Impact: fix rare runtime deadlock
There are a few sites that do:
spin_lock_irq(&foo)
hrtimer_start(&bar)
__run_hrtimer(&bar)
func()
spin_lock(&foo)
which obviously deadlocks. In order to avoid this, never call __run_hrtimer()
from hrtimer_start*() context, but instead defer this to softirq context.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
No need for a smp function call, which is likely to run on the same
CPU anyway. We can just call hrtimers_peek_ahead() in the interrupts
disabled section of migrate_hrtimers().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
kernel/hrtimer.c: In function 'hrtimer_cpu_notify':
kernel/hrtimer.c:1574: warning: unused variable 'dcpu'
Introduced by commit 37810659ea
("hrtimer: removing all ur callback modes, fix hotplug") from the
timers. dcpu is only used if CONFIG_HOTPLUG_CPU is set.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
Provide a peek ahead function that assumes irqs disabled, allows for micro
optimizations.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix an rcutorture bug that prevents the shutdown notifier from ever
actually having any effect, due to the fact that kthreads ignore all
signals.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The various fields in NDTR{01} are in units of clock ticks minus one, but the
ns2cycle macro mistakenly adds one, inflating the number of clock ticks and
making it impossible to set any of these fields to zero.
Signed-off-by: Matt Reimer <mreimer@vpop.net>
Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Reads from non-page-aligned addresses were broken because while the
address to read from was correctly written to NDCB*, a full page was
always read. Fix this by ignoring the column and only using the page
address.
I suspect this whole-page behavior is due to the controller's need to
read the entire page in order to generate correct ECC. In the non-ECC
case this could be optimized to use the column address, and to set the
read length to what is being requested rather than the length of an
entire page.
Signed-off-by: Matt Reimer <mreimer@vpop.net>
Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Fix sched.h references:
build-r7149.out:/local/linsrc/linux-next-20081215/drivers/mtd/nand/nandsim.c:1326: error: dereferencing pointer to incomplete type
build-r7149.out:/local/linsrc/linux-next-20081215/drivers/mtd/nand/nandsim.c:1326: error: 'PF_MEMALLOC' undeclared (first use in this function)
build-r7149.out:/local/linsrc/linux-next-20081215/drivers/mtd/nand/nandsim.c:1328: error: dereferencing pointer to incomplete type
build-r7149.out:/local/linsrc/linux-next-20081215/drivers/mtd/nand/nandsim.c:1335: error: dereferencing pointer to incomplete type
build-r7149.out:/local/linsrc/linux-next-20081215/drivers/mtd/nand/nandsim.c:1335: error: 'PF_MEMALLOC' undeclared (first use in this function)
build-r7149.out:make[4]: *** [drivers/mtd/nand/nandsim.o] Error 1
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This set of patches introduces calls to the following set of functions:
usb_endpoint_dir_in(epd)
usb_endpoint_dir_out(epd)
usb_endpoint_is_bulk_in(epd)
usb_endpoint_is_bulk_out(epd)
usb_endpoint_is_int_in(epd)
usb_endpoint_is_int_out(epd)
usb_endpoint_num(epd)
usb_endpoint_type(epd)
usb_endpoint_xfer_bulk(epd)
usb_endpoint_xfer_control(epd)
usb_endpoint_xfer_int(epd)
usb_endpoint_xfer_isoc(epd)
In some cases, introducing one of these functions is not possible, and it
just replaces an explicit integer value by one of the following constants:
USB_ENDPOINT_XFER_BULK
USB_ENDPOINT_XFER_CONTROL
USB_ENDPOINT_XFER_INT
USB_ENDPOINT_XFER_ISOC
An extract of the semantic patch that makes these changes is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@r1@ struct usb_endpoint_descriptor *epd; @@
- ((epd->bmAttributes & \(USB_ENDPOINT_XFERTYPE_MASK\|3\)) ==
- \(USB_ENDPOINT_XFER_CONTROL\|0\))
+ usb_endpoint_xfer_control(epd)
@r5@ struct usb_endpoint_descriptor *epd; @@
- ((epd->bEndpointAddress & \(USB_ENDPOINT_DIR_MASK\|0x80\)) ==
- \(USB_DIR_IN\|0x80\))
+ usb_endpoint_dir_in(epd)
@inc@
@@
#include <linux/usb.h>
@depends on !inc && (r1||r5)@
@@
+ #include <linux/usb.h>
#include <linux/usb/...>
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
at32_reserve_pin now takes an u32 bitmask rather than a single pin.
This allows to reserve multiple pins at once.
Remove (undocumented) SDCS (pin PE26) from reservation in board
setup code.
Signed-off-by: Alex Raimondi <raimondi@miromico.ch>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
This patch removes a call to the deprecated function
at32_add_system_devices().
Signed-off-by: Mark Jackson <mpfj@mimc.co.uk>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
(I did not compile or test it, please let me know, or help fixing
it, if something is wrong with the conversion)
This patch is part of a larger patch series which will remove
the "char bus_id[20]" name string from struct device. The device
name is managed in the kobject anyway, and without any size
limitation, and just needlessly copied into "struct device".
To set and read the device name dev_name(dev) and dev_set_name(dev)
must be used. If your code uses static kobjects, which it shouldn't
do, "const char *init_name" can be used to statically provide the
name the registered device should have. At registration time, the
init_name field is cleared, to enforce the use of dev_name(dev) to
access the device name at a later time.
We need to get rid of all occurrences of bus_id in the entire tree
to be able to enable the new interface. Please apply this patch,
and possibly convert any remaining remaining occurrences of bus_id.
We want to submit a patch to -next, which will remove bus_id from
"struct device", to find the remaining pieces to convert, and finally
switch over to the new api, which will remove the 20 bytes array
and does no longer have a size limitation.
Thanks,
Kay
From: Kay Sievers <kay.sievers@vrfy.org>
Subject: avr: struct device - replace bus_id with dev_name(), dev_set_name()
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
fs/proc/base.c:312:4: warning: do-while statement is not a compound statement
Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
/proc/*/stack adds the ability to query a task's stack trace. It is more
useful than /proc/*/wchan as it provides full stack trace instead of single
depth. Example output:
$ cat /proc/self/stack
[<c010a271>] save_stack_trace_tsk+0x17/0x35
[<c01827b4>] proc_pid_stack+0x4a/0x76
[<c018312d>] proc_single_show+0x4a/0x5e
[<c016bdec>] seq_read+0xf3/0x29f
[<c015a004>] vfs_read+0x6d/0x91
[<c015a0c1>] sys_read+0x3b/0x60
[<c0102eda>] syscall_call+0x7/0xb
[<ffffffff>] 0xffffffff
[add save_stack_trace_tsk() on mips, ACK Ralf --adobriyan]
Signed-off-by: Ken Chen <kenchen@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
There are four BKL users in proc: de_put(), proc_lookup_de(),
proc_readdir_de(), proc_root_readdir(),
1) de_put()
-----------
de_put() is classic atomic_dec_and_test() refcount wrapper -- no BKL
needed. BKL doesn't matter to possible refcount leak as well.
2) proc_lookup_de()
-------------------
Walking PDE list is protected by proc_subdir_lock(), proc_get_inode() is
potentially blocking, all callers of proc_lookup_de() eventually end up
from ->lookup hooks which is protected by directory's ->i_mutex -- BKL
doesn't protect anything.
3) proc_readdir_de()
--------------------
"." and ".." part doesn't need BKL, walking PDE list is under
proc_subdir_lock, calling filldir callback is potentially blocking
because it writes to luserspace. All proc_readdir_de() callers
eventually come from ->readdir hook which is under directory's
->i_mutex -- BKL doesn't protect anything.
4) proc_root_readdir_de()
-------------------------
proc_root_readdir_de is ->readdir hook, see (3).
Since readdir hooks doesn't use BKL anymore, switch to
generic_file_llseek, since it also takes directory's i_mutex.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Impact: cleanup
Expand macro into two files.
The synchronize_rcu_xxx macro is quite ugly and it's only used by two
callers, so expand it instead. This makes this code easier to change.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix kernel warnings [and potential crash] during suspend+resume
Kudos to both Dhaval Giani and Jens Axboe for finding a bug in treercu
that causes warnings after suspend-resume cycles in Dhaval's case and
during stress tests in Jens's case. It would also probably cause failures
if heavily stressed. The solution, ironically enough, is to revert to
rcupreempt's code for initializing the dynticks state. And the patch
even results in smaller code -- so what was I thinking???
This is 2.6.29 material, given that people really do suspend and resume
Linux these days. ;-)
Reported-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Reported-by: Jens Axboe <jens.axboe@oracle.com>
Tested-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Tested-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix delays during bootup
Kudos to Andi Kleen for finding a grace-period-latency problem! The
problem was that the special-case code for small machines never updated
the ->signaled field to indicate that grace-period initialization had
completed, which prevented force_quiescent_state() from ever expediting
grace periods. This problem resulted in grace periods extending for more
than 20 seconds. Not subtle. I introduced this bug during my inspection
process when I fixed a race between grace-period initialization and
force_quiescent_state() execution.
The following patch properly updates the ->signaled field for the
"small"-system case (no more than 32 CPUs for 32-bit kernels and no more
than 64 CPUs for 64-bit kernels).
Reported-by: Andi Kleen <andi@firstfloor.org>
Tested-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In splice TCP receive, the SPLICE_F_NONBLOCK flag is used
to compute the "timeo" value. So checking it again inside
of the main receive loop to trigger -EAGAIN processing is
entirely unnecessary.
Noticed by Jarek P. and Lennert Buytenhek.
Signed-off-by: David S. Miller <davem@davemloft.net>
I started playing with pahole today and decided to put it against the
selinux structures. Found we could save a little bit of space on x86_64
(and no harm on i686) just reorganizing some structs.
Object size changes:
av_inherit: 24 -> 16
selinux_class_perm: 48 -> 40
context: 80 -> 72
Admittedly there aren't many of av_inherit or selinux_class_perm's in
the kernel (33 and 1 respectively) But the change to the size of struct
context reverberate out a bit. I can get some hard number if they are
needed, but I don't see why they would be. We do change which cacheline
context->len and context->str would be on, but I don't see that as a
problem since we are clearly going to have to load both if the context
is to be of any value. I've run with the patch and don't seem to be
having any problems.
An example of what's going on using struct av_inherit would be:
form: to:
struct av_inherit { struct av_inherit {
u16 tclass; const char **common_pts;
const char **common_pts; u32 common_base;
u32 common_base; u16 tclass;
};
(notice all I did was move u16 tclass to the end of the struct instead
of the beginning)
Memory layout before the change:
struct av_inherit {
u16 tclass; /* 2 */
/* 6 bytes hole */
const char** common_pts; /* 8 */
u32 common_base; /* 4 */
/* 4 byes padding */
/* size: 24, cachelines: 1 */
/* sum members: 14, holes: 1, sum holes: 6 */
/* padding: 4 */
};
Memory layout after the change:
struct av_inherit {
const char ** common_pts; /* 8 */
u32 common_base; /* 4 */
u16 tclass; /* 2 */
/* 2 bytes padding */
/* size: 16, cachelines: 1 */
/* sum members: 14, holes: 0, sum holes: 0 */
/* padding: 2 */
};
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
prom_nextprop() and prom_firstprop() have slightly different calling
conventions in 32 and 64 bit SPARC.
prom_common.c uses a ifdef guard to ensure that these functions are
called correctly.
Adjust code to eliminate this ifdef by using a calling convention that
is compatible with both 32 and 64 bit SPARC.
Signed-off-by: Julian Calaby <julian.calaby@gmail.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, setting SPLICE_F_NONBLOCK on splice from a TCP socket
results in masking of EOF (RDHUP) and error conditions on the socket
by an -EAGAIN return. Move the NONBLOCK check in tcp_splice_read()
to be after the EOF and error checks to fix this.
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
SPIN_LOCK_UNLOCKED is deprecated. The following makes the change suggested
in Documentation/spinlocks.txt
The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@@
declarer name DEFINE_SPINLOCK;
identifier xxx_lock;
@@
- spinlock_t xxx_lock = SPIN_LOCK_UNLOCKED;
+ DEFINE_SPINLOCK(xxx_lock);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
