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Date:      Mon, 2 Apr 2018 07:45:13 +0000 (UTC)
From:      Andriy Gapon <avg@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r331874 - in head/sys: amd64/amd64 i386/i386
Message-ID:  <201804020745.w327jDOO089791@repo.freebsd.org>
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Author: avg
Date: Mon Apr  2 07:45:13 2018
New Revision: 331874
URL: https://svnweb.freebsd.org/changeset/base/331874

Log:
  x86 cpu_reset_proxy: no need to stop_cpus() the original processor
  
  The processor is "parked" in a spin-loop already and that's sufficient
  for the reset.  There is nothing that stop_cpus() would add here, only
  extra complexity and fragility.
  The original processor does not need to enable interrupts now, in fact,
  it must not do that.
  
  MFC after:	2 weeks

Modified:
  head/sys/amd64/amd64/vm_machdep.c
  head/sys/i386/i386/vm_machdep.c

Modified: head/sys/amd64/amd64/vm_machdep.c
==============================================================================
--- head/sys/amd64/amd64/vm_machdep.c	Mon Apr  2 05:15:25 2018	(r331873)
+++ head/sys/amd64/amd64/vm_machdep.c	Mon Apr  2 07:45:13 2018	(r331874)
@@ -569,14 +569,11 @@ cpu_set_user_tls(struct thread *td, void *tls_base)
 static void
 cpu_reset_proxy()
 {
-	cpuset_t tcrp;
 
 	cpu_reset_proxy_active = 1;
 	while (cpu_reset_proxy_active == 1)
 		ia32_pause(); /* Wait for other cpu to see that we've started */
 
-	CPU_SETOF(cpu_reset_proxyid, &tcrp);
-	stop_cpus(tcrp);
 	printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid);
 	DELAY(1000000);
 	cpu_reset_real();
@@ -616,7 +613,6 @@ cpu_reset()
 			}
 			if (cpu_reset_proxy_active == 0)
 				printf("cpu_reset: Failed to restart BSP\n");
-			enable_intr();
 			cpu_reset_proxy_active = 2;
 
 			while (1)

Modified: head/sys/i386/i386/vm_machdep.c
==============================================================================
--- head/sys/i386/i386/vm_machdep.c	Mon Apr  2 05:15:25 2018	(r331873)
+++ head/sys/i386/i386/vm_machdep.c	Mon Apr  2 07:45:13 2018	(r331874)
@@ -581,14 +581,11 @@ kvtop(void *addr)
 static void
 cpu_reset_proxy()
 {
-	cpuset_t tcrp;
 
 	cpu_reset_proxy_active = 1;
 	while (cpu_reset_proxy_active == 1)
 		ia32_pause(); /* Wait for other cpu to see that we've started */
 
-	CPU_SETOF(cpu_reset_proxyid, &tcrp);
-	stop_cpus(tcrp);
 	printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid);
 	DELAY(1000000);
 	cpu_reset_real();
@@ -628,7 +625,6 @@ cpu_reset()
 			}
 			if (cpu_reset_proxy_active == 0)
 				printf("cpu_reset: Failed to restart BSP\n");
-			enable_intr();
 			cpu_reset_proxy_active = 2;
 
 			while (1)

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