Date: Sat, 23 May 2015 22:28:59 +0000 (UTC) From: Andrew Turner <andrew@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r283331 - head/sys/arm/arm Message-ID: <201505232228.t4NMSxs2032365@svn.freebsd.org>
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Author: andrew Date: Sat May 23 22:28:59 2015 New Revision: 283331 URL: https://svnweb.freebsd.org/changeset/base/283331 Log: Use the wait-for-event instruction to put the core we have just enabled to sleep while it waits to start scheduling. The boot core can then use the send-event instruction to wake the cores when they should enter the scheduler. MFC after: 1 week Modified: head/sys/arm/arm/mp_machdep.c Modified: head/sys/arm/arm/mp_machdep.c ============================================================================== --- head/sys/arm/arm/mp_machdep.c Sat May 23 21:58:41 2015 (r283330) +++ head/sys/arm/arm/mp_machdep.c Sat May 23 22:28:59 2015 (r283331) @@ -185,8 +185,11 @@ init_secondary(int cpu) atomic_add_rel_32(&mp_naps, 1); /* Spin until the BSP releases the APs */ - while (!aps_ready) - ; + while (!atomic_load_acq_int(&aps_ready)) { +#if __ARM_ARCH >= 7 + __asm __volatile("wfe"); +#endif + } /* Initialize curthread */ KASSERT(PCPU_GET(idlethread) != NULL, ("no idle thread")); @@ -353,6 +356,10 @@ release_aps(void *dummy __unused) arm_unmask_irq(i); } atomic_store_rel_int(&aps_ready, 1); + /* Wake the other threads up */ +#if __ARM_ARCH >= 7 + armv7_sev(); +#endif printf("Release APs\n");
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