Date: Thu, 8 Oct 1998 17:24:51 -0700 (PDT) From: John Polstra <jdp@FreeBSD.ORG> To: cvs-committers@FreeBSD.ORG, cvs-all@FreeBSD.ORG Subject: cvs commit: src/sys/vm vm_zone.c Message-ID: <199810090024.RAA11054@freefall.freebsd.org>
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jdp 1998/10/08 17:24:51 PDT
Modified files:
sys/vm vm_zone.c
Log:
Fix a panic on SMP systems, caused by sleeping while holding a
simple-lock.
The reviewer raises the following caveat: "I believe these changes
open a non-critical race condition when adding memory to the pool
for the zone. I think what will happen is that you could have two
threads that are simultaneously adding additional memory when the
pool runs out. This appears to not be a problem, however, since
the re-aquisition of the lock will protect the list pointers."
The submitter agrees that the race is non-critical, and points out
that it already existed for the non-SMP case. He suggests that
perhaps a sleep lock (using the lock manager) should be used to
close that race. This might be worth revisiting after 3.0 is
released.
Reviewed by: dg (David Greenman)
Submitted by: tegge (Tor Egge)
Revision Changes Path
1.22 +13 -1 src/sys/vm/vm_zone.c
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