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Tim and Ananiev report that the recent WARN_ON_ONCE changes cause increased
cache misses with the tbench workload. Apparently due to the access to the
newly-added static variable.
Rearrange the code so that we don't touch that variable unless the warning is
going to trigger.
Also rework the logic so that the static variable starts out at zero, so we
can move it into bss.
It would seem logical to mark the static variable as __read_mostly too. But
it would be wrong, because that would put it back into the vmlinux image, and
the kernel will never read from this variable in normal operation anyway.
Unless the compiler or hardware go and do some prefetching on us?
For some reason this patch shrinks softirq.o text by 40 bytes.
Cc: Tim Chen <tim.c.chen@intel.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "Ananiev, Leonid I" <leonid.i.ananiev@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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David Woodhouse points out that the comment accompanying the MTFSF_L
macro is misleading. We should make it clear that the L bit is ignored
on older CPUS, not the entire instruction.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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Signed-off-by: Paul Mackerras <paulus@samba.org>
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Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.
The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around. On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).
Where appropriate, an arch may override the generic storage facility and do
something different with the variable. On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.
Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions. Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller. A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.
I've build this code with allyesconfig for x86_64 and i386. I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.
This will affect all archs. Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:
struct pt_regs *old_regs = set_irq_regs(regs);
And put the old one back at the end:
set_irq_regs(old_regs);
Don't pass regs through to generic_handle_irq() or __do_IRQ().
In timer_interrupt(), this sort of change will be necessary:
- update_process_times(user_mode(regs));
- profile_tick(CPU_PROFILING, regs);
+ update_process_times(user_mode(get_irq_regs()));
+ profile_tick(CPU_PROFILING);
I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().
Some notes on the interrupt handling in the drivers:
(*) input_dev() is now gone entirely. The regs pointer is no longer stored in
the input_dev struct.
(*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
something different depending on whether it's been supplied with a regs
pointer or not.
(*) Various IRQ handler function pointers have been moved to type
irq_handler_t.
Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
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Typedef the IRQ handler function type.
Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1356d1e5fd256997e3d3dce0777ab787d0515c7a commit)
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Typedef the IRQ flow handler function type.
Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 8e973fbdf5716b93a0a8c0365be33a31ca0fa351 commit)
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* git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
[POWERPC] cell: fix bugs found by sparse
[POWERPC] spiderpic: enable new style devtree support
[POWERPC] Update cell_defconfig
[POWERPC] spufs: add infrastructure for finding elf objects
[POWERPC] spufs: support new OF device tree format
[POWERPC] spufs: add support for read/write on cntl
[POWERPC] spufs: remove support for ancient firmware
[POWERPC] spufs: make mailbox functions handle multiple elements
[POWERPC] spufs: use correct pg_prot for mapping SPU local store
[POWERPC] spufs: Add infrastructure needed for gang scheduling
[POWERPC] spufs: implement error event delivery to user space
[POWERPC] spufs: fix context switch during page fault
[POWERPC] spufs: scheduler support for NUMA.
[POWERPC] spufs: cell spu problem state mapping updates
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* master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (54 commits)
[SCSI] Initial Commit of qla4xxx
[SCSI] raid class: handle component-add errors
[SCSI] SCSI megaraid_sas: handle thrown errors
[SCSI] SCSI aic94xx: handle sysfs errors
[SCSI] SCSI st: fix error handling in module init, sysfs
[SCSI] SCSI sd: fix module init/exit error handling
[SCSI] SCSI osst: add error handling to module init, sysfs
[SCSI] scsi: remove hosts.h
[SCSI] scsi: Scsi_Cmnd convertion in aic7xxx_old.c
[SCSI] megaraid_sas: sets ioctl timeout and updates version,changelog
[SCSI] megaraid_sas: adds tasklet for cmd completion
[SCSI] megaraid_sas: prints pending cmds before setting hw_crit_error
[SCSI] megaraid_sas: function pointer for disable interrupt
[SCSI] megaraid_sas: frame count optimization
[SCSI] megaraid_sas: FW transition and q size changes
[SCSI] qla2xxx: Update version number to 8.01.07-k2.
[SCSI] qla2xxx: Stall mid-layer error handlers while rport is blocked.
[SCSI] qla2xxx: Add MODULE_FIRMWARE tags.
[SCSI] qla2xxx: Add support for host port state FC transport attribute.
[SCSI] qla2xxx: Add support for fabric name FC transport attribute.
...
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This adds an 'object-id' file that the spe library can
use to store a pointer to its ELF object. This was
originally meant for use by oprofile, but is now
also used by the GNU debugger, if available.
In order for oprofile to find the location in an spu-elf
binary where an event counter triggered, we need a way
to identify the binary in the first place.
Unfortunately, that binary itself can be embedded in a
powerpc ELF binary. Since we can assume it is mapped into
the effective address space of the running process,
have that one write the pointer value into a new spufs
file.
When a context switch occurs, pass the user value to
the profiler so that can look at the mapped file (with
some care).
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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Add the concept of a gang to spufs as a new type of object.
So far, this has no impact whatsover on scheduling, but makes
it possible to add that later.
A new type of object in spufs is now a spu_gang. It is created
with the spu_create system call with the flags argument set
to SPU_CREATE_GANG (0x2). Inside of a spu_gang, it
is then possible to create spu_context objects, which until
now was only possible at the root of spufs.
There is a new member in struct spu_context pointing to
the spu_gang it belongs to, if any. The spu_gang maintains
a list of spu_context structures that are its children.
This information can then be used in the scheduler in the
future.
There is still a bug that needs to be resolved in this
basic infrastructure regarding the order in which objects
are removed. When the spu_gang file descriptor is closed
before the spu_context descriptors, we leak the dentry
and inode for the gang. Any ideas how to cleanly solve
this are appreciated.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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This tries to fix spufs so we have an interface closer to what is
specified in the man page for events returned in the third argument of
spu_run.
Fortunately, libspe has never been using the returned contents of that
register, as they were the same as the return code of spu_run (duh!).
Unlike the specification that we never implemented correctly, we now
require a SPU_CREATE_EVENTS_ENABLED flag passed to spu_create, in
order to get the new behavior. When this flag is not passed, spu_run
will simply ignore the third argument now.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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This patch adds NUMA support to the the spufs scheduler.
The new arch/powerpc/platforms/cell/spufs/sched.c is greatly
simplified, in an attempt to reduce complexity while adding
support for NUMA scheduler domains. SPUs are allocated starting
from the calling thread's node, moving to others as supported by
current->cpus_allowed. Preemption is gone as it was buggy, but
should be re-enabled in another patch when stable.
The new arch/powerpc/platforms/cell/spu_base.c maintains idle
lists on a per-node basis, and allows caller to specify which
node(s) an SPU should be allocated from, while passing -1 tells
spu_alloc() that any node is allowed.
Since the patch removes the currently implemented preemptive
scheduling, it is technically a regression, but practically
all users have since migrated to this version, as it is
part of the IBM SDK and the yellowdog distribution, so there
is not much point holding it back while the new preemptive
scheduling patch gets delayed further.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
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Use page_to_phys and pfn_to_page to avoid open-coded mem_map usage.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
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The include of linux/smp.h needs to be done before the #if that
checks for the compiler version. Seems like fallout from the
inline assembly cleanup patch vs. the directed yield patch.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
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* 'for-2.6.19' of git://brick.kernel.dk/data/git/linux-2.6-block:
[PATCH] Document bi_sector and sector_t
[PATCH] helper function for retrieving scsi_cmd given host based block layer tag
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* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
[MIPS] Remove remaining reference to ite_gpio.h from Kbuild
[MIPS] PNX8550 fixups
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Signed-Off-By: Roger Gammans <rgammans@computer-surgery.co.uk>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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This was necessitated by the need for a function to get back
to a scsi_cmnd, when an hba the posts its (corresponding) completion
interrupt with a block layer tag as its reference.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: David Somayajulu <david.somayajulu@qlogic.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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Allow the board to remap actual USART peripheral devices to serial
devices by calling at32_map_usart(hw_id, serial_line). This ensures
that even though ATSTK1002 uses USART1 as the first serial port, it
will still have a ttyS0 device.
This also adds a board-specific early setup hook and moves the
at32_setup_serial_console() call there from the platform code.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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In order to initialize the serial console early, the atmel_serial
driver had to do a hack where it compared the physical address of the
port with an address known to be permanently mapped, and used it as a
virtual address. This got around the limitation that ioremap() isn't
always available when the console is being initalized.
This patch removes that hack and replaces it with a new "regs" field
in struct atmel_uart_data that the board-specific code can initialize
to a fixed virtual mapping for platform devices where this is possible.
It also initializes the DBGU's regs field with the address the driver
used to check against.
On AVR32, the "regs" field is initialized from the physical base
address when this it can be accessed through a permanently 1:1 mapped
segment, i.e. the P4 segment.
If regs is NULL, the console initialization is delayed until the "real"
driver is up and running and ioremap() can be used.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Rename at91_register_uart_fns and associated structs and variables
to make it consistent with the atmel_ prefix used by the rest of
the driver.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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The at91_serial driver can be used with both AT32 and AT91 devices
from Atmel and has therefore been renamed atmel_serial. The only
thing left is to rename PORT_AT91 PORT_ATMEL.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Rename the following public definitions:
* AT91_NR_UART -> ATMEL_MAX_UART
* struct at91_uart_data -> struct atmel_uart_data
* at91_default_console_device -> atmel_default_console_device
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Rename the following Kconfig symbols:
* CONFIG_SERIAL_AT91 -> CONFIG_SERIAL_ATMEL
* CONFIG_SERIAL_AT91_CONSOLE -> CONFIG_SERIAL_ATMEL_CONSOLE
* CONFIG_SERIAL_AT91_TTYAT -> CONFIG_SERIAL_ATMEL_TTYAT
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Move include/asm/arch/at91rm9200_usart.h into drivers/serial and rename
it atmel_usart.h. Also delete AVR32's version of this file.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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This patch fixes the compilation errors on PNX8550 and hard-to-track
bug in interrupt handling.
It also corresponds to the latest changes in PNX8550 serial driver.
Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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* master.kernel.org:/pub/scm/linux/kernel/git/davej/configh:
Remove all inclusions of <linux/config.h>
Manually resolved trivial path conflicts due to removed files in
the sound/oss/ subdirectory.
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* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6: (292 commits)
[GFS2] Fix endian bug for de_type
[GFS2] Initialize SELinux extended attributes at inode creation time.
[GFS2] Move logging code into log.c (mostly)
[GFS2] Mark nlink cleared so VFS sees it happen
[GFS2] Two redundant casts removed
[GFS2] Remove uneeded endian conversion
[GFS2] Remove duplicate sb reading code
[GFS2] Mark metadata reads for blktrace
[GFS2] Remove iflags.h, use FS_
[GFS2] Fix code style/indent in ops_file.c
[GFS2] streamline-generic_file_-interfaces-and-filemap gfs fix
[GFS2] Remove readv/writev methods and use aio_read/aio_write instead (gfs bits)
[GFS2] inode-diet: Eliminate i_blksize from the inode structure
[GFS2] inode_diet: Replace inode.u.generic_ip with inode.i_private (gfs)
[GFS2] Fix typo in last patch
[GFS2] Fix direct i/o logic in filemap.c
[GFS2] Fix bug in Makefiles for lock modules
[GFS2] Remove (extra) fs_subsys declaration
[GFS2/DLM] Fix trailing whitespace
[GFS2] Tidy up meta_io code
...
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* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
[XFRM]: BEET mode
[TCP]: Kill warning in tcp_clean_rtx_queue().
[NET_SCHED]: Remove old estimator implementation
[ATM]: [zatm] always *pcr in alloc_shaper()
[ATM]: [ambassador] Change the return type to reflect reality
[ATM]: kmalloc to kzalloc patches for drivers/atm
[TIPC]: fix printk warning
[XFRM]: Clearing xfrm_policy_count[] to zero during flush is incorrect.
[XFRM] STATE: Use destination address for src hash.
[NEIGH]: always use hash_mask under tbl lock
[UDP]: Fix MSG_PROBE crash
[UDP6]: Fix flowi clobbering
[NET_SCHED]: Revert "HTB: fix incorrect use of RB_EMPTY_NODE"
[NETFILTER]: ebt_mark: add or/and/xor action support to mark target
[NETFILTER]: ipt_REJECT: remove largely duplicate route_reverse function
[NETFILTER]: Honour source routing for LVS-NAT
[NETFILTER]: add type parameter to ip_route_me_harder
[NETFILTER]: Kconfig: fix xt_physdev dependencies
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* master.kernel.org:/pub/scm/linux/kernel/git/willy/parisc-2.6: (41 commits)
[PARISC] Kill wall_jiffies use
[PARISC] Honour "panic_on_oops" sysctl
[PARISC] Fix fs/binfmt_som.c
[PARISC] Export clear_user_page to modules
[PARISC] Make DMA routines more stubby
[PARISC] Define pci_get_legacy_ide_irq
[PARISC] Fix CONFIG_DEBUG_SPINLOCK
[PARISC] Fix HPUX compat compile with current GCC
[PARISC] Fix iounmap compile warning
[PARISC] Add support for Quicksilver AGPGART
[PARISC] Move LBA and SBA register defines to the common ropes.h
[PARISC] Create shared <asm/ropes.h> header
[PARISC] Stash the lba_device in its struct device drvdata
[PARISC] Generalize IS_ASTRO et al to take a parisc_device like
[PARISC] Pretty print the name of the lba type on kernel boot
[PARISC] Remove some obsolete comments and I checked that Reo is similar to Ike
[PARISC] Add hardware found in the rp8400
[PARISC] Allow nested interrupts
[PARISC] Further updates to timer_interrupt()
[PARISC] remove halftick and copy clocktick to local var (gcc can optimize usage)
...
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* git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (25 commits)
[POWERPC] Add support for the mpc832x mds board
[POWERPC] Add initial support for the e300c2 core
[POWERPC] Add MPC8360EMDS default dts file
[POWERPC] Add MPC8360EMDS board support
[POWERPC] Add QUICC Engine (QE) infrastructure
[POWERPC] Add QE device tree node definition
[POWERPC] Don't try to just continue if xmon has no input device
[POWERPC] Fix a printk in pseries_mpic_init_IRQ
[POWERPC] Get default baud rate in udbg_scc
[POWERPC] Fix zImage.coff on oldworld PowerMac
[POWERPC] Fix xmon=off and cleanup xmon initialisation
[POWERPC] Cleanup include/asm-powerpc/xmon.h
[POWERPC] Update swim3 printk after blkdev.h change
[POWERPC] Cell interrupt rework
POWERPC: mpc82xx merge: board-specific/platform stuff(resend)
POWERPC: 8272ads merge to powerpc: common stuff
POWERPC: Added devicetree for mpc8272ads board
[POWERPC] iSeries has no legacy I/O
[POWERPC] implement BEGIN/END_FW_FTR_SECTION
[POWERPC] iSeries does not need pcibios_fixup_resources
...
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current
* 'audit.b32' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current:
[PATCH] message types updated
[PATCH] name_count array overrun
[PATCH] PPID filtering fix
[PATCH] arch filter lists with < or > should not be accepted
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master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev
* 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev:
[libata] pata_artop: kill gcc warning
[PATCH] libata: turn off NCQ if queue depth is adjusted to 1
[PATCH] libata: cosmetic changes to constants
[libata] DocBook minor updates, fixes
[libata] PCI ID table cleanup in various drivers
[libata] Print out Status register, if a BSY-sleep takes too long
[libata] init probe_ent->private_data in a common location
[libata] minor PCI IDE probe fixes and cleanups
[libata] Use new PCI_VDEVICE() macro to dramatically shorten ID lists
[PATCH] Fix reference of uninitialised memory in ata_device_add()
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This patch contains the scheduled removal of OSS drivers that:
- have ALSA drivers for the same hardware without known regressions and
- whose Kconfig options have been removed in 2.6.17.
[michal.k.k.piotrowski@gmail.com: build fix]
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Add MAINTAINERS entry for Read-Copy Update (RCU), listing Dipankar Sarma as
maintainer, and giving the URL for Paul McKenney's RCU site. Add
MAINTAINERS entry for rcutorture, listing myself as maintainer. Add
CREDITS entries for developers of RCU, RCU variants, and rcutorture. Use
Paul McKenney's preferred email address in include/linux/rcupdate.h .
Signed-off-by: Josh Triplett <josh@freedesktop.org>
Cc: Paul McKenney <paulmck@us.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Kill a hard-to-calculate 'rsinterval' boot parameter and per-cpu
rcu_data.last_rs_qlen. Instead, it adds adds a flag rcu_ctrlblk.signaled,
which records the fact that one of CPUs has sent a resched IPI since the
last rcu_start_batch().
Roughly speaking, we need two rcu_start_batch()s in order to move callbacks
from ->nxtlist to ->donelist. This means that when ->qlen exceeds qhimark
and continues to grow, we should send a resched IPI, and then do it again
after we gone through a quiescent state.
On the other hand, if it was already sent, we don't need to do it again
when another CPU detects overflow of the queue.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Currently the init_srcu_struct() routine has no way to report out-of-memory
errors. This patch (as761) makes it return -ENOMEM when the per-cpu data
allocation fails.
The patch also makes srcu_init_notifier_head() report a BUG if a notifier
head can't be initialized. Perhaps it should return -ENOMEM instead, but
in the most likely cases where this might occur I don't think any recovery
is possible. Notifier chains generally are not created dynamically.
[akpm@osdl.org: avoid statement-with-side-effect in macro]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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This patch (as751) adds a new type of notifier chain, based on the SRCU
(Sleepable Read-Copy Update) primitives recently added to the kernel. An
SRCU notifier chain is much like a blocking notifier chain, in that it must
be called in process context and its callout routines are allowed to sleep.
The difference is that the chain's links are protected by the SRCU
mechanism rather than by an rw-semaphore, so calling the chain has
extremely low overhead: no memory barriers and no cache-line bouncing. On
the other hand, unregistering from the chain is expensive and the chain
head requires special runtime initialization (plus cleanup if it is to be
deallocated).
SRCU notifiers are appropriate for notifiers that will be called very
frequently and for which unregistration occurs very seldom. The proposed
"task notifier" scheme qualifies, as may some of the network notifiers.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
Acked-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Updated patch adding a variant of RCU that permits sleeping in read-side
critical sections. SRCU is as follows:
o Each use of SRCU creates its own srcu_struct, and each
srcu_struct has its own set of grace periods. This is
critical, as it prevents one subsystem with a blocking
reader from holding up SRCU grace periods for other
subsystems.
o The SRCU primitives (srcu_read_lock(), srcu_read_unlock(),
and synchronize_srcu()) all take a pointer to a srcu_struct.
o The SRCU primitives must be called from process context.
o srcu_read_lock() returns an int that must be passed to
the matching srcu_read_unlock(). Realtime RCU avoids the
need for this by storing the state in the task struct,
but SRCU needs to allow a given code path to pass through
multiple SRCU domains -- storing state in the task struct
would therefore require either arbitrary space in the
task struct or arbitrary limits on SRCU nesting. So I
kicked the state-storage problem up to the caller.
Of course, it is not permitted to call synchronize_srcu()
while in an SRCU read-side critical section.
o There is no call_srcu(). It would not be hard to implement
one, but it seems like too easy a way to OOM the system.
(Hey, we have enough trouble with call_rcu(), which does
-not- permit readers to sleep!!!) So, if you want it,
please tell me why...
[josht@us.ibm.com: sparse notation]
Signed-off-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: Josh Triplett <josh@freedesktop.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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This moves the declarations for the architecture helpers into
include/linux/htirq.h from the generic include/linux/pci.h. Hopefully this
will make this distinction clearer.
htirq.h is included where it is needed.
The dependency on the msi code is fixed and removed.
The Makefile is tidied up.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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It turns out msi_ops was simply not enough to abstract the architecture
specific details of msi. So I have moved the resposibility of constructing
the struct irq_chip to the architectures, and have two architecture specific
functions arch_setup_msi_irq, and arch_teardown_msi_irq.
For simple architectures those functions can do all of the work. For
architectures with platform dependencies they can call into the appropriate
platform code.
With this msi.c is finally free of assuming you have an apic, and this
actually takes less code.
The helpers for the architecture specific code are declared in the linux/msi.h
to keep them separate from the msi functions used by drivers in linux/pci.h
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Currently msi.c is doing sanity checks that make certain before an irq is
destroyed it has no more users.
By adding irq_has_action I can perform the test is a generic way, instead of
relying on a msi specific data structure.
By performing the core check in dynamic_irq_cleanup I ensure every user of
dynamic irqs has a test present and we don't free resources that are in use.
In msi.c this allows me to kill the attrib.state member of msi_desc and all of
the assciated code to maintain it.
To keep from freeing data structures when irq cleanup code is called to soon
changing dyanamic_irq_cleanup is insufficient because there are msi specific
data structures that are also not safe to free.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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This patch implements two functions ht_create_irq and ht_destroy_irq for
use by drivers. Several other functions are implemented as helpers for
arch specific irq_chip handlers.
The driver for the card I tested this on isn't yet ready to be merged.
However this code is and hypertransport irqs are in use in a few other
places in the kernel. Not that any of this will get merged before 2.6.19
Because the ipath-ht400 is slightly out of spec this code will need to be
generalized to work there.
I think all of the powerpc uses are for a plain interrupt controller in a
chipset so support for native hypertransport devices is a little less
interesting.
However I think this is a half way decent model on how to separate arch
specific and generic helper code, and I think this is a functional model of
how to get the architecture dependencies out of the msi code.
[akpm@osdl.org: Kconfig fix]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Greg KH <greg@kroah.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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This adds defines for the hypertransport capability subtypes and starts
using them a little.
[akpm@osdl.org: fix typo]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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With more irqs in the system we don't need this.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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This refactors the irq handling code to make the vectors a per cpu resource so
the same vector number can be simultaneously used on multiple cpus for
different irqs.
This should make systems that were hitting limits on the total number of irqs
much more livable.
[akpm@osdl.org: build fix]
[akpm@osdl.org: __target_IO_APIC_irq is unneeded on UP]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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