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| author | Akira Takeuchi <takeuchi.akr@jp.panasonic.com> | 2010-10-27 17:28:52 +0100 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2010-10-27 17:28:52 +0100 |
| commit | 278d91c4609d55202c1e63d5fc5f01466cc7bbab (patch) | |
| tree | 8b0c863837508959430c1741e2e5a2d37d2890d4 /arch/mn10300/Kconfig | |
| parent | 965ea4bbb9ae926358273368144ba838c561bc38 (diff) | |
| download | op-kernel-dev-278d91c4609d55202c1e63d5fc5f01466cc7bbab.zip op-kernel-dev-278d91c4609d55202c1e63d5fc5f01466cc7bbab.tar.gz | |
MN10300: Make the FPU operate in non-lazy mode under SMP
Make the FPU operate in non-lazy mode under SMP so that when the process that
is currently using the FPU migrates to a different CPU, we don't have to ping
its previous CPU to flush the FPU context.
Signed-off-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: Kiyoshi Owada <owada.kiyoshi@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'arch/mn10300/Kconfig')
| -rw-r--r-- | arch/mn10300/Kconfig | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/mn10300/Kconfig b/arch/mn10300/Kconfig index 7bd920b..a1f334c 100644 --- a/arch/mn10300/Kconfig +++ b/arch/mn10300/Kconfig @@ -140,6 +140,21 @@ config FPU default y depends on MN10300_PROC_MN103E010 +config LAZY_SAVE_FPU + bool "Save FPU state lazily" + default y + depends on FPU && !SMP + help + Enable this to be lazy in the saving of the FPU state to the owning + task's thread struct. This is useful if most tasks on the system + don't use the FPU as only those tasks that use it will pass it + between them, and the state needn't be saved for a task that isn't + using it. + + This can't be so easily used on SMP as the process that owns the FPU + state on a CPU may be currently running on another CPU, so for the + moment, it is disabled. + source "arch/mn10300/mm/Kconfig.cache" config MN10300_TLB_USE_PIDR |
