The patch titled Subject: smp: add func to IPI cpus based on parameter func has been added to the -mm tree. Its filename is smp-add-func-to-ipi-cpus-based-on-parameter-func.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Gilad Ben-Yossef <gilad@xxxxxxxxxxxxx> Subject: smp: add func to IPI cpus based on parameter func Add the on_each_cpu_cond() function that wraps on_each_cpu_mask() and calculates the cpumask of cpus to IPI by calling a function supplied as a parameter in order to determine whether to IPI each specific cpu. The function works around allocation failure of cpumask variable in CONFIG_CPUMASK_OFFSTACK=y by itereating over cpus sending an IPI a time via smp_call_function_single(). The function is useful since it allows to seperate the specific code that decided in each case whether to IPI a specific cpu for a specific request from the common boilerplate code of handling creating the mask, handling failures etc. Signed-off-by: Gilad Ben-Yossef <gilad@xxxxxxxxxxxxx> Cc: Chris Metcalf <cmetcalf@xxxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx> Acked-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx> Cc: Russell King <linux@xxxxxxxxxxxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxx> Cc: Matt Mackall <mpm@xxxxxxxxxxx> Cc: Sasha Levin <levinsasha928@xxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Andi Kleen <andi@xxxxxxxxxxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Avi Kivity <avi@xxxxxxxxxx> Cc: Michal Nazarewicz <mina86@xxxxxxxxxx> Cc: Kosaki Motohiro <kosaki.motohiro@xxxxxxxxx> Cc: Milton Miller <miltonm@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/smp.h | 19 +++++++++++++ kernel/smp.c | 58 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 77 insertions(+) diff -puN include/linux/smp.h~smp-add-func-to-ipi-cpus-based-on-parameter-func include/linux/smp.h --- a/include/linux/smp.h~smp-add-func-to-ipi-cpus-based-on-parameter-func +++ a/include/linux/smp.h @@ -109,6 +109,15 @@ void on_each_cpu_mask(const struct cpuma void *info, bool wait); /* + * Call a function on each processor for which the supplied function + * cond_func returns a positive value. This may include the local + * processor. + */ +void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info), + smp_call_func_t func, void *info, bool wait, + gfp_t gfpflags); + +/* * Mark the boot cpu "online" so that it can call console drivers in * printk() and can access its per-cpu storage. */ @@ -153,6 +162,16 @@ static inline int up_smp_call_function(s local_irq_enable(); \ } \ } while (0) +#define on_each_cpu_cond(cond_func, func, info, wait, gfpflags) \ + do { \ + preempt_disable(); \ + if (cond_func(0, info)) { \ + local_irq_disable(); \ + (func)(info); \ + local_irq_enable(); \ + } \ + preempt_enable(); \ + } while (0) static inline void smp_send_reschedule(int cpu) { } #define num_booting_cpus() 1 diff -puN kernel/smp.c~smp-add-func-to-ipi-cpus-based-on-parameter-func kernel/smp.c --- a/kernel/smp.c~smp-add-func-to-ipi-cpus-based-on-parameter-func +++ a/kernel/smp.c @@ -730,3 +730,61 @@ void on_each_cpu_mask(const struct cpuma put_cpu(); } EXPORT_SYMBOL(on_each_cpu_mask); + +/* + * on_each_cpu_cond(): Call a function on each processor for which + * the supplied function cond_func returns true, optionally waiting + * for all the required CPUs to finish. This may include the local + * processor. + * @cond_func: A callback function that is passed a cpu id and + * the the info parameter. The function is called + * with preemption disabled. The function should + * return a blooean value indicating whether to IPI + * the specified CPU. + * @func: The function to run on all applicable CPUs. + * This must be fast and non-blocking. + * @info: An arbitrary pointer to pass to both functions. + * @wait: If true, wait (atomically) until function has + * completed on other CPUs. + * @gfpflags: GFP flags to use when allocating the cpumask + * used internally by the function. + * + * The function might sleep if the GFP flags indicates a non + * atomic allocation is allowed. + * + * You must not call this function with disabled interrupts or + * from a hardware interrupt handler or from a bottom half handler. + */ +void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info), + smp_call_func_t func, void *info, bool wait, + gfp_t gfpflags) +{ + cpumask_var_t cpus; + int cpu, ret; + + might_sleep_if(gfpflags & __GFP_WAIT); + + if (likely(zalloc_cpumask_var(&cpus, (gfpflags|__GFP_NOWARN)))) { + preempt_disable(); + for_each_online_cpu(cpu) + if (cond_func(cpu, info)) + cpumask_set_cpu(cpu, cpus); + on_each_cpu_mask(cpus, func, info, wait); + preempt_enable(); + free_cpumask_var(cpus); + } else { + /* + * No free cpumask, bother. No matter, we'll + * just have to IPI them one by one. + */ + preempt_disable(); + for_each_online_cpu(cpu) + if (cond_func(cpu, info)) { + ret = smp_call_function_single(cpu, func, + info, wait); + WARN_ON_ONCE(!ret); + } + preempt_enable(); + } +} +EXPORT_SYMBOL(on_each_cpu_cond); _ Subject: Subject: smp: add func to IPI cpus based on parameter func Patches currently in -mm which might be from gilad@xxxxxxxxxxxxx are smp-introduce-a-generic-on_each_cpu_mask-function.patch arm-move-arm-over-to-generic-on_each_cpu_mask.patch tile-move-tile-to-use-generic-on_each_cpu_mask.patch smp-add-func-to-ipi-cpus-based-on-parameter-func.patch smp-add-func-to-ipi-cpus-based-on-parameter-func-fix.patch slub-only-ipi-cpus-that-have-per-cpu-obj-to-flush.patch fs-only-send-ipi-to-invalidate-lru-bh-when-needed.patch mm-only-ipi-cpus-to-drain-local-pages-if-they-exist.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html