mirror of https://gitee.com/openkylin/linux.git
b0e5c77903
For each logical CPU that is coming online, we spend 20msec for checking the TSC synchronization. And as this is done sequentially for each logical CPU boot, this time gets added up depending on the number of logical CPU's supported by the platform. Minimize this by using the socket topology information. If the target CPU coming online doesn't have any of its core-siblings online, a timeout of 20msec will be used for the TSC-warp measurement loop. Otherwise a smaller timeout of 2msec will be used, as we have some information about this socket already (and this information grows as we have more and more logical-siblings in that socket). Ideally we should be able to skip the TSC sync check on the other core-siblings, if the first logical CPU in a socket passed the sync test. But as the TSC is per-logical CPU and can potentially be modified wrongly by the bios before the OS boot, TSC sync test for smaller duration should be able to catch such errors. Also this will catch the condition where all the cores in the socket doesn't get reset at the same time. For example, with this modification, time spent in TSC sync checks on a 4 socket 10-core with HT system gets reduced from 1580msec to 212msec. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Jack Steiner <steiner@sgi.com> Cc: venki@google.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1328581940.29790.20.camel@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu> |
||
|---|---|---|
| .. | ||
| alpha | ||
| arm | ||
| avr32 | ||
| blackfin | ||
| c6x | ||
| cris | ||
| frv | ||
| h8300 | ||
| hexagon | ||
| ia64 | ||
| m32r | ||
| m68k | ||
| microblaze | ||
| mips | ||
| mn10300 | ||
| openrisc | ||
| parisc | ||
| powerpc | ||
| s390 | ||
| score | ||
| sh | ||
| sparc | ||
| tile | ||
| um | ||
| unicore32 | ||
| x86 | ||
| xtensa | ||
| .gitignore | ||
| Kconfig | ||