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authorKevin Hilman <khilman@linaro.org>2013-09-16 15:28:21 -0700
committerFrederic Weisbecker <fweisbec@gmail.com>2013-09-30 15:35:53 +0200
commit554b0004d0ec4fbd11e08668dfc400f211e8d5c5 (patch)
tree962305270252e407cd887ba9ed949bde346b8f81 /arch/Kconfig
parent15c03dd4859ab16f9212238f29dd315654aa94f6 (diff)
downloadlinux-554b0004d0ec4fbd11e08668dfc400f211e8d5c5.tar.gz
vtime: Add HAVE_VIRT_CPU_ACCOUNTING_GEN Kconfig
With VIRT_CPU_ACCOUNTING_GEN, cputime_t becomes 64-bit. In order to use that feature, arch code should be audited to ensure there are no races in concurrent read/write of cputime_t. For example, reading/writing 64-bit cputime_t on some 32-bit arches may require multiple accesses for low and high value parts, so proper locking is needed to protect against concurrent accesses. Therefore, add CONFIG_HAVE_VIRT_CPU_ACCOUNTING_GEN which arches can enable after they've been audited for potential races. This option is automatically enabled on 64-bit platforms. Feature requested by Frederic Weisbecker. Signed-off-by: Kevin Hilman <khilman@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Arm Linux <linux-arm-kernel@lists.infradead.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Diffstat (limited to 'arch/Kconfig')
-rw-r--r--arch/Kconfig12
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/Kconfig b/arch/Kconfig
index af2cc6eabcc..185f8b00764 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -353,6 +353,18 @@ config HAVE_CONTEXT_TRACKING
config HAVE_VIRT_CPU_ACCOUNTING
bool
+config HAVE_VIRT_CPU_ACCOUNTING_GEN
+ bool
+ default y if 64BIT
+ help
+ With VIRT_CPU_ACCOUNTING_GEN, cputime_t becomes 64-bit.
+ Before enabling this option, arch code must be audited
+ to ensure there are no races in concurrent read/write of
+ cputime_t. For example, reading/writing 64-bit cputime_t on
+ some 32-bit arches may require multiple accesses, so proper
+ locking is needed to protect against concurrent accesses.
+
+
config HAVE_IRQ_TIME_ACCOUNTING
bool
help