Currently a simple
void foo(void) { preempt_enable(); }
produces the following code on ARM:
foo:
bic r3, sp, #8128
bic r3, r3, #63
ldr r2, [r3, #4]
ldr r1, [r3, #0]
sub r2, r2, #1
tst r1, #4
str r2, [r3, #4]
blne preempt_schedule
mov pc, lr
The problem is that the TIF_NEED_RESCHED flag is loaded _before_ the
preemption count is stored back, hence any interrupt coming within that
3 instruction window causing TIF_NEED_RESCHED to be set won't be
seen and scheduling won't happen as it should.
Nothing currently prevents gcc from performing that reordering. There
is already a barrier() before the decrement of the preemption count, but
another one is needed between this and the TIF_NEED_RESCHED flag test
for proper code ordering.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Acked-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Jan's crosscompile page [1] shows, that one regression in 2.6.15-rc is
that the v850 defconfig does no longer compile.
The compile error is:
<-- snip -->
...
CC arch/v850/kernel/setup.o
In file included from /usr/src/ctest/rc/kernel/arch/v850/kernel/setup.c:17:
/usr/src/ctest/rc/kernel/include/linux/irq.h:13:43: asm/smp.h: No such file or directory
make[2]: *** [arch/v850/kernel/setup.o] Error 1
<-- snip -->
The #include <asm/smp.h> in irq.h was intruduced in 2.6.15-rc.
Since include/linux/irq.h needs code from asm/smp.h only in the
CONFIG_SMP=y case and linux/smp.h #include's asm/smp.h only in the
CONFIG_SMP=y case, I'm suggesting this patch to #include <linux/smp.h>
in irq.h.
I've tested the compilation with both CONFIG_SMP=y and CONFIG_SMP=n
on i386.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There's currently a diagnostic printk in relay_switch_subbuf() meant as
a warning if you accidentally try to log an event larger than the
sub-buffer size.
The problem is if this happens while logging from somewhere it's not
safe to be doing printks, such as in the scheduler, you can end up with
a deadlock. This patch removes the warning from relay_switch_subbuf()
and instead prints some diagnostic info when the channel is closed.
Thanks to Mathieu Desnoyers for pointing out the problem and
suggesting a fix.
Signed-off-by: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Ensure we call unmap_mapping_range() and sync dirty pages to disk before
doing an NFS direct write.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
I reported a problem and gave hints to the solution, but nobody seemed
to react. So I prepared a patch against 2.6.14.4.
Tested on 2.6.14.4 with "ip monitor addr" and with the program
attached, while adding and removing IPv6 address. Both programs didn't
receive any messages. Tested 2.6.14.4 + this patch, and both programs
received add and remove messages.
Signed-off-by: Kristian Slavov <kristian.slavov@nomadiclab.com>
Acked-by: Jamal Hadi salim <hadi@cyberus.ca>
ACKed-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This (and the three subsequent patches) is working well on OMAP H4 with
2.6.15-rc4 kernel and passes the LTP fs test.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
sparc64, i386 and x86_64 have support for a special data section dedicated
to rarely updated data that is frequently read. The section was created to
avoid false sharing of those rarely read data with frequently written kernel
data.
This patch creates such a data section for ia64 and will group rarely written
data into this section.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
The logic that decides that a fork() might be able to avoid copying a VM
area when it can be re-created by page faults didn't know about the new
vm_insert_page() case.
Also make some things a bit more anal wrt VM_PFNMAP.
Pointed out by Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This merge is pretty extensive. The conflict is over the new
req->retries parameter, so I had to change the prototype to
scsi_setup_blk_pc_cmnd() and the usage in sd, sr and st.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
- export __blk_put_request and blk_execute_rq_nowait
needed for async REQ_BLOCK_PC requests
- seperate max_hw_sectors and max_sectors for block/scsi_ioctl.c and
SG_IO bio.c helpers per Jens's last comments. Since block/scsi_ioctl.c SG_IO was
already testing against max_sectors and SCSI-ml was setting max_sectors and
max_hw_sectors to the same value this does not change any scsi SG_IO behavior. It only
prepares ll_rw_blk.c, scsi_ioctl.c and bio.c for when SCSI-ml begins to set
a valid max_hw_sectors for all LLDs. Today if a LLD does not set it
SCSI-ml sets it to a safe default and some LLDs set it to a artificial low
value to overcome memory and feedback issues.
Note: Since we now cap max_sectors to BLK_DEF_MAX_SECTORS, which is 1024,
drivers that used to call blk_queue_max_sectors with a large value of
max_sectors will now see the fs requests capped to BLK_DEF_MAX_SECTORS.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
http://bugzilla.kernel.org/show_bug.cgi?id=4320
Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Len Brown <len.brown@intel.com>
For tape we need to control the retries. This patch adds a retries
counter on the request for REQ_BLOCK_PC commands originating from
scsi_execute* to use. REQ_BLOCK_PC commands comming from the block
layer SG_IO path continue to use the retires set in the ULD init_command.
(scsi_execute* does not set the gendisk so we do not execute
the init_command in that path).
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Add scsi helpers to create really-large-requests and convert
scsi-ml to scsi_execute_async().
Per Jens's previous comments, I placed this function in scsi_lib.c.
I made it follow all the queue's limits - I think I did at least :), so
I removed the warning on the function header.
I think the scsi_execute_* functions should eventually take a request_queue
and be placed some place where the dm-multipath hw_handler can use them
if that failover code is going to stay in the kernel. That conversion
patch will be sent in another mail though.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
To send async requests we need these two functions exported.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Some motherboards (such as the Asus P5V800-MX) ship a
PCI_DEVICE_ID_VIA_82C586_1 IDE controller alongside a VT8251 southbridge.
This southbridge is currently unrecognised in the via82cxxx IDE driver,
preventing those users from getting DMA access to disks.
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Some hardware does not support the PACKET command at all.
Other hardware supports ATAPI, but the driver does something nasty such
as calling BUG() when an ATAPI command is issued.
For these such cases, we mark them with a new flag, ATA_FLAG_NO_ATAPI.
Initial version contributed by Ben Collins.
There is no user of qc->waiting left after ata_exec_internal()
changes. Kill the field.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
This patch implements ata_exec_internal() function which performs
libata internal command execution. Previously, this was done by each
user by manually initializing a qc, issueing it, waiting for its
completion and handling errors. In addition to obvious code
factoring, using ata_exec_internal() fixes the following bugs.
* qc not freed on issue failure
* ap->qactive clearing could race with the next internal command
* race between timeout handling and irq
* ignoring error condition not represented in tf->status
Also, qc & hardware are not accessed anymore once it's completed,
making internal commands more conformant with general semantics.
ata_exec_internal() also makes it easy to issue internal commands from
multiple threads if that becomes necessary.
This patch only implements ata_exec_internal(). A following patch
will convert all users.
Signed-off-by: Tejun Heo <htejun@gmail.com>
--
Jeff, all patches have been regenerated against upstream branch as of
today. (575ab52a21)
Also, I took out a debug printk from ata_exec_internal (don't know how
that one got left there). Other than that, all patches are identical
to the previous posting.
Thanks. :-)
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
The drawing function cfbfillrect does not work correctly when access is not
unsigned-long aligned. It manifests as extra lines of pixels that are not
complete drawn. Reversing the shift operator solves the problem, so I would
presume that this bug would manifest only on little endian machines. The
function cfbcopyarea may also have this bug.
Aligned access should present no problems.
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Every framebuffer driver relies on the assumption that the set_par()
function of the driver is called before drawing functions and other
functions dependent on the hardware state are executed.
Whenever you switch from X to a framebuffer console for the very first
time, there is a chance that a broken X system has _not_ set the mode to
KD_GRAPHICS, thus the vt and framebuffer code executes a screen redraw and
several other functions before a set_par() is executed. This is believed
to be not a bug of linux but a bug of X/xdm. At least some X releases used
by SuSE and Debian show this behaviour.
There was a 2nd case, but that has been fixed by Antonino Daplas on
10-dec-2005.
This patch allows drivers to set a flag to inform fbcon_switch() that they
prefer a set_par() call on every console switch, working around the
problems caused by the broken X releases.
The flag will be used by the next release of cyblafb and might help other
drivers that assume a hardware state different to the one used by X.
As the default behaviour does not change, this patch should be acceptable
to everybody.
Signed-off-by: Knut Petersen <Knut_Petersen@t-online.de>
Acked-by: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add hooks to save and restore the graphics state. These hooks are called in
fbcon_blank() when entering/leaving KD_GRAPHICS mode. This is needed by
savagefb at least so it can cooperate with savage_dri and by cyblafb.
State save/restoration can be full or partial.
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Spotted by a Fedora user. Compiling with DEBUG_PARPORT set fails due to
the broken cast.
Just remove it.
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When multiple probes are registered at the same address and if due to some
recursion (probe getting triggered within a probe handler), we skip calling
pre_handlers and just increment nmissed field.
The below patch make sure it walks the list for multiple probes case.
Without the below patch we get incorrect results of nmissed count for
multiple probe case.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
For Kprobes critical path is the path from debug break exception handler
till the control reaches kprobes exception code. No probes can be
supported in this path as we will end up in recursion.
This patch prevents this by moving the below function to safe __kprobes
section onto which no probes can be inserted.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The below patch lets userspace have more control over the inodes that
inotify will watch. It introduces two new flags.
IN_ONLYDIR -- only watch the inode if it is a directory.
This is needed to avoid the race that can occur when we want to be
sure that we are watching a directory.
IN_DONT_FOLLOW -- don't follow a symlink. In combination
with IN_ONLYDIR we can make sure that we don't watch the target of
symlinks.
The issues the flags fix came up when writing the gnome-vfs inotify
backend. Default behaviour is unchanged.
Signed-off-by: John McCutchan <ttb@tentacle.dhs.org>
Acked-by: Robert Love <rml@novell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add list_replace_rcu: replace old entry by new one.
Signed-off-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds a timestamp field to the events sent via the process event
connector. The timestamp allows listeners to accurately account the
duration(s) between a process' events and offers strong means with which
to determine the order of events with respect to a given task while also
avoiding the addition of per-task data.
This alters the size and layout of the event structure and hence would
break compatibility if process events connector as it stands in 2.6.15-rc2
were released as a mainline kernel.
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There are several functions that might seem appropriate for a timestamp:
get_cycles()
current_kernel_time()
do_gettimeofday()
<read jiffies/jiffies_64>
Each has problems with combinations of SMP-safety, low resolution, and
monotonicity. This patch adds a new function that returns a monotonic SMP-safe
timestamp with nanosecond resolution where available.
Changes:
Split timestamp into separate patch
Moved to kernel/time.c
Renamed to getnstimestamp
Fixed unintended-pointer-arithmetic bug
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This introduces a new interface - rcu_barrier() which waits until all
the RCUs queued until this call have been completed.
Reiser4 needs this, because we do more than just freeing memory object
in our RCU callback: we also remove it from the list hanging off
super-block. This means, that before freeing reiser4-specific portion
of super-block (during umount) we have to wait until all pending RCU
callbacks are executed.
The only change of reiser4 made to the original patch, is exporting of
rcu_barrier().
Cc: Hans Reiser <reiser@namesys.com>
Cc: Vladimir V. Saveliev <vs@namesys.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With the previous commit, we can handle arbitrary shared re-mappings
even without this complexity, and since the only known private mappings
are for strange users of /dev/mem (which never create an incomplete one),
there seems to be no reason to support it.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
