Commit-ID: 3b6f70fd7dd4e19fc674ec99e389bf0da5589525 Gitweb: http://git.kernel.org/tip/3b6f70fd7dd4e19fc674ec99e389bf0da5589525 Author: Yong Zhang <yong.zhang0@xxxxxxxxx> AuthorDate: Tue, 29 May 2012 15:16:01 +0800 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitDate: Tue, 5 Jun 2012 17:27:12 +0200 x86-smp-remove-call-to-ipi_call_lock-ipi_call_unlock ipi_call_lock/unlock() lock resp. unlock call_function.lock. This lock protects only the call_function data structure itself, but it's completely unrelated to cpu_online_mask. The mask to which the IPIs are sent is calculated before call_function.lock is taken in smp_call_function_many(), so the locking around set_cpu_online() is pointless and can be removed. [ tglx: Massaged changelog ] Signed-off-by: Yong Zhang <yong.zhang0@xxxxxxxxx> Cc: ralf@xxxxxxxxxxxxxx Cc: sshtylyov@xxxxxxxxxx Cc: david.daney@xxxxxxxxxx Cc: nikunj@xxxxxxxxxxxxxxxxxx Cc: paulmck@xxxxxxxxxxxxxxxxxx Cc: axboe@xxxxxxxxx Cc: peterz@xxxxxxxxxxxxx Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> Cc: Jeremy Fitzhardinge <jeremy@xxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Link: http://lkml.kernel.org/r/1338275765-3217-7-git-send-email-yong.zhang0@xxxxxxxxx Acked-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx> Acked-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> --- arch/x86/kernel/smpboot.c | 9 --------- arch/x86/xen/smp.c | 2 -- 2 files changed, 0 insertions(+), 11 deletions(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index f56f96d..b2fd28f 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -255,22 +255,13 @@ notrace static void __cpuinit start_secondary(void *unused) check_tsc_sync_target(); /* - * We need to hold call_lock, so there is no inconsistency - * between the time smp_call_function() determines number of - * IPI recipients, and the time when the determination is made - * for which cpus receive the IPI. Holding this - * lock helps us to not include this cpu in a currently in progress - * smp_call_function(). - * * We need to hold vector_lock so there the set of online cpus * does not change while we are assigning vectors to cpus. Holding * this lock ensures we don't half assign or remove an irq from a cpu. */ - ipi_call_lock(); lock_vector_lock(); set_cpu_online(smp_processor_id(), true); unlock_vector_lock(); - ipi_call_unlock(); per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE; x86_platform.nmi_init(); diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index afb250d..f58dca7 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -80,9 +80,7 @@ static void __cpuinit cpu_bringup(void) notify_cpu_starting(cpu); - ipi_call_lock(); set_cpu_online(cpu, true); - ipi_call_unlock(); this_cpu_write(cpu_state, CPU_ONLINE); -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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