Since 2.6.18-something, the community has been bugged by the problem to
provide a clean and a stable mechanism to postpone a cpu-hotplug event as
lock_cpu_hotplug was badly broken.
This is another proposal towards solving that problem. This one is along the
lines of the solution provided in kernel/workqueue.c
Instead of having a global mechanism like lock_cpu_hotplug, we allow the
subsytems to define their own per-subsystem hot cpu mutexes. These would be
taken(released) where ever we are currently calling
lock_cpu_hotplug(unlock_cpu_hotplug).
Also, in the per-subsystem hotcpu callback function,we take this mutex before
we handle any pre-cpu-hotplug events and release it once we finish handling
the post-cpu-hotplug events. A standard means for doing this has been
provided in [PATCH 2/4] and demonstrated in [PATCH 3/4].
The ordering of these per-subsystem mutexes might still prove to be a
problem, but hopefully lockdep should help us get out of that muddle.
The patch set to be applied against linux-2.6.19-rc5 is as follows:
[PATCH 1/4] : Extend notifier_call_chain with an option to specify the
number of notifications to be sent and also count the
number of notifications actually sent.
[PATCH 2/4] : Define events CPU_LOCK_ACQUIRE and CPU_LOCK_RELEASE
and send out notifications for these in _cpu_up and
_cpu_down. This would help us standardise the acquire and
release of the subsystem locks in the hotcpu
callback functions of these subsystems.
[PATCH 3/4] : Eliminate lock_cpu_hotplug from kernel/sched.c.
[PATCH 4/4] : In workqueue_cpu_callback function, acquire(release) the
workqueue_mutex while handling
CPU_LOCK_ACQUIRE(CPU_LOCK_RELEASE).
If the per-subsystem-locking approach survives the test of time, we can expect
a slow phasing out of lock_cpu_hotplug, which has not yet been eliminated in
these patches :)
This patch:
Provide notifier_call_chain with an option to call only a specified number of
notifiers and also record the number of call to notifiers made.
The need for this enhancement was identified in the post entitled
"Slab - Eliminate lock_cpu_hotplug from slab"
(http://lkml.org/lkml/2006/10/28/92) by Ravikiran G Thirumalai and
Andrew Morton.
This patch adds two additional parameters to notifier_call_chain API namely
- int nr_to_calls : Number of notifier_functions to be called.
The don't care value is -1.
- unsigned int *nr_calls : Records the total number of notifier_funtions
called by notifier_call_chain. The don't care
value is NULL.
[michal.k.k.piotrowski@gmail.com: build fix]
Credit: Andrew Morton <akpm@osdl.org> Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Wed, 9 May 2007 09:33:52 +0000 (02:33 -0700)]
implement flush_work()
A basic problem with flush_scheduled_work() is that it blocks behind _all_
presently-queued works, rather than just the work whcih the caller wants to
flush. If the caller holds some lock, and if one of the queued work happens
to want that lock as well then accidental deadlocks can occur.
One example of this is the phy layer: it wants to flush work while holding
rtnl_lock(). But if a linkwatch event happens to be queued, the phy code will
deadlock because the linkwatch callback function takes rtnl_lock.
So we implement a new function which will flush a *single* work - just the one
which the caller wants to free up. Thus we avoid the accidental deadlocks
which can arise from unrelated subsystems' callbacks taking shared locks.
flush_work() non-blockingly dequeues the work_struct which we want to kill,
then it waits for its handler to complete on all CPUs.
Add ->current_work to the "struct cpu_workqueue_struct", it points to
currently running "struct work_struct". When flush_work(work) detects
->current_work == work, it inserts a barrier at the _head_ of ->worklist
(and thus right _after_ that work) and waits for completition. This means
that the next work fired on that CPU will be this barrier, or another
barrier queued by concurrent flush_work(), so the caller of flush_work()
will be woken before any "regular" work has a chance to run.
When wait_on_work() unlocks workqueue_mutex (or whatever we choose to protect
against CPU hotplug), CPU may go away. But in that case take_over_work() will
move a barrier we queued to another CPU, it will be fired sometime, and
wait_on_work() will be woken.
Actually, we are doing cleanup_workqueue_thread()->kthread_stop() before
take_over_work(), so cwq->thread should complete its ->worklist (and thus
the barrier), because currently we don't check kthread_should_stop() in
run_workqueue(). But even if we did, everything should be ok.
Oleg Nesterov [Wed, 9 May 2007 09:33:51 +0000 (02:33 -0700)]
reimplement flush_workqueue()
Remove ->remove_sequence, ->insert_sequence, and ->work_done from struct
cpu_workqueue_struct. To implement flush_workqueue() we can queue a
barrier work on each CPU and wait for its completition.
The barrier is queued under workqueue_mutex to ensure that per cpu
wq->cpu_wq is alive, we drop this mutex before going to sleep. If CPU goes
down while we are waiting for completition, take_over_work() will move the
barrier on another CPU, and the handler will wake up us eventually.
Now that the cpu_is_xxx() macros are available both on AVR32 and AT91, we can
remove a couple of #ifdefs from this driver. One of them is actually wrong --
new_1 should be set on AVR32 but isn't. This causes the bus clock to run at
twice the speed it is configured to.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: David Brownell <david-b@pacbell.net> Acked-by: Andrew Victor <andrew@sanpeople.com> Cc: Nicolas Ferre <nicolas.ferre@rfo.atmel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Several drivers shared between AT91 and AVR32 chips use cpu_is_xxx()
to handle CPU-specific differences. Currently, such code needs to be
inside #ifdef CONFIG_ARCH_AT91 because the macros don't exist on AVR32.
By defining the same macros on both AT91 and AVR32, these #ifdefs can
be eliminated. Since the macros will evaluate to a constant value for
CPUs that aren't supported by the current architecture, any code that
is only needed on AT91 will be optimized away on AVR32 and vice versa.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: David Brownell <david-b@pacbell.net> Acked-by: Andrew Victor <andrew@sanpeople.com> Cc: Nicolas Ferre <nicolas.ferre@rfo.atmel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Howells [Wed, 9 May 2007 09:33:46 +0000 (02:33 -0700)]
AFS: implement basic file write support
Implement support for writing to regular AFS files, including:
(1) write
(2) truncate
(3) fsync, fdatasync
(4) chmod, chown, chgrp, utime.
AFS writeback attempts to batch writes into as chunks as large as it can manage
up to the point that it writes back 65535 pages in one chunk or it meets a
locked page.
Furthermore, if a page has been written to using a particular key, then should
another write to that page use some other key, the first write will be flushed
before the second is allowed to take place. If the first write fails due to a
security error, then the page will be scrapped and reread before the second
write takes place.
If a page is dirty and the callback on it is broken by the server, then the
dirty data is not discarded (same behaviour as NFS).
Shared-writable mappings are not supported by this patch.
[akpm@linux-foundation.org: fix a bunch of warnings] Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Miller [Wed, 9 May 2007 09:33:43 +0000 (02:33 -0700)]
Fix printk format warnings in timer_list.c
u64 and s64 are not necessarily 'long long' on some 64-bit
platforms, so explicit the type to kill the compiler warnings.
Also consistently use '%Lu' which is unsigned.
Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Randy Dunlap [Wed, 9 May 2007 09:33:42 +0000 (02:33 -0700)]
doc: what a patch series is
It seems that we need to clarify that a patch series is a series of related
patches rather than "here are some of my patches as multiple (numbered)
emails."
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Paul Fulghum [Wed, 9 May 2007 09:33:38 +0000 (02:33 -0700)]
tty_set_ldisc() receive_room fix
Fix tty_set_ldisc in tty_io.c so that tty->receive_room is only cleared if
actually changing line disciplines.
Without this fix a problem occurs when requesting the line discipline to
change to the same line discipline. In this case tty->receive_room is
cleared but ldisc->open() is not called to set tty->receive_room back to a
sane value. The result is that tty->receive_room is stuck at 0 preventing
the tty flip buffer from passing receive data to the line discipline.
For example: a switch from N_TTY to N_TTY followed by a select() call for
read input results in data never being received because tty->receive_room
is stuck at zero.
A switch from N_TTY to N_TTY followed by a read() call works because the
read() call itself sets tty->receive_room correctly (but select does not).
Previously (< 2.6.18) this was not a problem because the tty flip buffer
pushed data to the line discipline without regard for tty->receive room.
Signed-off-by: Paul Fulghum <paulkf@microgate.com> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Roland McGrath [Wed, 9 May 2007 09:33:37 +0000 (02:33 -0700)]
Move sig_kernel_* et al macros to linux/signal.h
This patch moves the sig_kernel_* and related macros from kernel/signal.c
to linux/signal.h, and cleans them up slightly. I need the sig_kernel_*
macros for default signal behavior in the utrace code, and want to avoid
duplication or overhead to share the knowledge.
Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ken Chen [Wed, 9 May 2007 09:33:34 +0000 (02:33 -0700)]
pretend cpuset has some form of hugetlb page reservation
When cpuset is configured, it breaks the strict hugetlb page reservation as
the accounting is done on a global variable. Such reservation is
completely rubbish in the presence of cpuset because the reservation is not
checked against page availability for the current cpuset. Application can
still potentially OOM'ed by kernel with lack of free htlb page in cpuset
that the task is in. Attempt to enforce strict accounting with cpuset is
almost impossible (or too ugly) because cpuset is too fluid that task or
memory node can be dynamically moved between cpusets.
The change of semantics for shared hugetlb mapping with cpuset is
undesirable. However, in order to preserve some of the semantics, we fall
back to check against current free page availability as a best attempt and
hopefully to minimize the impact of changing semantics that cpuset has on
hugetlb.
Signed-off-by: Ken Chen <kenchen@google.com> Cc: Paul Jackson <pj@sgi.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Akinobu Mita [Wed, 9 May 2007 09:33:33 +0000 (02:33 -0700)]
use simple_read_from_buffer in kernel/
Cleanup using simple_read_from_buffer() for /dev/cpuset/tasks and
/proc/config.gz.
Cc: Paul Jackson <pj@sgi.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
James Bottomley [Wed, 9 May 2007 09:33:30 +0000 (02:33 -0700)]
mca: add integrated device bus matching
The MCA bus has a few "integrated" functions, which are effectively virtual
slots on the bus. The problem is that these special functions don't have
dedicated pos IDs, so we have to manufacture ids for them outside the pos
space ... and these ids can't be matched by the standard matching function,
so add a special registration that requests a list of pos ids or a particular
integrated function.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
James Bottomley [Wed, 9 May 2007 09:33:29 +0000 (02:33 -0700)]
mca: fix bus matching
There's a bug in the MCA bus matching algorithm in that it promotes from
signed short to int before comparing with the actual id and does sign
extension on anything > 0x7fff (which means that pos ids > 0x7fff never get
correctly matched).
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the APIC to determine the hardware processor id - x86_64
hard_smp_processor_id used to be just a macro that hard-coded
hard_smp_processor_id to 0 in the non SMP case. When booting non SMP kernels
on hardware where the boot ioapic id is not 0 this turns out to be a problem.
This is happens frequently in the case of kdump and once in a great while in
the case of real hardware.
Use the APIC to determine the hardware processor id in both UP and SMP kernels
to fix this issue.
Notice that hard_smp_processor_id is only used by SMP code or by code that
works with apics so we do not need to handle the case when apics are not
present and hard_smp_processor_id should never be called there.
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Cc: "Luck, Tony" <tony.luck@intel.com> Acked-by: Andi Kleen <ak@suse.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the APIC to determine the hardware processor id - i386
hard_smp_processor_id used to be just a macro that hard-coded
hard_smp_processor_id to 0 in the non SMP case. When booting non SMP kernels
on hardware where the boot ioapic id is not 0 this turns out to be a problem.
This is happens frequently in the case of kdump and once in a great while in
the case of real hardware.
Use the APIC to determine the hardware processor id in both UP and SMP kernels
to fix this issue.
Notice that hard_smp_processor_id is only used by SMP code or by code that
works with apics so we do not need to handle the case when apics are not
present and hard_smp_processor_id should never be called there.
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Cc: "Luck, Tony" <tony.luck@intel.com> Acked-by: Andi Kleen <ak@suse.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove hardcoding of hard_smp_processor_id on UP systems
With the advent of kdump, the assumption that the boot CPU when booting an UP
kernel is always the CPU with a particular hardware ID (often 0) (usually
referred to as BSP on some architectures) is not valid anymore. The reason
being that the dump capture kernel boots on the crashed CPU (the CPU that
invoked crash_kexec), which may be or may not be that particular CPU.
Move definition of hard_smp_processor_id for the UP case to
architecture-specific code ("asm/smp.h") where it belongs, so that each
architecture can provide its own implementation.
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Cc: "Luck, Tony" <tony.luck@intel.com> Acked-by: Andi Kleen <ak@suse.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dave Gilbert [Wed, 9 May 2007 09:33:24 +0000 (02:33 -0700)]
Display all possible partitions when the root filesystem failed to mount
Display all possible partitions when the root filesystem is not mounted.
This helps to track spell'o's and missing drivers.
Updated to work with newer kernels.
Example output:
VFS: Cannot open root device "foobar" or unknown-block(0,0)
Please append a correct "root=" boot option; here are the available partitions:
0800 8388608 sda driver: sd
0801 192748 sda1
0802 8193150 sda2
0810 4194304 sdb driver: sd
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
[akpm@linux-foundation.org: cleanups, fix printk warnings] Signed-off-by: Jan Engelhardt <jengelh@gmx.de> Cc: Dave Gilbert <linux@treblig.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Miklos Szeredi [Wed, 9 May 2007 09:33:22 +0000 (02:33 -0700)]
uml: turn build warnings into comments
These haven't been fixed for ages. Just make comments out of them.
arch/um/kernel/skas/process.c:181:2: warning: #warning Need to look up
+userspace_pid by cpu
arch/um/kernel/skas/process.c:187:2: warning: #warning Need to look up
+userspace_pid by cpu
arch/um/kernel/skas/process.c:194:2: warning: #warning need to loop over
+userspace_pids in kill_off_processes_skas
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jeff Dike [Wed, 9 May 2007 09:33:22 +0000 (02:33 -0700)]
Fix Linuxdoc comment
A linuxdoc comment had fallen out of date - it refers to an argument which no
longer exists.
Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jeff Dike [Wed, 9 May 2007 09:33:21 +0000 (02:33 -0700)]
uml: mark a tt-only function
Mark another function as tt-mode only.
Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Peter Zijlstra [Wed, 9 May 2007 09:33:20 +0000 (02:33 -0700)]
uml: turn on SCSI support
Enable (i)SCSI on UML, dunno why SCSI was deemed broken, it works like a
charm.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jeff Dike [Wed, 9 May 2007 09:33:19 +0000 (02:33 -0700)]
uml: fix build breakage
UML now needs required-features.h to build - an empty one suffices.
Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[ With Johannes Berg <johannes@sipsolutions.net> ]
Separate the hibernation (aka suspend to disk code) from the other suspend
code. In particular:
* Remove the definitions related to hibernation from include/linux/pm.h
* Introduce struct hibernation_ops and a new hibernate() function to hibernate
the system, defined in include/linux/suspend.h
* Separate suspend code in kernel/power/main.c from hibernation-related code
in kernel/power/disk.c and kernel/power/user.c (with the help of
hibernation_ops)
* Switch ACPI (the only user of pm_ops.pm_disk_mode) to hibernation_ops
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Greg KH <greg@kroah.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Nigel Cunningham <nigel@nigel.suspend2.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ken Chen [Wed, 9 May 2007 09:33:09 +0000 (02:33 -0700)]
fix leaky resv_huge_pages when cpuset is in use
The internal hugetlb resv_huge_pages variable can permanently leak nonzero
value in the error path of hugetlb page fault handler when hugetlb page is
used in combination of cpuset. The leaked count can permanently trap N
number of hugetlb pages in unusable "reserved" state.
Steps to reproduce the bug:
(1) create two cpuset, user1 and user2
(2) reserve 50 htlb pages in cpuset user1
(3) attempt to shmget/shmat 50 htlb page inside cpuset user2
(4) kernel oom the user process in step 3
(5) ipcrm the shm segment
At this point resv_huge_pages will have a count of 49, even though
there are no active hugetlbfs file nor hugetlb shared memory segment
in the system. The leak is permanent and there is no recovery method
other than system reboot. The leaked count will hold up all future use
of that many htlb pages in all cpusets.
The culprit is that the error path of alloc_huge_page() did not
properly undo the change it made to resv_huge_page, causing
inconsistent state.
Signed-off-by: Ken Chen <kenchen@google.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Adam Litke <agl@us.ibm.com> Cc: Martin Bligh <mbligh@google.com> Acked-by: David Gibson <dwg@au1.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch removes the possibility of having uninitialized log state if the
log device has failed.
When a mirror resumes operation, it calls 'resume' on the logging module. If
disk based logging is being used, the log device is read to fill in the log
state. If the log device has failed, we cannot simply return, because this
would leave the in-memory log state uninitialized. Instead, we assume all
regions are out-of-sync and reset the log state. Failure to do this could
result in the logging code reporting a region as in-sync, even though it
isn't; which could result in a corrupted mirror.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dm raid1: switch rh_in_sync to blocking in do_reads
The call to rh_in_sync() in do_reads() should be allowed to block. It is in
the mirror worker thread which already permits blocking operations. This will
be needed to support clustered mirroring which will perform network
operations.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dm raid1: fix to commit pending clear region requests
With the code as it is, it is possible for oustanding clear region requests
never to get flushed when a mirror is deactivated or suspended. This means
there will always be some resync work required when a mirror is activated,
even though it may very well be in-sync.
Always requesting the flush doesn't hurt us. This is because the log tracks
whether any changes occurred and, if not, no flush is performed.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
New device-mapper target that can delay I/O (for testing). Reads can be
separated from writes, redirected to different underlying devices and delayed
by differing amounts of time.
Signed-off-by: Heinz Mauelshagen <mauelshagen@redhat.com> Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Delay decrementing the 'struct io' reference count until after the bio has
been freed so that a bio destructor function may reference it. Required by a
later patch.
Signed-off-by: Heinz Mauelshagen <hjm@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Milan Broz <mbroz@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds the ability to specify desired features in the mirror
constructor/mapping table.
The first feature of interest is "handle_errors". Currently, mirroring will
ignore any I/O errors from the devices. Subsequent patches will check for
this flag and handle the errors. If flag/feature is not present, mirror will
do nothing - maintaining backwards compatibility.
Signed-off-by: Jonathan E Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch reports the status of the log device so that userspace can detect
the error and take appropriate action.
Signed-off-by: Jonathan E Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch gives the disk logging code the ability to store the fact that an
error occured on the log device. In addition, an event is raised when an
error is encountered during I/O to the log device.
Signed-off-by: Jonathan E Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Anderson [Wed, 9 May 2007 09:32:57 +0000 (02:32 -0700)]
dm: allow offline devices
Allow check_device_area to succeed if a device has an i_size of zero. This
addresses an issue seen on DASD devices setting up a multipath table for paths
in online and offline state.
Signed-off-by: Mike Anderson <andmike@us.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Olaf Kirch [Wed, 9 May 2007 09:32:54 +0000 (02:32 -0700)]
dm crypt: use smaller bvecs in clones
Allocate smaller clones
With the previous dm-crypt fixes, there is no need for the clone bios to have
the same bvec size as the original - we just need to make them big enough for
the remaining number of pages. The only requirement is that we clear the
"out" index in convert_context, so that crypt_convert starts storing data at
the right position within the clone bio.
Signed-off-by: Olaf Kirch <olaf.kirch@oracle.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Olaf Kirch [Wed, 9 May 2007 09:32:53 +0000 (02:32 -0700)]
dm crypt: fix remove first_clone
Get rid of first_clone in dm-crypt
This gets rid of first_clone, which is not really needed. Apparently, cloned
bios used to share their bvec some time way in the past - this is no longer
the case. Contrarily, this even hurts us if we try to create a clone off
first_clone after it has completed, and crypt_endio has destroyed its bvec.
Signed-off-by: Olaf Kirch <olaf.kirch@oracle.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Olaf Kirch [Wed, 9 May 2007 09:32:52 +0000 (02:32 -0700)]
dm crypt: fix call to clone_init
Call clone_init early
We need to call clone_init as early as possible - at least before call
bio_put(clone) in any error path. Otherwise, the destructor will try to
dereference bi_private, which may still be NULL.
Signed-off-by: Olaf Kirch <olaf.kirch@oracle.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch replaces the single instance of kmirrord by one instance per mirror
set. This change is required to avoid a deadlock in kmirrord when the
persistent dirty log of a mirror itself resides on a mirror. The single
instance of kmirrord then issues a sync write to the dirty log in write_bits
which gets deferred to kmirrord itself later in the call chain. But kmirrord
never does the deferred work because it is still waiting for the sync
write_bits.
_mirror_sets is removed as it no longer needed, and we always flush the
workqueue before destroying it to ensure all work is complete before
destroying it.
Pekka J Enberg [Wed, 9 May 2007 09:32:46 +0000 (02:32 -0700)]
krealloc: fix kerneldoc comments
No "blank" (or "*") line is allowed between the function name and lines for
it parameter(s).
Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SLUB: include lifetime stats and sets of cpus / nodes in tracking output
We have information about how long an object existed and about the nodes and
cpus where the allocations and frees took place. Add that information to the
tracking output in /sys/slab/xx/alloc_calls and /sys/slab/free_calls
This will then enable slabinfo to output nice reports like this:
christoph@qirst:~/slub$ ./slabinfo kmalloc-128
Slabcache: kmalloc-128 Aliases: 0 Order : 0
Sizes (bytes) Slabs Debug Memory
------------------------------------------------------------------------
Object : 128 Total : 12 Sanity Checks : On Total: 49152
SlabObj: 200 Full : 7 Redzoning : On Used : 24832
SlabSiz: 4096 Partial: 4 Poisoning : On Loss : 24320
Loss : 72 CpuSlab: 1 Tracking : On Lalig: 13968
Align : 8 Objects: 20 Tracing : Off Lpadd: 1152
CONFIG_SLUB_DEBUG can be used to switch off the debugging and sysfs components
of SLUB. Thus SLUB will be able to replace SLOB. SLUB can arrange objects in
a denser way than SLOB and the code size should be minimal without debugging
and sysfs support.
Note that CONFIG_SLUB_DEBUG is materially different from CONFIG_SLAB_DEBUG.
CONFIG_SLAB_DEBUG is used to enable slab debugging in SLAB. SLUB enables
debugging via a boot parameter. SLUB debug code should always be present.
CONFIG_SLUB_DEBUG can be modified in the embedded config section.
Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This replaces the PageError() checking. DebugSlab is clearer and allows for
future changes to the page bit used. We also need it to support
CONFIG_SLUB_DEBUG.
Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Its only purpose was to bring some sort of symmetry to sysfs usage when
dealing with bootstrapping per cpu flushing. Since we do not time out slabs
anymore we have no need to run finish_bootstrap even without sysfs. Fold it
back into slab_sysfs_init and drop the initcall for the !SYFS case.
Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-e Show empty slabs
-d Modification of slab debug options at runtime
-o Operations. Display of ctor / dtor etc.
-r Report: Display all available information about a slabcache.
Cleanup tracking display and make it work right.
Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SLUB: add support for dynamic cacheline size determination
SLUB currently assumes that the cacheline size is static. However, i386 f.e.
supports dynamic cache line size determination.
Use cache_line_size() instead of L1_CACHE_BYTES in the allocator.
That also explains the purpose of SLAB_HWCACHE_ALIGN. So we will need to keep
that one around to allow dynamic aligning of objects depending on boot
determination of the cache line size.
[akpm@linux-foundation.org: need to define it before we use it] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
H. Peter Anvin [Wed, 9 May 2007 03:37:02 +0000 (20:37 -0700)]
Documentation/i386/boot.txt: update and correct
In the process of rewriting the x86 setup code, I found a number of
inaccuracies and outdated recommendations in the boot protocol
documentation. Revamp to make it more up to date.
In particular, the common use of the heap actually requires (slightly)
more than 4K of heap plus stack, which is the recommended amount in
the document; currently the code compensates by being smaller than
specified, but we can't assume that will be true forever. Thus,
recommend that if we have a modern bzImage kernel, that the bootloader
maximizes the available space.
Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This will fail to wake up a runqueue for a task that has been migrated to the
expired array of a runqueue which is otherwise idle which can happen with smp
balancing,
Cc: Dmitry Adamushko <dmitry.adamushko@gmail.com> Cc: Con Kolivas <kernel@kolivas.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jean Delvare [Wed, 9 May 2007 03:27:05 +0000 (20:27 -0700)]
applesmc: Use standard sysfs names for labels
We have a standard suffix to associate a designation string to a sensor:
_label. Use it instead of _position so that libsensors will catch it.
(This isn't implemented yet, but should be soon.)
Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Nicolas Boichat <nicolas@boichat.ch> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
projects / linux-2.6 / log