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* padata: ensure padata_do_serial() runs on the correct CPUMathias Krause2017-10-071-1/+19
| | | | | | | | | | | | | | | | If the algorithm we're parallelizing is asynchronous we might change CPUs between padata_do_parallel() and padata_do_serial(). However, we don't expect this to happen as we need to enqueue the padata object into the per-cpu reorder queue we took it from, i.e. the same-cpu's parallel queue. Ensure we're not switching CPUs for a given padata object by tracking the CPU within the padata object. If the serial callback gets called on the wrong CPU, defer invoking padata_reorder() via a kernel worker on the CPU we're expected to run on. Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: ensure the reorder timer callback runs on the correct CPUMathias Krause2017-10-071-1/+42
| | | | | | | | | | | | | | | The reorder timer function runs on the CPU where the timer interrupt was handled which is not necessarily one of the CPUs of the 'pcpu' CPU mask set. Ensure the padata_reorder() callback runs on the correct CPU, which is one in the 'pcpu' CPU mask set and, preferrably, the next expected one. Do so by comparing the current CPU with the expected target CPU. If they match, call padata_reorder() right away. If they differ, schedule a work item on the target CPU that does the padata_reorder() call for us. Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: set cpu_index of unused CPUs to -1Mathias Krause2017-10-071-1/+7
| | | | | | | | | | | | | | | The parallel queue per-cpu data structure gets initialized only for CPUs in the 'pcpu' CPU mask set. This is not sufficient as the reorder timer may run on a different CPU and might wrongly decide it's the target CPU for the next reorder item as per-cpu memory gets memset(0) and we might be waiting for the first CPU in cpumask.pcpu, i.e. cpu_index 0. Make the '__this_cpu_read(pd->pqueue->cpu_index) == next_queue->cpu_index' compare in padata_get_next() fail in this case by initializing the cpu_index member of all per-cpu parallel queues. Use -1 for unused ones. Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: Avoid nested calls to cpus_read_lock() in pcrypt_init_padata()Sebastian Andrzej Siewior2017-05-261-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | pcrypt_init_padata() cpus_read_lock() padata_alloc_possible() padata_alloc() cpus_read_lock() The nested call to cpus_read_lock() works with the current implementation, but prevents the conversion to a percpu rwsem. The other caller of padata_alloc_possible() is pcrypt_init_padata() which calls from a cpus_read_lock() protected region as well. Remove the cpus_read_lock() call in padata_alloc() and document the calling convention. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-crypto@vger.kernel.org Link: http://lkml.kernel.org/r/20170524081547.571278910@linutronix.de
* padata: Make padata_alloc() staticThomas Gleixner2017-05-261-16/+16
| | | | | | | | | | | | | | | No users outside of padata.c Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-crypto@vger.kernel.org Link: http://lkml.kernel.org/r/20170524081547.491457256@linutronix.de
* padata: get_next is never NULLJason A. Donenfeld2017-04-211-9/+4
| | | | | | | | | | | Per Dan's static checker warning, the code that returns NULL was removed in 2010, so this patch updates the comments and fixes the code assumptions. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: free correct variableJason A. Donenfeld2017-04-101-1/+1
| | | | | | | | | | The author meant to free the variable that was just allocated, instead of the one that failed to be allocated, but made a simple typo. This patch rectifies that. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: avoid race in reorderingJason A. Donenfeld2017-03-241-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Under extremely heavy uses of padata, crashes occur, and with list debugging turned on, this happens instead: [87487.298728] WARNING: CPU: 1 PID: 882 at lib/list_debug.c:33 __list_add+0xae/0x130 [87487.301868] list_add corruption. prev->next should be next (ffffb17abfc043d0), but was ffff8dba70872c80. (prev=ffff8dba70872b00). [87487.339011] [<ffffffff9a53d075>] dump_stack+0x68/0xa3 [87487.342198] [<ffffffff99e119a1>] ? console_unlock+0x281/0x6d0 [87487.345364] [<ffffffff99d6b91f>] __warn+0xff/0x140 [87487.348513] [<ffffffff99d6b9aa>] warn_slowpath_fmt+0x4a/0x50 [87487.351659] [<ffffffff9a58b5de>] __list_add+0xae/0x130 [87487.354772] [<ffffffff9add5094>] ? _raw_spin_lock+0x64/0x70 [87487.357915] [<ffffffff99eefd66>] padata_reorder+0x1e6/0x420 [87487.361084] [<ffffffff99ef0055>] padata_do_serial+0xa5/0x120 padata_reorder calls list_add_tail with the list to which its adding locked, which seems correct: spin_lock(&squeue->serial.lock); list_add_tail(&padata->list, &squeue->serial.list); spin_unlock(&squeue->serial.lock); This therefore leaves only place where such inconsistency could occur: if padata->list is added at the same time on two different threads. This pdata pointer comes from the function call to padata_get_next(pd), which has in it the following block: next_queue = per_cpu_ptr(pd->pqueue, cpu); padata = NULL; reorder = &next_queue->reorder; if (!list_empty(&reorder->list)) { padata = list_entry(reorder->list.next, struct padata_priv, list); spin_lock(&reorder->lock); list_del_init(&padata->list); atomic_dec(&pd->reorder_objects); spin_unlock(&reorder->lock); pd->processed++; goto out; } out: return padata; I strongly suspect that the problem here is that two threads can race on reorder list. Even though the deletion is locked, call to list_entry is not locked, which means it's feasible that two threads pick up the same padata object and subsequently call list_add_tail on them at the same time. The fix is thus be hoist that lock outside of that block. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: Remove unused but set variablesTobias Klauser2016-10-251-4/+0
| | | | | | | | | | | | | | Remove the unused but set variable pinst in padata_parallel_worker to fix the following warning when building with 'W=1': kernel/padata.c: In function ‘padata_parallel_worker’: kernel/padata.c:68:26: warning: variable ‘pinst’ set but not used [-Wunused-but-set-variable] Also remove the now unused variable pd which is only used to set pinst. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: Convert to hotplug state machineSebastian Andrzej Siewior2016-09-191-38/+50
| | | | | | | | | | | | | | | | Install the callbacks via the state machine. CPU-hotplug multinstance support is used with the nocalls() version. Maybe parts of padata_alloc() could be moved into the online callback so that we could invoke ->startup callback for instance and drop get_online_cpus(). Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-crypto@vger.kernel.org Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160906170457.32393-14-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* kernel/padata.c: hide unused functionsArnd Bergmann2016-05-191-37/+37
| | | | | | | | | | | | | | | | | | | | | | | | | A recent cleanup removed some exported functions that were not used anywhere, which in turn exposed the fact that some other functions in the same file are only used in some configurations. We now get a warning about them when CONFIG_HOTPLUG_CPU is disabled: kernel/padata.c:670:12: error: '__padata_remove_cpu' defined but not used [-Werror=unused-function] static int __padata_remove_cpu(struct padata_instance *pinst, int cpu) ^~~~~~~~~~~~~~~~~~~ kernel/padata.c:650:12: error: '__padata_add_cpu' defined but not used [-Werror=unused-function] static int __padata_add_cpu(struct padata_instance *pinst, int cpu) This rearranges the code so the __padata_remove_cpu/__padata_add_cpu functions are within the #ifdef that protects the code that calls them. [akpm@linux-foundation.org: coding-style fixes] Fixes: 4ba6d78c671e ("kernel/padata.c: removed unused code") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Richard Cochran <rcochran@linutronix.de> Cc: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel/padata.c: removed unused codeRichard Cochran2016-05-191-64/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | By accident I stumbled across code that has never been used. This driver has EXPORT_SYMBOL functions, and the only user of the code is pcrypt.c, but this only uses a subset of the exported symbols. According to 'git log -G', the functions, padata_set_cpumasks, padata_add_cpu, and padata_remove_cpu have never been used since they were first introduced. This patch removes the unused code. On one 64 bit build, with CRYPTO_PCRYPT built in, the text is more than 4k smaller. kbuild_hp> size $KBUILD_OUTPUT/vmlinux text data bss dec hex filename 10566658 4678360 1122304 16367322 f9beda vmlinux 10561984 4678360 1122304 16362648 f9ac98 vmlinux On another config, 32 bit, the saving is about 0.5k bytes. kbuild_hp-x86> size $KBUILD_OUTPUT/vmlinux 6012005 2409513 2785280 11206798 ab008e vmlinux 6011491 2409513 2785280 11206284 aafe8c vmlinux Signed-off-by: Richard Cochran <rcochran@linutronix.de> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* padata: use %*pb[l] to print bitmaps including cpumasks and nodemasksTejun Heo2015-02-131-8/+3
| | | | | | | | | | | | printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* padata: Fix wrong usage of rcu_dereference()Mathias Krause2013-12-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | A kernel with enabled lockdep complains about the wrong usage of rcu_dereference() under a rcu_read_lock_bh() protected region. =============================== [ INFO: suspicious RCU usage. ] 3.13.0-rc1+ #126 Not tainted ------------------------------- linux/kernel/padata.c:115 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 1 1 lock held by cryptomgr_test/153: #0: (rcu_read_lock_bh){.+....}, at: [<ffffffff8115c235>] padata_do_parallel+0x5/0x270 Fix that by using rcu_dereference_bh() instead. Signed-off-by: Mathias Krause <minipli@googlemail.com> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: make the sequence counter an atomic_tMathias Krause2013-10-301-5/+4
| | | | | | | | | | | | | | | | | | | | Using a spinlock to atomically increase a counter sounds wrong -- we've atomic_t for this! Also move 'seq_nr' to a different cache line than 'lock' to reduce cache line trashing. This has the nice side effect of decreasing the size of struct parallel_data from 192 to 128 bytes for a x86-64 build, e.g. occupying only two instead of three cache lines. Those changes results in a 5% performance increase on an IPsec test run using pcrypt. Btw. the seq_lock spinlock was never explicitly initialized -- one more reason to get rid of it. Signed-off-by: Mathias Krause <mathias.krause@secunet.com> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata - Register hotcpu notifier after initializationRichard Weinberger2013-08-291-6/+6
| | | | | | | | | | padata_cpu_callback() takes pinst->lock, to avoid taking an uninitialized lock, register the notifier after it's initialization. Signed-off-by: Richard Weinberger <richard@nod.at> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata - share code between CPU_ONLINE and CPU_DOWN_FAILED, same to ↵Chen Gang2013-08-291-16/+4
| | | | | | | | | | | | | | | | CPU_DOWN_PREPARE and CPU_UP_CANCELED Share code between CPU_ONLINE and CPU_DOWN_FAILED, same to CPU_DOWN_PREPARE and CPU_UP_CANCELED. It will fix 2 bugs: "not check the return value of __padata_remove_cpu() and __padata_add_cpu()". "need add 'break' between CPU_UP_CANCELED and CPU_DOWN_FAILED". Signed-off-by: Chen Gang <gang.chen@asianux.com> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: use __this_cpu_read per-cpu helperShan Wei2012-12-061-3/+2
| | | | | | | | | For bottom halves off, __this_cpu_read is better. Signed-off-by: Shan Wei <davidshan@tencent.com> Reviewed-by: Christoph Lameter <cl@linux.com> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: Fix cpu hotplugSteffen Klassert2012-03-291-0/+3
| | | | | | | | | | We don't remove the cpu that went offline from our cpumasks on cpu hotplug. This got lost somewhere along the line, so restore it. This fixes a hang of the padata instance on cpu hotplug. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: Use the online cpumask as the defaultSteffen Klassert2012-03-291-4/+4
| | | | | | | | | | | | We use the active cpumask to determine the superset of cpus to use for parallelization. However, the active cpumask is for internal usage of the scheduler and therefore not the appropriate cpumask for these purposes. So use the online cpumask instead. Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: Add a reference to the api documentationSteffen Klassert2012-03-291-0/+2
| | | | | | | | Add a reference to the padata api documentation at Documentation/padata.txt Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: Fix race on sequence number wrapSteffen Klassert2012-03-141-28/+10
| | | | | | | | | | | | | | | When padata_do_parallel() is called from multiple cpus for the same padata instance, we can get object reordering on sequence number wrap because testing for sequence number wrap and reseting the sequence number must happen atomically but is implemented with two atomic operations. This patch fixes this by converting the sequence number from atomic_t to an unsigned int and protect the access with a spin_lock. As a side effect, we get rid of the sequence number wrap handling because the seqence number wraps back to null now without the need to do anything. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: Fix race in the serialization pathSteffen Klassert2012-03-141-2/+4
| | | | | | | | | When a padata object is queued to the serialization queue, another cpu might process and free the padata object. So don't dereference it after queueing to the serialization queue. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* kernel: Map most files to use export.h instead of module.hPaul Gortmaker2011-10-311-1/+1
| | | | | | | | | | | | | | | | The changed files were only including linux/module.h for the EXPORT_SYMBOL infrastructure, and nothing else. Revector them onto the isolated export header for faster compile times. Nothing to see here but a whole lot of instances of: -#include <linux/module.h> +#include <linux/export.h> This commit is only changing the kernel dir; next targets will probably be mm, fs, the arch dirs, etc. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* Fix common misspellingsLucas De Marchi2011-03-311-4/+4
| | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Linus Torvalds2010-08-041-197/+558
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (39 commits) random: Reorder struct entropy_store to remove padding on 64bits padata: update API documentation padata: Remove padata_get_cpumask crypto: pcrypt - Update pcrypt cpumask according to the padata cpumask notifier crypto: pcrypt - Rename pcrypt_instance padata: Pass the padata cpumasks to the cpumask_change_notifier chain padata: Rearrange set_cpumask functions padata: Rename padata_alloc functions crypto: pcrypt - Dont calulate a callback cpu on empty callback cpumask padata: Check for valid cpumasks padata: Allocate cpumask dependend recources in any case padata: Fix cpu index counting crypto: geode_aes - Convert pci_table entries to PCI_VDEVICE (if PCI_ANY_ID is used) pcrypt: Added sysfs interface to pcrypt padata: Added sysfs primitives to padata subsystem padata: Make two separate cpumasks padata: update documentation padata: simplify serialization mechanism padata: make padata_do_parallel to return zero on success padata: Handle empty padata cpumasks ...
| * padata: Remove padata_get_cpumaskSteffen Klassert2010-07-311-35/+0
| | | | | | | | | | | | | | | | | | | | | | | | A function that copies the padata cpumasks to a user buffer is a bit error prone. The cpumask can change any time so we can't be sure to have the right cpumask when using this function. A user who is interested in the padata cpumasks should register to the padata cpumask notifier chain instead. Users of padata_get_cpumask are already updated, so we can remove it. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| * padata: Pass the padata cpumasks to the cpumask_change_notifier chainSteffen Klassert2010-07-311-1/+2
| | | | | | | | | | | | | | | | | | We pass a pointer to the new padata cpumasks to the cpumask_change_notifier chain. So users can access the cpumasks without the need of an extra padata_get_cpumask function. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| * padata: Rearrange set_cpumask functionsSteffen Klassert2010-07-311-50/+67
| | | | | | | | | | | | | | | | | | | | padata_set_cpumask needs to be protected by a lock. We make __padata_set_cpumasks unlocked and static. So this function can be used by the exported and locked padata_set_cpumask and padata_set_cpumasks functions. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| * padata: Rename padata_alloc functionsSteffen Klassert2010-07-311-12/+12
| | | | | | | | | | | | | | | | | | | | | | | | We rename padata_alloc to padata_alloc_possible because this function allocates a padata_instance and uses the cpu_possible mask for parallel and serial workers. Also we rename __padata_alloc to padata_alloc to avoid to export underlined functions. Underlined functions are considered to be private to padata. Users are updated accordingly. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| * padata: Check for valid cpumasksSteffen Klassert2010-07-261-1/+1
| | | | | | | | | | | | | | | | | | | | Now that we allow to change the cpumasks from userspace, we have to check for valid cpumasks in padata_do_parallel. This patch adds the necessary check. This fixes a division by zero crash if the parallel cpumask contains no active cpu. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| * padata: Allocate cpumask dependend recources in any caseSteffen Klassert2010-07-261-17/+7
| | | | | | | | | | | | | | | | | | | | | | The cpumask separation work assumes the cpumask dependend recources present regardless of valid or invalid cpumasks. With this patch we allocate the cpumask dependend recources in any case. This fixes two NULL pointer dereference crashes in padata_replace and in padata_get_cpumask. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| * padata: Fix cpu index countingSteffen Klassert2010-07-261-0/+1
| | | | | | | | | | | | | | | | | | The counting of the cpu index got lost with a recent commit. This patch restores it. This fixes a hang of the parallel worker threads on cpu hotplug. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| * padata: Added sysfs primitives to padata subsystemDan Kruchinin2010-07-191-9/+146
| | | | | | | | | | | | | | | | | | | | | | | | Added sysfs primitives to padata subsystem. Now API user may embedded kobject each padata instance contains into any sysfs hierarchy. For now padata sysfs interface provides only two objects: serial_cpumask [RW] - cpumask for serial workers parallel_cpumask [RW] - cpumask for parallel workers Signed-off-by: Dan Kruchinin <dkruchinin@acm.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| * padata: Make two separate cpumasksDan Kruchinin2010-07-191-124/+347
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The aim of this patch is to make two separate cpumasks for padata parallel and serial workers respectively. It allows user to make more thin and sophisticated configurations of padata framework. For example user may bind parallel and serial workers to non-intersecting CPU groups to gain better performance. Also each padata instance has notifiers chain for its cpumasks now. If either parallel or serial or both masks were changed all interested subsystems will get notification about that. It's especially useful if padata user uses algorithm for callback CPU selection according to serial cpumask. Signed-off-by: Dan Kruchinin <dkruchinin@acm.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| * padata: simplify serialization mechanismSteffen Klassert2010-07-141-52/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | We count the number of processed objects on a percpu basis, so we need to go through all the percpu reorder queues to calculate the sequence number of the next object that needs serialization. This patch changes this to count the number of processed objects global. So we can calculate the sequence number and the percpu reorder queue of the next object that needs serialization without searching through the percpu reorder queues. This avoids some accesses to memory of foreign cpus. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| * padata: make padata_do_parallel to return zero on successSteffen Klassert2010-07-141-6/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | To return -EINPROGRESS on success in padata_do_parallel was considered to be odd. This patch changes this to return zero on success. Also the only user of padata, pcrypt is adapted to convert a return of zero to -EINPROGRESS within the crypto layer. This also removes the pcrypt fallback if padata_do_parallel was called on a not running padata instance as we can't handle it anymore. This fallback was unused, so it's save to remove it. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| * padata: Handle empty padata cpumasksSteffen Klassert2010-07-141-11/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes a bug when the padata cpumask does not intersect with the active cpumask. In this case we get a division by zero in padata_alloc_pd and we end up with a useless padata instance. Padata can end up with an empty cpumask for two reasons: 1. A user removed the last cpu that belongs to the padata cpumask and the active cpumask. 2. The last cpu that belongs to the padata cpumask and the active cpumask goes offline. We introduce a function padata_validate_cpumask to check if the padata cpumask does intersect with the active cpumask. If the cpumasks do not intersect we mark the instance as invalid, so it can't be used. We do not allocate the cpumask dependend recources in this case. This fixes the division by zero and keeps the padate instance in a consistent state. It's not possible to trigger this bug by now because the only padata user, pcrypt uses always the possible cpumask. Reported-by: Dan Kruchinin <dkruchinin@acm.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| * padata: Block until the instance is unused on stopSteffen Klassert2010-07-141-8/+16
| | | | | | | | | | | | | | | | | | | | This patch makes padata_stop to block until the padata instance is unused. Also we split padata_stop to a locked and a unlocked version. This is in preparation to be able to change the cpumask after a call to patata stop. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| * padata: Check for valid padata instance on startSteffen Klassert2010-07-141-2/+16
| | | | | | | | | | | | | | | | | | | | | | | | This patch introduces the PADATA_INVALID flag which is checked on padata start. This will be used to mark a padata instance as invalid, if the padata cpumask does not intersect with the active cpumask. we change padata_start to return an error if the PADATA_INVALID is set. Also we adapt the only padata user, pcrypt to this change. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| * padata: add parenthesis in MAX_SEQ_NR macroDan Carpenter2010-06-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | MAX_SEQ_NR is used in padata_alloc_pd() like this: pd->max_seq_nr = (MAX_SEQ_NR / num_cpus) * num_cpus - 1; It needs parenthesis or the divide by num_cpus takes precedence over the subtraction. Signed-off-by: Dan Carpenter <error27@gmail.com> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* | kernel/: convert cpu notifier to return encapsulate errno valueAkinobu Mita2010-05-271-2/+2
|/ | | | | | | | | | | By the previous modification, the cpu notifier can return encapsulate errno value. This converts the cpu notifiers for kernel/*.c Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* padata: Use get_online_cpus/put_online_cpus in padata_freeSteffen Klassert2010-05-191-0/+3
| | | | | | | | Add get_online_cpus/put_online_cpus to ensure that no cpu goes offline during the flushing of the padata percpu queues. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: Add some code commentsSteffen Klassert2010-05-191-11/+57
| | | | | Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: Flush the padata queues activelySteffen Klassert2010-05-191-8/+25
| | | | | | | | | | yield was used to wait until all references of the internal control structure in use are dropped before it is freed. This patch implements padata_flush_queues which actively flushes the padata percpu queues in this case. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: Use a timer to handle remaining objects in the reorder queues Steffen Klassert2010-05-191-7/+18
| | | | | | | | | | | | | | | | | | | | | | | padata_get_next needs to check whether the next object that need serialization must be parallel processed by the local cpu. This check was wrong implemented and returned always true, so the try_again loop in padata_reorder was never taken. This can lead to object leaks in some rare cases due to a race that appears with the trylock in padata_reorder. The try_again loop was not a good idea after all, because a cpu could take that loop frequently, so we handle this with a timer instead. This patch adds a timer to handle the race that appears with the trylock. If cpu1 queues an object to the reorder queue while cpu2 holds the pd->lock but left the while loop in padata_reorder already, cpu2 can't care for this object and cpu1 exits because it can't get the lock. Usually the next cpu that takes the lock cares for this object too. We need the timer just if this object was the last one that arrives to the reorder queues. The timer function sends it out in this case. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: Use get_online_cpus/put_online_cpusSteffen Klassert2010-05-031-0/+13
| | | | | | | | | This patch puts get_online_cpus/put_online_cpus around the places we modify the padata cpumask to ensure that no cpu goes offline during this operation. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: Initialize the padata queues only for the used cpusSteffen Klassert2010-05-031-9/+5
| | | | | | | | | padata_alloc_pd set up queues for all possible cpus. This patch changes this to set up the queues just for the used cpus. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: Remove superfluous might_sleepSteffen Klassert2010-05-031-10/+0
| | | | | | | | might_sleep() was placed before mutex_lock() in some places. We remove them because mutex_lock() does might_sleep() too. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* padata: cpu hotplug code should depend on CONFIG_HOTPLUG_CPUSteffen Klassert2010-05-031-6/+7
| | | | | | | This patch makes the padata cpu hotplug code dependend on CONFIG_HOTPLUG_CPU. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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