Move all the pseries kexec code into one file, platforms/pseries/kexec.c
Provide helpers for setting up ppc_md.kexec_cpu_down, so that we don't
have to have #ifdef CONFIG_KEXEC in setup.c
Move the initialisation of the ppc_md kexec callbacks into an init routine.
This is well and truly early enough to cause no change in behaviour, we
can't kexec until userspace has given us a kernel to kexec into.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
Move some extern declarations from setup.c into the new pseries.h.
While we're at it, provide dummy implementations for !SMP, to avoid
cluttering the C file with more #ifdefs.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
[POWERPC] Consolidate pseries platform header files into pseries.h
Following the example of platforms/pasemi, consolidate a couple of
tiny header files in platforms/pseries into pseries.h.
This gives us a convenient place to put things that need to be
available to the platform code, but not public. And hopefully will
help people resist the temptation of sticking externs in C files.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
The code was setting up the debug bus for group 21 when profiling on the
event PPU CYCLES. The debug bus is not actually used by the hardware
performance counters when counting PPU CYCLES. Setting up the debug bus
for PPU CYCLES causes signal routing conflicts on the debug bus when
profiling PPU cycles and another PPU event. This patch fixes the code to
only setup the debug bus to route the performance signals for the non
PPU CYCLE events.
Signed-off-by: Maynard Johnson <mpjohn@us.ibm.com> Signed-off-by: Carl Love <carll@us.ibm.com> Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Carl Love [Tue, 13 Feb 2007 21:02:02 +0000 (22:02 +0100)]
[POWERPC] cell: PPU Oprofile cleanup patch
This is a clean up patch that includes the following changes:
-Some comments were added to clarify the code based on feedback
from the community.
-The write_pm_cntrl() and set_count_mode() were passed a
structure element from a global variable. The argument was
removed so the functions now just operate on the global directly.
-The set_pm_event() function call in the cell_virtual_cntr()
routine was moved to a for-loop before the for_each_cpu loop
Signed-off-by: Carl Love <carll@us.ibm.com> Signed-off-by: Maynard Johnson <mpjohn@us.ibm.com> Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Masato Noguchi [Tue, 13 Feb 2007 20:54:30 +0000 (21:54 +0100)]
[POWERPC] spufs: avoid accessing kernel memory through mmapped /mem node
I found an exploit in current kernel.
Currently, there is no range check about mmapping "/mem" node in
spufs. Thus, an application can access privilege memory region.
In case this kernel already worked on a public server, I send this
information only here.
If there are such servers in somewhere, please replace it, ASAP.
[POWERPC] spu sched: static timeslicing for SCHED_RR contexts
For SCHED_RR tasks we can do some really trivial timeslicing. Basically
we fire up a time for every scheduler tick that searches for a higher
or same priority thread that is on the runqueue and if there is one
context switches to it. Because we can't lock spus from timer context
we actually run this from a delayed runqueue instead of a timer.
A nice optimization would be to skip the actual priority bitmap search
when there are less contexts than physical spus available. To implement
this I need a so far unpublished patch from Andre, and it will be added
after we have that patch in.
Note that right now we only do the time slicing for SCHED_RR tasks.
The code would work for SCHED_OTHER tasks aswell, but their prio
value is defered from the one the PPU thread has at time of spu_run,
and using this for spu scheduling decisions would make the code very
unfair. SCHED_OTHER support will be enabled once we the spu scheduler
knows how to calculcate cpu_context.prio (very soon)
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
[POWERPC] spu sched: forced preemption at execution
If we start a spu context with realtime priority we want it to run
immediately and not wait until some other lower priority thread has
finished. Try to find a suitable victim and use it's spu in this
case.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Give spu_yield a kerneldoc comment and remove the old comment
documenting spu_activate, spu_deactive and spu_yield as all of them
now have descriptive kerneldoc comments of their own.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
If we call spu_remove_from_active_list that spu is always guaranteed
to be on the active list and in runnable state, so we can simply
do a list_del to remove it and unconditionally take the was_active
codepath.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
This is the biggest patch in this series, and it reworks the guts of
the spu scheduler runqueue mechanism:
- instead of embedding a waitqueue in the runqueue there is now a
simple doubly-linked list, the actual wakeups happen by reusing
the stop_wq in the spu context (maybe we should rename it one day)
- spu_free and spu_prio_wakeup are merged into a single spu_reschedule
function
- various functionality is split out into small helpers, and kerneldoc
comments are added in various places to document what's going on.
- spu_activate is rewritten into a tight loop by removing test for
various impossible conditions and using the infrastructure in this
patch.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Various cleanups in code surrounding the state semaphore:
- inline spu_acquire/spu_release
- cleanup spu_acquire_* and add kerneldoc comments to these functions
- remove spu_release_exclusive and replace it with spu_release
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
The r/w semaphore to lock the spus was overkill and can be replaced
with a mutex to make it faster, simpler and easier to debug. It also
helps to allow making most spufs interruptible in future patches.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Various cleanups to sched.c that don't change the global control flow:
- add kerneldoc comments to various functions
- add spu_ prefixes to various functions
- add/remove context from the runqueue in bind/unbind_context as
it's part of the logical operation
- add a call to put_active_spu to spu_unbind_contex as it's logically
part of the unbind operation
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Only bind_context/unbind_context change the spu context state. Thus
we can move all assignents of SPU_STATE_RUNNABLE into bind_context,
which parallels the unbind side aswell.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Timur Tabi [Fri, 9 Feb 2007 16:01:50 +0000 (10:01 -0600)]
[POWERPC] 83xx: Updated mpc834x_itx_defconfig
This patch updates the defconfig for the MPC8349E-mITX. In addition to picking
up changes from recent kernels, disables support for e100 (which doesn't ship
with the system), turns off input devices, turns on some I2C support, turns
off HW monitoring (HW not yet supported), turns off OHCI USB (not used), turns
off USB gadget support (HW not yet supported), turns on DOS FS support, and
turns off kernel debugging.
Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
[POWERPC] spufs: Fix bitrot of the SPU mmap facility
It looks like we've had some serious bitrot there mostly due to tracking
of address_space's of mmap'ed files getting out of sync with the actual
mmap code. The mfc, mss and psmap were not tracked properly and thus
not invalidated on context switches (oops !)
I also removed the various file->f_mapping = inode->i_mapping;
assignments that were done in the other open() routines since that
is already done for us by __dentry_open.
One improvement we might want to do later is to assign the various
ctx-> fields at mmap time instead of file open/close time so that we
don't call unmap_mapping_range() on thing that have not been mmap'ed
Finally, I added some smp_wmb's after assigning the ctx-> fields to make
sure they are visible to other CPUs. I don't think this is really
necessary as I suspect locking in the fs layer will make that happen
anyway but better safe than sorry.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
[POWERPC] spufs: remove need for struct page for SPEs
This patch removes the need for struct page for SPE local store
and registers from spufs. It also makes the locking much more
obvious and no longer relying on the truncate logic black magic
for protecting against races between unmap_mapping_range() and
new pages faulted in. It does so by switching to a nopfn() handler
and using the new vm_insert_pfn() to setup the PTEs itself while
holding a lock on the SPE.
The nice thing is that this patch actually removes a lot more code
than it adds :-)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Sylvain Munaut [Mon, 12 Feb 2007 22:13:24 +0000 (23:13 +0100)]
[POWERPC] Small cleanup of EFIKA platform
The efika platform used three files efika-pci.c efika-setup.c and
a 2 line efika.h to link the two. The total of code in those is
really not much and therefore, I think they're better merged
in a single file.
There is absolutely _no_code_change_ at all, just merged the files.
Signed-off-by: Sylvain Munaut <tnt@246tNt.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Paul Mackerras <paulus@samba.org>
Sylvain Munaut [Mon, 12 Feb 2007 22:13:21 +0000 (23:13 +0100)]
[POWERPC] Restore 'proper' link order in platform
The 52xx was put before CHRP to allow EFIKA to be recognized
properly. Now the efika tree is fixed up in prom_init so
no need for this ugly hack. So we restore the 'normal'
order.
Signed-off-by: Sylvain Munaut <tnt@246tNt.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Paul Mackerras <paulus@samba.org>
Sylvain Munaut [Mon, 12 Feb 2007 22:13:20 +0000 (23:13 +0100)]
[POWERPC] Add device tree fixups for the EFIKA
We make the efika device tree compliant with the defined bindings
(at least compliant enough). This is mostly done by mangling
the device_type and compatible properties, but also adding
some missing bits.
Signed-off-by: Sylvain Munaut <tnt@246tNt.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Paul Mackerras <paulus@samba.org>
Grant Likely [Mon, 12 Feb 2007 20:36:54 +0000 (13:36 -0700)]
[POWERPC] mpc5200 device tree bindings refinement
Much needed refinement of mpc5200 device tree binding specifications.
Short list:
- drop mpc52xx designator; only two supported chips exist, 5200 and 5200b.
It's premature to refer to them as '52xx'.
- Specify optional 'model' and 'revision' properties in the soc5200 node
- Specify reqiured 'cell-index' property to identify between multiple SOC
devices of the same type. (Useful for arbitrating shared register access)
- Specify optional 'port-number' property for adjusting the logical serial
port assignments.
- Specify optional 'has-wdt' property for gpt0 node.
- Add system-frequency property to soc5200 node
Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Paul Mackerras <paulus@samba.org>
Stefan Roese [Mon, 12 Feb 2007 10:29:04 +0000 (11:29 +0100)]
[POWERPC] ppc: Add support for AMCC Taishan 440GX eval board
This patch adds support for the AMCC Taishan PPC440GX evaluation
board.
This is still an arch/ppc port. I'm aware that the move of
4xx to arch/powerpc is making good progress right now. So this
patch is mainly intended to make the Taishan support available
for the community right now.
Signed-off-by: Stefan Roese <sr@denx.de> Signed-off-by: Paul Mackerras <paulus@samba.org>
The recent vDSO consolidation patches broke powerpc due to a mistake
in the definition of MAXPAGES constants. This fixes it by moving to
a dynamically allocated array of pages instead as I don't like much
hard coded size limits. Also move the vdso initialisation to an initcall
since it doesn't really need to be done -that- early.
Applogies for not catching the breakage earlier, Roland _did_ CC me on
his patches a while ago, I got busy with other things and forgot to test
them.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Olaf Hering [Sat, 10 Feb 2007 20:38:37 +0000 (21:38 +0100)]
[POWERPC] Mark winbond IDE PCI resources with start 0 as unassigned
libata calls pci_request_regions to claim PCI BAR 0 - 5
pci_request_regions fails if one of the regions cant be claimed.
bar 5 has start == 0, __request_resource will fail.
Pavel Fedin [Mon, 29 Jan 2007 12:13:03 +0000 (15:13 +0300)]
[POWERPC] Virtual DMA support for floppy driver for new powerpc architecture
During ppc64+ppc merge virtual DMA code for floppy driver was not
ported. This patch restores virtual DMA support for floppy in new
powerpc target.
It is necessary at least on Pegasos and AmigaOne machines for the
floppy drive to function. ISA DMA controller works incorrectly there
due to its addressing limitations.
Virtual DMA mode is activated by floppy=nodma option passed to the
kernel (or module). There's no automatic switch like on i386.
Signed-off-by: Pavel Fedin <sonic_amiga@rambler.ru> Signed-off-by: Paul Mackerras <paulus@samba.org>
David Gibson [Tue, 6 Feb 2007 01:48:31 +0000 (12:48 +1100)]
[POWERPC] Remove ibm4{xx,4x}.h from arch/powerpc
ARCH=powerpc should not use the ghastly un-multiplatformable tangle of
includes that starts with asm-ppc/ibm4xx.h. This patch removes a
compile-breaking include of it from head_44x.S.
Signed-off-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
Becky Bruce [Mon, 12 Feb 2007 23:43:46 +0000 (17:43 -0600)]
[POWERPC] 85xx: Don't write reserved values to MAS1[TSIZE]
Some of the current tlbwe instructions early on in head_fsl_booke.S take
advantage of unarchitected behavior that allows the writing of reserved
values to the TSIZE field. This patch corrects that, as well as an error
where an uninitialized (by linux) value was written into a MAS register and
used for a tlbwe.
Correct this for both arch/ppc and arch/powerpc.
Signed-off-by: Becky Bruce <becky.bruce@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
* master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6:
[SPARC]: Re-export saved_command_line to modules.
[SPARC64]: Increase command line size to 2048 like other arches.
[SPARC64]: We do not need ZONE_DMA.
[NETFILTER]: ip6t_mh: drop piggyback payload packet on MH packets
Regarding RFC3775, MH payload proto field should be IPPROTO_NONE. Otherwise
it must be discarded (and the receiver should send ICMP error).
We assume filter should drop such piggyback everytime to disallow slipping
through firewall rules, even the final receiver will discard it.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Patrick McHardy [Mon, 12 Feb 2007 19:14:28 +0000 (11:14 -0800)]
[NETFILTER]: nf_conntrack: change nf_conntrack_l[34]proto_unregister to void
No caller checks the return value, and since its usually called within the
module unload path there's nothing a module could do about errors anyway,
so BUG on invalid conditions and return void.
Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
NF_CT_STAT_INC assumes rcu_read_lock in nf_hook_slow disables
preemption as well, making it legal to use __get_cpu_var without
disabling preemption manually. The assumption is not correct anymore
with preemptable RCU, additionally we need to protect against softirqs
when not holding nf_conntrack_lock.
Add NF_CT_STAT_INC_ATOMIC macro, which disables local softirqs,
and use where necessary.
Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
CONNTRACK_STAT_INC assumes rcu_read_lock in nf_hook_slow disables
preemption as well, making it legal to use __get_cpu_var without
disabling preemption manually. The assumption is not correct anymore
with preemptable RCU, additionally we need to protect against softirqs
when not holding ip_conntrack_lock.
Add CONNTRACK_STAT_INC_ATOMIC macro, which disables local softirqs,
and use where necessary.
Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Patrick McHardy [Mon, 12 Feb 2007 19:12:57 +0000 (11:12 -0800)]
[NETFILTER]: nf_conntrack: properly use RCU API for nf_ct_protos/nf_ct_l3protos arrays
Replace preempt_{enable,disable} based RCU by proper use of the
RCU API and add missing rcu_read_lock/rcu_read_unlock calls in
all paths not obviously only used within packet process context
(nfnetlink_conntrack).
Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Patrick McHardy [Mon, 12 Feb 2007 19:12:40 +0000 (11:12 -0800)]
[NETFILTER]: ip_conntrack: properly use RCU API for ip_ct_protos array
Replace preempt_{enable,disable} based RCU by proper use of the
RCU API and add missing rcu_read_lock/rcu_read_unlock calls in
all paths not obviously only used within packet process context
(nfnetlink_conntrack).
Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Patrick McHardy [Mon, 12 Feb 2007 19:12:26 +0000 (11:12 -0800)]
[NETFILTER]: nf_nat: properly use RCU API for nf_nat_protos array
Replace preempt_{enable,disable} based RCU by proper use of the
RCU API and add missing rcu_read_lock/rcu_read_unlock calls in
paths used outside of packet processing context (nfnetlink_conntrack).
Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Patrick McHardy [Mon, 12 Feb 2007 19:12:09 +0000 (11:12 -0800)]
[NETFILTER]: ip_nat: properly use RCU API for ip_nat_protos array
Replace preempt_{enable,disable} based RCU by proper use of the
RCU API and add missing rcu_read_lock/rcu_read_unlock calls in
paths used outside of packet processing context (nfnetlink_conntrack).
Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Patrick McHardy [Mon, 12 Feb 2007 19:11:24 +0000 (11:11 -0800)]
[NETFILTER]: nf_log: make nf_log_unregister_pf return void
Since the only user of nf_log_unregister_pf (nfnetlink_log) doesn't
check the return value, change it to void and bail out silently when
a non-existant address family is supplied.
Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Patrick McHardy [Mon, 12 Feb 2007 19:09:19 +0000 (11:09 -0800)]
[NETFILTER]: Properly use RCU in nf_ct_attach
Use rcu_assign_pointer/rcu_dereference for ip_ct_attach pointer instead
of self-made RCU and use rcu_read_lock to make sure the conntrack module
doesn't disappear below us while calling it, since this function can be
called from outside the netfilter hooks.
Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Linus Torvalds [Mon, 12 Feb 2007 17:57:44 +0000 (09:57 -0800)]
Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6
* 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6:
[S390] remove __io_virt and mmiowb.
[S390] cio: use ARRAY_SIZE in device_id.c
[S390] cio: Fixup interface for setting options on ccw devices.
[S390] smp_call_function/smp_call_function_on locking.
Arjan van de Ven [Mon, 12 Feb 2007 08:55:40 +0000 (00:55 -0800)]
[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 <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Arjan van de Ven [Mon, 12 Feb 2007 08:55:39 +0000 (00:55 -0800)]
[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 <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Arjan van de Ven [Mon, 12 Feb 2007 08:55:38 +0000 (00:55 -0800)]
[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 <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Arjan van de Ven [Mon, 12 Feb 2007 08:55:37 +0000 (00:55 -0800)]
[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 <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Arjan van de Ven [Mon, 12 Feb 2007 08:55:36 +0000 (00:55 -0800)]
[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 <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Arjan van de Ven [Mon, 12 Feb 2007 08:55:35 +0000 (00:55 -0800)]
[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 <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Arjan van de Ven [Mon, 12 Feb 2007 08:55:34 +0000 (00:55 -0800)]
[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 <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Arjan van de Ven [Mon, 12 Feb 2007 08:55:34 +0000 (00:55 -0800)]
[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 <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
projects / linux-2.6 / log