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* Merge branch 'locking-core-for-linus' of ↵Linus Torvalds2014-06-03
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next Pull core locking updates from Ingo Molnar: "The main changes in this cycle were: - reduced/streamlined smp_mb__*() interface that allows more usecases and makes the existing ones less buggy, especially in rarer architectures - add rwsem implementation comments - bump up lockdep limits" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits) rwsem: Add comments to explain the meaning of the rwsem's count field lockdep: Increase static allocations arch: Mass conversion of smp_mb__*() arch,doc: Convert smp_mb__*() arch,xtensa: Convert smp_mb__*() arch,x86: Convert smp_mb__*() arch,tile: Convert smp_mb__*() arch,sparc: Convert smp_mb__*() arch,sh: Convert smp_mb__*() arch,score: Convert smp_mb__*() arch,s390: Convert smp_mb__*() arch,powerpc: Convert smp_mb__*() arch,parisc: Convert smp_mb__*() arch,openrisc: Convert smp_mb__*() arch,mn10300: Convert smp_mb__*() arch,mips: Convert smp_mb__*() arch,metag: Convert smp_mb__*() arch,m68k: Convert smp_mb__*() arch,m32r: Convert smp_mb__*() arch,ia64: Convert smp_mb__*() ...
| * arch: Mass conversion of smp_mb__*()Peter Zijlstra2014-04-18
| | | | | | | | | | | | | | | | | | | | | | Mostly scripted conversion of the smp_mb__* barriers. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-arch@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | block/blk-iopoll.c: use iop instead of iopollFabian Frederick2014-05-02
|/ | | | | | | | | | All blk_iopoll functions use iop for parent iopoll structure except blk_iopoll_complete.This also fixes one kernel-doc warning. Cc: Jens Axboe <axboe@kernel.dk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: remove old blk_iopoll_enabled variableJens Axboe2014-03-13
| | | | | | | | | | | | | | | | This was a debugging measure to toggle enabled/disabled when testing. But for real production setups, it's not safe to toggle this setting without either reloading drivers of quiescing IO first. Neither of which the toggle enforces. Additionally, it makes drivers deal with the conditional state. Remove it completely. It's up to the driver whether iopoll is enabled or not. Signed-off-by: Jens Axboe <axboe@fb.com>
* block: Replace __get_cpu_var usesChristoph Lameter2013-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : #define __get_cpu_var(var) (*this_cpu_ptr(&(var))) __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to this_cpu_inc(y) Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: delete __cpuinit usage from all block filesPaul Gortmaker2013-07-14
| | | | | | | | | | | | | | | | | | | | | The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. This removes all the drivers/block uses of the __cpuinit macros from all C files. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tree-wide: fix assorted typos all over the placeAndré Goddard Rosa2009-12-04
| | | | | | | | | | That is "success", "unknown", "through", "performance", "[re|un]mapping" , "access", "default", "reasonable", "[con]currently", "temperature" , "channel", "[un]used", "application", "example","hierarchy", "therefore" , "[over|under]flow", "contiguous", "threshold", "enough" and others. Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* block: use interrupts disabled version of raise_softirq_irqoff()Jens Axboe2009-09-11
| | | | | | | We already have interrupts disabled at that point, so use the __raise_softirq_irqoff() variant. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: fix comment in blk-iopoll.cJens Axboe2009-09-11
| | | | Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: adjust default budget for blk-iopollJens Axboe2009-09-11
| | | | | | It's not exported, I doubt we'll have a reason to change this... Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: fix long lines in block/blk-iopoll.cJens Axboe2009-09-11
| | | | | | | Note sure why they happened in the first place, probably some bad terminal setting. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: add blk-iopoll, a NAPI like approach for block devicesJens Axboe2009-09-11
This borrows some code from NAPI and implements a polled completion mode for block devices. The idea is the same as NAPI - instead of doing the command completion when the irq occurs, schedule a dedicated softirq in the hopes that we will complete more IO when the iopoll handler is invoked. Devices have a budget of commands assigned, and will stay in polled mode as long as they continue to consume their budget from the iopoll softirq handler. If they do not, the device is set back to interrupt completion mode. This patch holds the core bits for blk-iopoll, device driver support sold separately. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>