Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
[PATCH] x86_64: Only do the clustered systems have unsynchronized TSC assumption on IBM systems
Big Unisys systems have multiple clusters too, but they have an
synchronized TSC.
I'm using the SMBIOS to check for vendor == IBM.
Cc: Chris McDermott <lcm@us.ibm.com>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@unisys.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
authored by
Andi Kleen
and committed by
Linus Torvalds
13a229ab
5342fba5
+22
-4
-3
arch/i386/kernel/acpi/boot.c
-3
arch/i386/kernel/acpi/boot.c
+8
-1
arch/x86_64/kernel/apic.c
+8
-1
arch/x86_64/kernel/apic.c
···
962
962
irq_exit();
963
963
}
964
964
965
+
int __initdata unsync_tsc_on_multicluster;
966
+
965
967
/*
966
968
* oem_force_hpet_timer -- force HPET mode for some boxes.
967
969
*
968
970
* Thus far, the major user of this is IBM's Summit2 series:
969
971
*
970
-
* Clustered boxes may have unsynced TSC problems if they are
972
+
* Some clustered boxes may have unsynced TSC problems if they are
971
973
* multi-chassis. Use available data to take a good guess.
972
974
* If in doubt, go HPET.
973
975
*/
···
978
976
int i, clusters, zeros;
979
977
unsigned id;
980
978
DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
979
+
980
+
/* Only do this check on IBM machines - big Unisys systems
981
+
use multiple clusters too, but have synchronized TSC */
982
+
if (!unsync_tsc_on_multicluster)
983
+
return 0;
981
984
982
985
bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
983
986
+14
include/asm-x86_64/acpi.h
+14
include/asm-x86_64/acpi.h
···
164
164
165
165
extern int acpi_skip_timer_override;
166
166
167
+
extern int unsync_tsc_on_multicluster;
168
+
169
+
static inline int acpi_madt_oem_check(char *oem, char *productid)
170
+
{
171
+
/* Copied from i386. Probably has too many entries. */
172
+
if (!strncmp(oem, "IBM ENSW", 8) &&
173
+
(!strncmp(productid, "VIGIL SMP", 9)
174
+
|| !strncmp(productid, "EXA", 3)
175
+
|| !strncmp(productid, "RUTHLESS SMP", 12))) {
176
+
unsync_tsc_on_multicluster = 1;
177
+
}
178
+
return 0;
179
+
}
180
+
167
181
#endif /*__KERNEL__*/
168
182
169
183
#endif /*_ASM_ACPI_H*/