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2015-04-16cpumask: resurrect CPU_MASK_CPU0Rusty Russell1-0/+5
We removed it in 2f0f267ea072 (cpumask: remove deprecated functions.), but grep shows it still used by MIPS, and not unreasonably. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-03-31linux/cpumask.h: add typechecking to cpumask_test_cpuRasmus Villemoes1-4/+4
The Subtlety (1) referred to vanished with 6ba2ef7baac2 ("cpumask: Move deprecated functions to end of header."). That used to mention some suboptimal code generation by a, by now, rather ancient gcc. With gcc 4.7, I don't see any change in the generated code by making it a static inline, so let's add type checking and get rid of the ghost reference. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-03-10cpumask: only allocate nr_cpumask_bits.Rusty Russell1-3/+2
Now we'll find out the hard way if anyone has CPUMASK_OFFSTACK and is returning these or assigning them. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-03-10cpumask: remove deprecated functions.Rusty Russell1-151/+0
Using these functions with offstack cpus is unsafe. They use all NR_CPUS bits, unstead of nr_cpumask_bits. In particular, lustre (in staging) used cpus_ and that caused a bug. Reported-by: Oleg Drokin <green@linuxhacker.ru> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-03-05CPU_MASK_ALL/CPU_MASK_NONE: remove from deprecated region.Rusty Russell1-19/+12
They're used to initialize various static fields, though static cpumasks should generally be avoided. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-02-13bitmap, cpumask, nodemask: remove dedicated formatting functionsTejun Heo1-31/+0
Now that all bitmap formatting usages have been converted to '%*pb[l]', the separate formatting functions are unnecessary. The following functions are removed. * bitmap_scn[list]printf() * cpumask_scnprintf(), cpulist_scnprintf() * [__]nodemask_scnprintf(), [__]nodelist_scnprintf() * seq_bitmap[_list](), seq_cpumask[_list](), seq_nodemask[_list]() * seq_buf_bitmask() Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13cpumask, nodemask: implement cpumask/nodemask_pr_args()Tejun Heo1-0/+8
printf family of functions can now format bitmaps using '%*pb[l]' and all cpumask and nodemask formatting will be converted to use it. To ease printing these masks with '%*pb[l]' which require two params - the number of bits and the actual bitmap, this patch implement cpumask_pr_args() and nodemask_pr_args() which can be used to provide arguments for '%*pb[l]' Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "David S. Miller" <davem@davemloft.net> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: "John W. Linville" <linville@tuxdriver.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Chris Zankel <chris@zankel.net> Cc: Christoph Lameter <cl@linux.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Mike Travis <travis@sgi.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13cpumask: always use nr_cpu_ids in formatting and parsing functionsTejun Heo1-7/+7
bitmap implements two variants of scnprintf functions to format a bitmap into a string and cpumask and nodemask wrap them to provide equivalent interfaces. The scnprintf family of functions require a string buffer as an output target which complicates code paths which just want to print out the mask through printk for informational or debug purposes as they have to worry about how large the buffer should be and whether it's too large to allocate on stack. Neither cpumask or nodemask provides a guildeline on how large the target buffer should be forcing users come up with their own solutions - some allocate an arbitrarily sized buffer which is small enough to allocate on stack but may be too short in corner cases, other come up with a custom upper limit calculation considering the output format, some allocate the buffer dynamically while one resorted to using lock to synchronize access to a static buffer. This is an artificial problem which is being solved repeatedly for no benefit. In a lot of cases, the output area already exists and can be targeted directly making the intermediate buffer unnecessary. This patchset teaches printf family of functions how to format bitmaps and replace the dedicated formatting functions with it. Pointer formatting is extended to cover bitmap formatting. It uses the field width for the number of bits instead of precision. The format used is '%*pb[l]', with the optional trailing 'l' specifying list format instead of hex masks. For more details, please see 0002. This patch (of 31): Currently, the formatting and parsing functions in cpumask.h use nr_cpumask_bits like other cpumask functions; however, nr_cpumask_bits is either NR_CPUS or nr_cpu_ids depending on CONFIG_CPUMASK_OFFSTACK. This leads to inconsistent behaviors. With CONFIG_NR_CPUS=512 and !CONFIG_CPUMASK_OFFSTACK # cat /sys/devices/virtual/net/lo/queues/rx-0/rps_cpus 00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000 # cat /proc/self/status | grep Cpus_allowed: Cpus_allowed: f With CONFIG_NR_CPUS=1024 and CONFIG_CPUMASK_OFFSTACK (fedora default) # cat /sys/devices/virtual/net/lo/queues/rx-0/rps_cpus 0 # cat /proc/self/status | grep Cpus_allowed: Cpus_allowed: f Note that /proc/self/status is always using nr_cpu_ids regardless of config. This is because seq cpumask formattings functions always use nr_cpu_ids. Given that the same output fields may switch between the two forms, converging on nr_cpu_ids always isn't too likely to surprise userland. This patch updates the formatting and parsing functions in cpumask.h to always use nr_cpu_ids. There's no point in dealing with CPUs which aren't even possible on the machine. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: "John W. Linville" <linville@tuxdriver.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Chris Zankel <chris@zankel.net> Cc: Christoph Lameter <cl@linux.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Mike Travis <travis@sgi.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12linux/cpumask.h: update bitmap wrappers to take unsigned intRasmus Villemoes1-11/+11
Since the various bitmap_* functions now take an unsigned int as nbits parameter, it makes sense to also update the various wrappers, even though they're marked as obsolete. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-11-07cpumask: factor out show_cpumap into separate helper functionSudeep Holla1-0/+17
Many sysfs *_show function use cpu{list,mask}_scnprintf to copy cpumap to the buffer aligned to PAGE_SIZE, append '\n' and '\0' to return null terminated buffer with newline. This patch creates a new helper function cpumap_print_to_pagebuf in cpumask.h using newly added bitmap_print_to_pagebuf and consolidates most of those sysfs functions using the new helper function. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Suggested-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: "Rafael J. Wysocki" <rjw@rjwysocki.net> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: x86@kernel.org Cc: linux-acpi@vger.kernel.org Cc: linux-pci@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-08-28percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_tChristoph Lameter1-0/+11
__get_cpu_var can paper over differences in the definitions of cpumask_var_t and either use the address of the cpumask variable directly or perform a fetch of the address of the struct cpumask allocated elsewhere. This is important particularly when using per cpu cpumask_var_t declarations because in one case we have an offset into a per cpu area to handle and in the other case we need to fetch a pointer from the offset. This patch introduces a new macro this_cpu_cpumask_var_ptr() that is defined where cpumask_var_t is defined and performs the proper actions. All use cases where __get_cpu_var is used with cpumask_var_t are converted to the use of this_cpu_cpumask_var_ptr(). Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2014-06-12Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds1-0/+8
Pull networking updates from David Miller: 1) Seccomp BPF filters can now be JIT'd, from Alexei Starovoitov. 2) Multiqueue support in xen-netback and xen-netfront, from Andrew J Benniston. 3) Allow tweaking of aggregation settings in cdc_ncm driver, from Bjørn Mork. 4) BPF now has a "random" opcode, from Chema Gonzalez. 5) Add more BPF documentation and improve test framework, from Daniel Borkmann. 6) Support TCP fastopen over ipv6, from Daniel Lee. 7) Add software TSO helper functions and use them to support software TSO in mvneta and mv643xx_eth drivers. From Ezequiel Garcia. 8) Support software TSO in fec driver too, from Nimrod Andy. 9) Add Broadcom SYSTEMPORT driver, from Florian Fainelli. 10) Handle broadcasts more gracefully over macvlan when there are large numbers of interfaces configured, from Herbert Xu. 11) Allow more control over fwmark used for non-socket based responses, from Lorenzo Colitti. 12) Do TCP congestion window limiting based upon measurements, from Neal Cardwell. 13) Support busy polling in SCTP, from Neal Horman. 14) Allow RSS key to be configured via ethtool, from Venkata Duvvuru. 15) Bridge promisc mode handling improvements from Vlad Yasevich. 16) Don't use inetpeer entries to implement ID generation any more, it performs poorly, from Eric Dumazet. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1522 commits) rtnetlink: fix userspace API breakage for iproute2 < v3.9.0 tcp: fixing TLP's FIN recovery net: fec: Add software TSO support net: fec: Add Scatter/gather support net: fec: Increase buffer descriptor entry number net: fec: Factorize feature setting net: fec: Enable IP header hardware checksum net: fec: Factorize the .xmit transmit function bridge: fix compile error when compiling without IPv6 support bridge: fix smatch warning / potential null pointer dereference via-rhine: fix full-duplex with autoneg disable bnx2x: Enlarge the dorq threshold for VFs bnx2x: Check for UNDI in uncommon branch bnx2x: Fix 1G-baseT link bnx2x: Fix link for KR with swapped polarity lane sctp: Fix sk_ack_backlog wrap-around problem net/core: Add VF link state control policy net/fsl: xgmac_mdio is dependent on OF_MDIO net/fsl: Make xgmac_mdio read error message useful net_sched: drr: warn when qdisc is not work conserving ...
2014-06-11cpumask: Utility function to set n'th cpu - local cpu firstAmir Vadai1-0/+8
This function sets the n'th cpu - local cpu's first. For example: in a 16 cores server with even cpu's local, will get the following values: cpumask_set_cpu_local_first(0, numa, cpumask) => cpu 0 is set cpumask_set_cpu_local_first(1, numa, cpumask) => cpu 2 is set ... cpumask_set_cpu_local_first(7, numa, cpumask) => cpu 14 is set cpumask_set_cpu_local_first(8, numa, cpumask) => cpu 1 is set cpumask_set_cpu_local_first(9, numa, cpumask) => cpu 3 is set ... cpumask_set_cpu_local_first(15, numa, cpumask) => cpu 15 is set Curently this function will be used by multi queue networking devices to calculate the irq affinity mask, such that as many local cpu's as possible will be utilized to handle the mq device irq's. Signed-off-by: Amir Vadai <amirv@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-01net: Revert mlx4 cpumask changes.David S. Miller1-2/+0
This reverts commit 70a640d0dae3a9b1b222ce673eb5d92c263ddd61 ("net/mlx4_en: Use affinity hint") and commit c8865b64b05b2f4eeefd369373e9c8aeb069e7a1 ("cpumask: Utility function to set n'th cpu - local cpu first") because these changes break the build when SMP is disabled amongst other things. Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-01cpumask: Utility function to set n'th cpu - local cpu firstAmir Vadai1-0/+2
This function sets the n'th cpu - local cpu's first. For example: in a 16 cores server with even cpu's local, will get the following values: cpumask_set_cpu_local_first(0, numa, cpumask) => cpu 0 is set cpumask_set_cpu_local_first(1, numa, cpumask) => cpu 2 is set ... cpumask_set_cpu_local_first(7, numa, cpumask) => cpu 14 is set cpumask_set_cpu_local_first(8, numa, cpumask) => cpu 1 is set cpumask_set_cpu_local_first(9, numa, cpumask) => cpu 3 is set ... cpumask_set_cpu_local_first(15, numa, cpumask) => cpu 15 is set Curently this function will be used by multi queue networking devices to calculate the irq affinity mask, such that as many local cpu's as possible will be utilized to handle the mq device irq's. Signed-off-by: Amir Vadai <amirv@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-14cpumask.h: silence warning with -Wsign-compareBrian W Hart1-1/+1
Silence the warning when building with -Wsign-compare when cpumask.h is included: include/linux/cpumask.h: In function ‘cpumask_parse’: include/linux/cpumask.h:603:26: warning: signed and unsigned type in conditional expression [-Wsign-compare] int len = nl ? nl - buf : strlen(buf); ^ V2: Rusty pointed out that unsigned should be used instead. Signed-off-by: Brian W Hart <hartb@linux.vnet.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-03-12cpumask: implement cpumask_parse()Tejun Heo1-0/+15
We have cpulist_parse() but not cpumask_parse(). Implement it using bitmap_parse(). bitmap_parse() is weird in that it takes @len for a string in kernel-memory which also is inconsistent with bitmap_parselist(). Make cpumask_parse() calculate the length and don't expose the inconsistency to cpumask users. Maybe we can fix up bitmap_parse() later. This will be used to expose workqueue cpumask knobs to userland via sysfs. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au>
2012-07-27cpumask: cpulist_parse() comments correctionAlex Shi1-2/+1
As introduced in Rusty's commit 29c0177e6a4, the function has no parameter @len, so need to remove it from comments to avoid kernel-doc warning: alexs@debian:~/linux-next$ scripts/kernel-doc -man include/linux/cpumask.h | split-man.pl /tmp/man .... Warning(include/linux/cpumask.h:602): Excess function parameter 'len' description in 'cpulist_parse' and correct the function name in comments to cpulist_parse. Signed-off-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-07-27cpumask: add a few comments of cpumask functionsAlex Shi1-0/+12
Current few cpumask functions' purposes are not quite clear. Stupid user like myself needs to dig into details for clear function purpose and return value. Add few explanation for them is helpful. Thanks for Srivatsa's comments and correction! Signed-off-by: Alex Shi <alex.shi@intel.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-03-29cpumask: remove old cpu_*_map.Rusty Russell1-6/+0
These are obsolete: cpu_*_mask provides (const) pointers. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-03-28lib/cpumask.c: remove __any_online_cpu()Srivatsa S. Bhat1-2/+1
__any_online_cpu() is not optimal and also unnecessary. So, replace its use by faster cpumask_* operations. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Venkatesh Pallipadi <venki@google.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-04BUG: headers with BUG/BUG_ON etc. need linux/bug.hPaul Gortmaker1-0/+1
If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any other BUG variant in a static inline (i.e. not in a #define) then that header really should be including <linux/bug.h> and not just expecting it to be implicitly present. We can make this change risk-free, since if the files using these headers didn't have exposure to linux/bug.h already, they would have been causing compile failures/warnings. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-07-26cpumask: add cpumask_var_t documentationKOSAKI Motohiro1-0/+14
cpumask_var_t has one notable difference from cpumask_t. Add the explanation. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Thiago Farina <tfransosi@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25bitmap, irq: add smp_affinity_list interface to /proc/irqMike Travis1-0/+15
Manually adjusting the smp_affinity for IRQ's becomes unwieldy when the cpu count is large. Setting smp affinity to cpus 256 to 263 would be: echo 000000ff,00000000,00000000,00000000,00000000,00000000,00000000,00000000 > smp_affinity instead of: echo 256-263 > smp_affinity_list Think about what it looks like for cpus around say, 4088 to 4095. We already have many alternate "list" interfaces: /sys/devices/system/cpu/cpuX/indexY/shared_cpu_list /sys/devices/system/cpu/cpuX/topology/thread_siblings_list /sys/devices/system/cpu/cpuX/topology/core_siblings_list /sys/devices/system/node/nodeX/cpulist /sys/devices/pci***/***/local_cpulist Add a companion interface, smp_affinity_list to use cpu lists instead of cpu maps. This conforms to other companion interfaces where both a map and a list interface exists. This required adding a bitmap_parselist_user() function in a manner similar to the bitmap_parse_user() function. [akpm@linux-foundation.org: make __bitmap_parselist() static] Signed-off-by: Mike Travis <travis@sgi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jack Steiner <steiner@sgi.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06cpumask: let num_*_cpus() function always return unsigned valuesHeiko Carstens1-4/+4
Dependent on CONFIG_SMP the num_*_cpus() functions return unsigned or signed values. Let them always return unsigned values to avoid strange casts. Fixes at least one warning: kernel/kprobes.c: In function 'register_kretprobe': kernel/kprobes.c:1038: warning: comparison of distinct pointer types lacks a cast Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-02-25rcu: Accelerate grace period if last non-dynticked CPUPaul E. McKenney1-0/+14
Currently, rcu_needs_cpu() simply checks whether the current CPU has an outstanding RCU callback, which means that the last CPU to go into dyntick-idle mode might wait a few ticks for the relevant grace periods to complete. However, if all the other CPUs are in dyntick-idle mode, and if this CPU is in a quiescent state (which it is for RCU-bh and RCU-sched any time that we are considering going into dyntick-idle mode), then the grace period is instantly complete. This patch therefore repeatedly invokes the RCU grace-period machinery in order to force any needed grace periods to complete quickly. It does so a limited number of times in order to prevent starvation by an RCU callback function that might pass itself to call_rcu(). However, if any CPU other than the current one is not in dyntick-idle mode, fall back to simply checking (with fix to bug noted by Lai Jiangshan). Also, take advantage of last grace-period forcing, the opportunity to do so noted by Steve Rostedt. And apply simplified #ifdef condition suggested by Frederic Weisbecker. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1266887105-1528-15-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-06sched: Fix balance vs hotplug racePeter Zijlstra1-0/+2
Since (e761b77: cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment) we have cpu_active_mask which is suppose to rule scheduler migration and load-balancing, except it never (fully) did. The particular problem being solved here is a crash in try_to_wake_up() where select_task_rq() ends up selecting an offline cpu because select_task_rq_fair() trusts the sched_domain tree to reflect the current state of affairs, similarly select_task_rq_rt() trusts the root_domain. However, the sched_domains are updated from CPU_DEAD, which is after the cpu is taken offline and after stop_machine is done. Therefore it can race perfectly well with code assuming the domains are right. Cure this by building the domains from cpu_active_mask on CPU_DOWN_PREPARE. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-24cpumask: Move deprecated functions to end of header.Rusty Russell1-341/+252
The new ones have pretty kerneldoc. Move the old ones to the end to avoid confusing people. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: benh@kernel.crashing.org
2009-09-24cpumask: remove unused deprecated functions, avoid accusations of insanityRusty Russell1-111/+1
We're not forcing removal of the old cpu_ functions, but we might as well delete the now-unused ones. Especially CPUMASK_ALLOC and friends. I actually got a phone call (!) from a hacker who thought I had introduced them as the new cpumask API. He seemed bewildered that I had lost all taste. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: benh@kernel.crashing.org
2009-09-24cpumask: remove unused cpu_mask_allRusty Russell1-3/+0
It's only defined for NR_CPUS > BITS_PER_LONG; cpu_all_mask is always defined (and const). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-09-24cpumask: remove dangerous CPU_MASK_ALL_PTRRusty Russell1-3/+0
(Thanks to Al Viro for reminding me of this, via Ingo) CPU_MASK_ALL is the (deprecated) "all bits set" cpumask, defined as so: #define CPU_MASK_ALL (cpumask_t) { { ... } } Taking the address of such a temporary is questionable at best, unfortunately 321a8e9d (cpumask: add CPU_MASK_ALL_PTR macro) added CPU_MASK_ALL_PTR: #define CPU_MASK_ALL_PTR (&CPU_MASK_ALL) Which formalizes this practice. One day gcc could bite us over this usage (though we seem to have gotten away with it so far). Now all callers are removed, we kill it. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Reported-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Mike Travis <travis@sgi.com>
2009-09-23generic-ipi: make struct call_function_data locklessXiao Guangrong1-0/+12
This patch can remove spinlock from struct call_function_data, the reasons are below: 1: add a new interface for cpumask named cpumask_test_and_clear_cpu(), it can atomically test and clear specific cpu, we can use it instead of cpumask_test_cpu() and cpumask_clear_cpu() and no need data->lock to protect those in generic_smp_call_function_interrupt(). 2: in smp_call_function_many(), after csd_lock() return, the current's cfd_data is deleted from call_function list, so it not have race between other cpus, then cfs_data is only used in smp_call_function_many() that must disable preemption and not from a hardware interrupthandler or from a bottom half handler to call, only the correspond cpu can use it, so it not have race in current cpu, no need cfs_data->lock to protect it. 3: after 1 and 2, cfs_data->lock is only use to protect cfs_data->refs in generic_smp_call_function_interrupt(), so we can define cfs_data->refs to atomic_t, and no need cfs_data->lock any more. Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Peter Zijlstra <peterz@infradead.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au> [akpm@linux-foundation.org: use atomic_dec_return()] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-21Make bitmask 'and' operators return a result codeLinus Torvalds1-10/+10
When 'and'ing two bitmasks (where 'andnot' is a variation on it), some cases want to know whether the result is the empty set or not. In particular, the TLB IPI sending code wants to do cpumask operations and determine if there are any CPU's left in the final set. So this just makes the bitmask (and cpumask) functions return a boolean for whether the result has any bits set. Cc: stable@kernel.org (2.6.30, needed by TLB shootdown fix) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-09cpumask: introduce zalloc_cpumask_varYinghai Lu1-0/+15
So can get cpumask_var with cpumask_clear Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-01-01cpumask: CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONSRusty Russell1-1/+10
Impact: new debug CONFIG options This helps find unconverted code. It currently breaks compile horribly, but we never wanted a flag day so that's expected. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-12-30cpumask: make set_cpu_*/init_cpu_* out-of-lineRusty Russell1-46/+7
They're only for use in boot/cpu hotplug code anyway, and this avoids the use of deprecated cpu_*_map. Stephen Rothwell points out that gcc 4.2.4 (on powerpc at least) didn't like the cast away of const anyway: include/linux/cpumask.h: In function 'set_cpu_possible': include/linux/cpumask.h:1052: warning: passing argument 2 of 'cpumask_set_cpu' discards qualifiers from pointer target type So this kills two birds with one stone. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-12-30cpumask: make cpumask.h eat its own dogfood.Rusty Russell1-37/+38
Changes: 1) cpumask_t to struct cpumask, 2) cpus_weight_nr to cpumask_weight, 3) cpu_isset to cpumask_test_cpu, 4) ->bits to cpumask_bits() 5) cpu_*_map to cpu_*_mask. 6) for_each_cpu_mask_nr to for_each_cpu Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-12-30cpumask: switch over to cpu_online/possible/active/present_mask: coreRusty Russell1-46/+29
Impact: cleanup This implements the obsolescent cpu_online_map in terms of cpu_online_mask, rather than the other way around. Same for the other maps. The documentation comments are also updated to refer to _mask rather than _map. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Mike Travis <travis@sgi.com>
2008-12-19cpumask: Add alloc_cpumask_var_node()Mike Travis1-0/+7
Impact: New API This will be needed in x86 code to allocate the domain and old_domain cpumasks on the same node as where the containing irq_cfg struct is allocated. (Also fixes double-dump_stack on rare CONFIG_DEBUG_PER_CPU_MAPS case) Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (re-impl alloc_cpumask_var)
2008-12-13cpumask: Use all NR_CPUS bits unless CONFIG_CPUMASK_OFFSTACKRusty Russell1-4/+7
Impact: futureproof as we convert more code to new APIs The old cpumask operators treat all NR_CPUS bits as relevent, the new ones use nr_cpumask_bits. For large NR_CPUS and small nr_cpu_ids, this makes a difference. However, mixing the two can cause problems with undefined bits. An arch which sets CONFIG_CPUMASK_OFFSTACK should have converted across to the new operators, so it's safe in that case. (Thanks to Stephen Rothwell for bisecting the initial unused-bits bug, and Mike Travis for this solution). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Mike Travis <travis@sgi.com>
2008-12-13cpumask: change cpumask_scnprintf, cpumask_parse_user, cpulist_parse, and cpulist_scnprintf to take pointers.Rusty Russell1-30/+57
Impact: change calling convention of existing cpumask APIs Most cpumask functions started with cpus_: these have been replaced by cpumask_ ones which take struct cpumask pointers as expected. These four functions don't have good replacement names; fortunately they're rarely used, so we just change them over. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Mike Travis <travis@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: paulus@samba.org Cc: mingo@redhat.com Cc: tony.luck@intel.com Cc: ralf@linux-mips.org Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: cl@linux-foundation.org Cc: srostedt@redhat.com
2008-11-09cpumask: introduce new API, without changing anything, v3Rusty Russell1-6/+52
Impact: cleanup Clean up based on feedback from Andrew Morton and others: - change to inline functions instead of macros - add __init to bootmem method - add a missing debug check Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-07cpumask: new API, v2Rusty Russell1-0/+11
- add cpumask_of() - add free_bootmem_cpumask_var() Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-06cpumask: introduce new API, without changing anythingRusty Russell1-2/+500
Impact: introduce new APIs We want to deprecate cpumasks on the stack, as we are headed for gynormous numbers of CPUs. Eventually, we want to head towards an undefined 'struct cpumask' so they can never be declared on stack. 1) New cpumask functions which take pointers instead of copies. (cpus_* -> cpumask_*) 2) Several new helpers to reduce requirements for temporary cpumasks (cpumask_first_and, cpumask_next_and, cpumask_any_and) 3) Helpers for declaring cpumasks on or offstack for large NR_CPUS (cpumask_var_t, alloc_cpumask_var and free_cpumask_var) 4) 'struct cpumask' for explicitness and to mark new-style code. 5) Make iterator functions stop at nr_cpu_ids (a runtime constant), not NR_CPUS for time efficiency and for smaller dynamic allocations in future. 6) cpumask_copy() so we can allocate less than a full cpumask eventually (for alloc_cpumask_var), and so we can eliminate the 'struct cpumask' definition eventually. 7) work_on_cpu() helper for doing task on a CPU, rather than saving old cpumask for current thread and manipulating it. 8) smp_call_function_many() which is smp_call_function_mask() except taking a cpumask pointer. Note that this patch simply introduces the new functions and leaves the obsolescent ones in place. This is to simplify the transition patches. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-30cpumask: statement expressions confuse some versions of gccStephen Rothwell1-1/+1
when you take the address of the result. Noticed on a sparc64 compile using a version 3.4.5 cross compiler. kernel/time/tick-common.c: In function `tick_check_new_device': kernel/time/tick-common.c:210: error: invalid lvalue in unary `&' ... Just make it a regular expression. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28cpu masks: optimize and clean up cpumask_of_cpu()Linus Torvalds1-3/+23
Clean up and optimize cpumask_of_cpu(), by sharing all the zero words. Instead of stupidly generating all possible i=0...NR_CPUS 2^i patterns creating a huge array of constant bitmasks, realize that the zero words can be shared. In other words, on a 64-bit architecture, we only ever need 64 of these arrays - with a different bit set in one single world (with enough zero words around it so that we can create any bitmask by just offsetting in that big array). And then we just put enough zeroes around it that we can point every single cpumask to be one of those things. So when we have 4k CPU's, instead of having 4k arrays (of 4k bits each, with one bit set in each array - 2MB memory total), we have exactly 64 arrays instead, each 8k bits in size (64kB total). And then we just point cpumask(n) to the right position (which we can calculate dynamically). Once we have the right arrays, getting "cpumask(n)" ends up being: static inline const cpumask_t *get_cpu_mask(unsigned int cpu) { const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG]; p -= cpu / BITS_PER_LONG; return (const cpumask_t *)p; } This brings other advantages and simplifications as well: - we are not wasting memory that is just filled with a single bit in various different places - we don't need all those games to re-create the arrays in some dense format, because they're already going to be dense enough. if we compile a kernel for up to 4k CPU's, "wasting" that 64kB of memory is a non-issue (especially since by doing this "overlapping" trick we probably get better cache behaviour anyway). [ mingo@elte.hu: Converted Linus's mails into a commit. See: http://lkml.org/lkml/2008/7/27/156 http://lkml.org/lkml/2008/7/28/320 Also applied a family filter - which also has the side-effect of leaving out the bits where Linus calls me an idio... Oh, never mind ;-) ] Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-26cpumask: make cpumask_of_cpu_map genericMike Travis1-38/+3
If an arch doesn't define cpumask_of_cpu_map, create a generic statically-initialized one for them. This allows removal of the buggy cpumask_of_cpu() macro (&cpumask_of_cpu() gives address of out-of-scope var). An arch with NR_CPUS of 4096 probably wants to allocate this itself based on the actual number of CPUs, since otherwise they're using 2MB of rodata (1024 cpus means 128k). That's what CONFIG_HAVE_CPUMASK_OF_CPU_MAP is for (only x86/64 does so at the moment). In future as we support more CPUs, we'll need to resort to a get_cpu_map()/put_cpu_map() allocation scheme. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jack Steiner <steiner@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-23Merge branch 'sched/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tipLinus Torvalds1-1/+5
* 'sched/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: hrtick_enabled() should use cpu_active() sched, x86: clean up hrtick implementation sched: fix build error, provide partition_sched_domains() unconditionally sched: fix warning in inc_rt_tasks() to not declare variable 'rq' if it's not needed cpu hotplug: Make cpu_active_map synchronization dependency clear cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2) sched: rework of "prioritize non-migratable tasks over migratable ones" sched: reduce stack size in isolated_cpu_setup() Revert parts of "ftrace: do not trace scheduler functions" Fixed up conflicts in include/asm-x86/thread_info.h (due to the TIF_SINGLESTEP unification vs TIF_HRTICK_RESCHED removal) and kernel/sched_fair.c (due to cpu_active_map vs for_each_cpu_mask_nr() introduction).
2008-07-20cpumask: Provide a generic set of CPUMASK_ALLOC macros, FIXUPMike Travis1-7/+26
* Rename CPUMASK_VAR --> CPUMASK_PTR (and simplify) * Fix a semantic error in CPUMASK_ALLOC * Add a bit of commentry to cpumask.h Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18cpumask: Provide a generic set of CPUMASK_ALLOC macrosMike Travis1-0/+21
* Provide a generic set of CPUMASK_ALLOC macros patterned after the SCHED_CPUMASK_ALLOC macros. This is used where multiple cpumask_t variables are declared on the stack to reduce the amount of stack space required. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>