Date: Fri, 6 Nov 2009 10:15:15 +0000 (UTC) From: Attilio Rao <attilio@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-8@freebsd.org Subject: svn commit: r198977 - in stable/8/sys: amd64/amd64 i386/i386 Message-ID: <200911061015.nA6AFFMK012872@svn.freebsd.org>
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Author: attilio Date: Fri Nov 6 10:15:15 2009 New Revision: 198977 URL: http://svn.freebsd.org/changeset/base/198977 Log: MFC r198868, r198950: Opteron rev E family of processor expose a bug where acq memory barriers can be broken, resulting in random breakages. Printout a warning message if affecred family and model are found. Modified: stable/8/sys/amd64/amd64/identcpu.c stable/8/sys/i386/i386/identcpu.c Directory Properties: stable/8/sys/ (props changed) stable/8/sys/amd64/include/xen/ (props changed) stable/8/sys/cddl/contrib/opensolaris/ (props changed) stable/8/sys/contrib/dev/acpica/ (props changed) stable/8/sys/contrib/pf/ (props changed) stable/8/sys/dev/xen/xenpci/ (props changed) Modified: stable/8/sys/amd64/amd64/identcpu.c ============================================================================== --- stable/8/sys/amd64/amd64/identcpu.c Fri Nov 6 10:07:38 2009 (r198976) +++ stable/8/sys/amd64/amd64/identcpu.c Fri Nov 6 10:15:15 2009 (r198977) @@ -607,6 +607,21 @@ print_AMD_info(void) printf(", %d lines/tag", (regs[2] >> 8) & 0x0f); print_AMD_l2_assoc((regs[2] >> 12) & 0x0f); } + + /* + * Opteron Rev E shows a bug as in very rare occasions a read memory + * barrier is not performed as expected if it is followed by a + * non-atomic read-modify-write instruction. + * As long as that bug pops up very rarely (intensive machine usage + * on other operating systems generally generates one unexplainable + * crash any 2 months) and as long as a model specific fix would be + * impratical at this stage, print out a warning string if the broken + * model and family are identified. + */ + if (CPUID_TO_FAMILY(cpu_id) == 0xf && CPUID_TO_MODEL(cpu_id) >= 0x20 && + CPUID_TO_MODEL(cpu_id) <= 0x3f) + printf("WARNING: This architecture revision has known SMP " + "hardware bugs which may cause random instability\n"); } static void Modified: stable/8/sys/i386/i386/identcpu.c ============================================================================== --- stable/8/sys/i386/i386/identcpu.c Fri Nov 6 10:07:38 2009 (r198976) +++ stable/8/sys/i386/i386/identcpu.c Fri Nov 6 10:15:15 2009 (r198977) @@ -1303,6 +1303,21 @@ print_AMD_info(void) (amd_whcr & 0x0100) ? "Enable" : "Disable"); } } + + /* + * Opteron Rev E shows a bug as in very rare occasions a read memory + * barrier is not performed as expected if it is followed by a + * non-atomic read-modify-write instruction. + * As long as that bug pops up very rarely (intensive machine usage + * on other operating systems generally generates one unexplainable + * crash any 2 months) and as long as a model specific fix would be + * impratical at this stage, print out a warning string if the broken + * model and family are identified. + */ + if (CPUID_TO_FAMILY(cpu_id) == 0xf && CPUID_TO_MODEL(cpu_id) >= 0x20 && + CPUID_TO_MODEL(cpu_id) <= 0x3f) + printf("WARNING: This architecture revision has known SMP " + "hardware bugs which may cause random instability\n"); } static void
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