Messages in this thread Patch in this message | | | Date | Fri, 01 Jun 2012 17:42:54 +0530 | From | "Srivatsa S. Bhat" <> | Subject | Re: [PATCH 02/27] smpboot: Add provisions for arch-specific locking around cpu_online_mask |
| |
Adding arch maintainers to Cc, which I had missed earlier. No changes to the patch.
======
From: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Subject: [PATCH 02/27] smpboot: Add provisions for arch-specific locking around cpu_online_mask
We want to make smp booting as generic as possible and remove code duplication in arch/ directories.
While manipulating the cpu_online_mask, x86 uses an additional lock, i.e., 'vector_lock'. So provide a generic way to implement such arch-specific extra locking, by providing weakly defined functions arch_vector_lock() and arch_vector_unlock() which can be overriden by different architectures suitably.
Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Venkatesh Pallipadi <venki@google.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: David Howells <dhowells@redhat.com> Cc: Bob Liu <lliubbo@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Richard Weinberger <richard@nod.at> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Matt Turner <mattst88@gmail.com> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> ---
kernel/smpboot.c | 11 ++++++++++- 1 files changed, 10 insertions(+), 1 deletions(-)
diff --git a/kernel/smpboot.c b/kernel/smpboot.c index 6c26133..5ae1805 100644 --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -107,6 +107,13 @@ void __weak __cpu_pre_online(void *arg) {} void __weak __cpu_post_online(void *arg) {} #endif +/* + * Optional arch-specific locking for manipulating cpu_online_mask while + * bringing up secondary CPUs. + */ +void __weak arch_vector_lock(void) {} +void __weak arch_vector_unlock(void) {} + /** * smpboot_start_secondary - Generic way to boot secondary processors @@ -129,8 +136,10 @@ void __cpuinit smpboot_start_secondary(void *arg) __cpu_pre_online(arg); - /* Set the CPU in the cpu_online_mask */ + /* Set the CPU in the cpu_online_mask with required locks held */ + arch_vector_lock(); set_cpu_online(cpu, true); + arch_vector_unlock(); __cpu_post_online(arg);
| |