From: Peter Zijlstra <peterz@infradead.org>
To: Nadav Amit <namit@vmware.com>
Cc: Ingo Molnar <mingo@redhat.com>, Andy Lutomirski <luto@kernel.org>,
Borislav Petkov <bp@alien8.de>,
linux-kernel@vger.kernel.org, Rik van Riel <riel@surriel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Josh Poimboeuf <jpoimboe@redhat.com>
Subject: Re: [RFC PATCH 3/6] smp: Run functions concurrently in smp_call_function_many()
Date: Mon, 27 May 2019 11:15:34 +0200 [thread overview]
Message-ID: <20190527091534.GS2623@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20190525082203.6531-4-namit@vmware.com>
> + /*
> + * Choose the most efficient way to send an IPI. Note that the
> + * number of CPUs might be zero due to concurrent changes to the
> + * provided mask or cpu_online_mask.
> + */
Since we have preemption disabled here, I don't think online mask can
shrink, cpu-offline uses stop_machine().
> + if (nr_cpus == 1)
> + arch_send_call_function_single_ipi(last_cpu);
> + else if (likely(nr_cpus > 1))
> + arch_send_call_function_ipi_mask(cfd->cpumask_ipi);
> + }
next prev parent reply other threads:[~2019-05-27 9:15 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-25 8:21 [RFC PATCH 0/6] x86/mm: Flush remote and local TLBs concurrently Nadav Amit
2019-05-25 8:21 ` [RFC PATCH 1/6] smp: Remove smp_call_function() and on_each_cpu() return values Nadav Amit
2019-05-25 8:21 ` [RFC PATCH 2/6] cpumask: Purify cpumask_next() Nadav Amit
2019-05-25 8:32 ` Ingo Molnar
2019-05-27 8:30 ` Peter Zijlstra
2019-05-27 17:34 ` Nadav Amit
2019-05-25 8:22 ` [RFC PATCH 3/6] smp: Run functions concurrently in smp_call_function_many() Nadav Amit
2019-05-27 9:15 ` Peter Zijlstra [this message]
2019-05-27 17:39 ` Nadav Amit
2019-05-25 8:22 ` [RFC PATCH 4/6] x86/mm/tlb: Refactor common code into flush_tlb_on_cpus() Nadav Amit
2019-05-27 9:24 ` Peter Zijlstra
2019-05-27 18:59 ` Nadav Amit
2019-05-27 19:14 ` Peter Zijlstra
2019-05-25 8:22 ` [RFC PATCH 5/6] x86/mm/tlb: Flush remote and local TLBs concurrently Nadav Amit
2019-05-25 8:38 ` Nadav Amit
2019-05-25 8:54 ` Juergen Gross
2019-05-27 9:47 ` Peter Zijlstra
2019-05-27 10:21 ` Paolo Bonzini
2019-05-27 12:32 ` Peter Zijlstra
2019-05-27 12:45 ` Paolo Bonzini
2019-05-27 17:49 ` Nadav Amit
2019-05-25 8:22 ` [RFC PATCH 6/6] x86/mm/tlb: Optimize local TLB flushes Nadav Amit
2019-05-27 8:28 ` [RFC PATCH 0/6] x86/mm: Flush remote and local TLBs concurrently Peter Zijlstra
2019-05-27 9:59 ` Peter Zijlstra
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