one level recursion in
this device order in terms of the cmd_mutex; annotate this explicit recursion
as ok.

Has no effect on non-lockdep kernels.

Signed-off-by: Arjan van de Ven <[email protected]>
Cc: Dmitry Torokhov <[email protected]>
Cc: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-07-03 15:27:07 -07:00
Arjan van de Ven 4b7a89a3c1 [PATCH] pcmcia: fix deadlock in pcmcia_parse_events
The PCMCIA layer calls pcmcia_parse_events both from user context and
IRQ context; the lock thus needs to be irqsave to avoid deadlocks

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Dominik Brodowski <[email protected]>
2006-06-30 22:09:13 +02:00
Arjan van de Ven f71d20e961 [PATCH] Add EXPORT_UNUSED_SYMBOL and EXPORT_UNUSED_SYMBOL_GPL
Temporarily add EXPORT_UNUSED_SYMBOL and EXPORT_UNUSED_SYMBOL_GPL.  These
will be used as a transition measure for symbols that aren't used in the
kernel and are on the way out.  When a module uses such a symbol, a warning
is printk'd at modprobe time.

The main reason for removing unused exports is size: eacho export takes
roughly between 100 and 150 bytes of kernel space in the binary.  This
patch gives users the option to immediately get this size gain via a config
option.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-06-28 14:59:04 -07:00
Arjan van de Ven 9f125d3048 [PATCH] PCI: Add a "enable" sysfs attribute to the pci devices to allow userspace (Xorg) to enable devices without doing foul direct access
This patch adds an "enable" sysfs attribute to each PCI device. When read it
shows the "enabled-ness" of the device, but you can write a "0" into it to
disable a device, and a "1" to enable it.

This later is needed for X and other cases where userspace wants to enable
the BARs on a device (typical example: to run the video bios on a secundary
head). Right now X does all this "by hand" via bitbanging, that's just evil.
This allows X to no longer do that but to just let the kernel do this.

Signed-off-by: Arjan van de Ven <[email protected]>
CC: Peter Jones <[email protected]>
Acked-by: Dave Airlie <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
2006-06-21 11:59:59 -07:00
Arjan van de Ven 5d25ea7c0c [PATCH] unused exports in wireless drivers
There's a bunch of unused exports in the wireless drivers; that's
bad since unused exports take up quite a bit of space in total;
the patch below removes them.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: John W. Linville <[email protected]>
2006-05-17 14:58:55 -04:00
Arjan van de Ven 946f2ee5c7 [PATCH] i386/x86-64: Check that MCFG points to an e820 reserved area
This patch introduces a user for the e820_all_mapped function:

There have been several machines that don't have a working MMCONFIG,
often because of a buggy MCFG table in the ACPI bios.  This patch adds a
simple sanity check that detects a whole bunch of these cases, and when
it detects it, linux now boots rather than crash-and-burns.

The accuracy of this detection can in principle be improved if there was
a "is this entire range in e820 with THIS attribute", but no such
function exist and the complexity needed for this is not really worth
it; this simple check already catches most cases anyway.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andi Kleen <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-04-09 11:53:51 -07:00
Arjan van de Ven 952223683e [PATCH] x86_64: Introduce e820_all_mapped
Introduce a e820_all_mapped() function which checks if the entire range
<start,end> is mapped with type.

This is done by moving the local start variable to the end of each
known-good region; if at the end of the function the start address is
still before end, there must be a part that's not of the correct type;
otherwise it's a good region.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andi Kleen <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-04-09 11:53:50 -07:00
Arjan van de Ven eee5a9fa63 [PATCH] x86_64: Rename e820_mapped to e820_any_mapped
Rename e820_mapped to e820_any_mapped since it tests if any part of the
range is mapped according to the type.

Later steps will introduce e820_all_mapped which will check if the
entire range is mapped with the type.  Both have their merit.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andi Kleen <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-04-09 11:53:17 -07:00
Arjan van de Ven 597a7679dd [PATCH] revert incorrect mutex conversion in hdaps driver
This reverts the mutex conversion that was recently done to the hdaps
driver; this coversion was buggy because the hdaps driver started using
this semaphore in IRQ context, which mutexes do not allow.  Easiest
solution for now is to just revert the patch (the patch was part of a
bigger GIT commit, 9a61bf6300 but this
only reverts this one file)

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-04-02 13:02:05 -07:00
Arjan van de Ven df92004ce6 [PATCH] x86_64: Reorder one field of the PDA to reduce padding
This reorders the mmu_state int in the pda, such that there is no more
padding (there currently is 4 bytes of padding).  Boot tested.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andi Kleen <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-03-25 09:10:56 -08:00
Arjan van de Ven eaeae0cc98 [PATCH] x86_64: Patch to make the head.S-must-be-first-in-vmlinux order explicit
This patch puts the code from head.S in a special .bootstrap.text
section.

I'm working on a patch to reorder the functions in the kernel (I'll post
that later), but for x86-64 at least the kernel bootstrap requires that
the head.S functions are on the very first page/pages of the kernel
text.  This is understandable since the bootstrap is complex enough
already and not a problem at all, it just means they aren't allowed to
be reordered.  This patch puts these special functions into a separate
section to document this, and to guarantee this in the light of possibly
reordering the rest later.

(So this patch doesn't fix a bug per se, but makes things more robust by
making the order of these functions explicit)

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Andi Kleen <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-03-25 09:10:55 -08:00
Arjan van de Ven 4136cabff3 [PATCH] edac: disable a few sysfs files to avoid them becoming an ABI
Disable (via ugly #if 0's) the 3 sysfs files that I think by now we all
agree are very much wrong.  These files shouldn't become part of the ABI by
the 2.6.16 release, so I rather have this minimal patch merged to disable
them for now, the real fix can then come during the 2.6.17 devel window.

Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2006-03-11 09:19:34 -08:00