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fix a problem with bad performance after wakeup caused by r333321

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This change reverts a "while here" part of r333321 that moved clearing
of suspended_cpus to an earlier place.

Apparently, there can be a problem when modifying (shared) memory before
restoring proper cache attributes.  So, to be safe, move the clearing to
the old place.

Many thanks to Johannes Lundberg for bisecting the changes to that
particular commit and then bisecting the commit to the particular
change.

Reported by:	many
Debugged by:	Johannes Lundberg <johalun0@gmail.com>
MFC after:	1 week
X-MFC with:	r333321
This commit is contained in:
Andriy Gapon 2018-05-17 10:16:20 +00:00
parent bb5125a411
commit 7973b47369
1 changed files with 3 additions and 2 deletions
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5
sys/x86/x86/mp_x86.c
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@ -1457,8 +1457,6 @@ cpususpend_handler(void)
*/
wbinvd();
} else {
/* Indicate that we have restarted and restored the context. */
CPU_CLR_ATOMIC(cpu, &suspended_cpus);
#ifdef __amd64__
fpuresume(susppcbs[cpu]->sp_fpususpend);
#else
@ -1468,6 +1466,9 @@ cpususpend_handler(void)
initializecpu();
PCPU_SET(switchtime, 0);
PCPU_SET(switchticks, ticks);
/* Indicate that we have restarted and restored the context. */
CPU_CLR_ATOMIC(cpu, &suspended_cpus);
}
/* Wait for resume directive */