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authorMarco Elver <elver@google.com>2022-03-22 14:48:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-22 15:57:11 -0700
commit737b6a10ac19e41877aa1911bf6b361a72a88ad9 (patch)
treea8e23366c9b1d6e3a5fa2220505fc175f2862a3b /lib/Kconfig.kfence
parent3cb1c9620eeeb67c614c0732a35861b0b1efdc53 (diff)
downloadlwn-737b6a10ac19e41877aa1911bf6b361a72a88ad9.tar.gz
lwn-737b6a10ac19e41877aa1911bf6b361a72a88ad9.zip
kfence: allow use of a deferrable timer
Allow the use of a deferrable timer, which does not force CPU wake-ups when the system is idle. A consequence is that the sample interval becomes very unpredictable, to the point that it is not guaranteed that the KFENCE KUnit test still passes. Nevertheless, on power-constrained systems this may be preferable, so let's give the user the option should they accept the above trade-off. Link: https://lkml.kernel.org/r/20220308141415.3168078-1-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/Kconfig.kfence')
-rw-r--r--lib/Kconfig.kfence12
1 files changed, 12 insertions, 0 deletions
diff --git a/lib/Kconfig.kfence b/lib/Kconfig.kfence
index 912f252a41fc..459dda9ef619 100644
--- a/lib/Kconfig.kfence
+++ b/lib/Kconfig.kfence
@@ -45,6 +45,18 @@ config KFENCE_NUM_OBJECTS
pages are required; with one containing the object and two adjacent
ones used as guard pages.
+config KFENCE_DEFERRABLE
+ bool "Use a deferrable timer to trigger allocations"
+ help
+ Use a deferrable timer to trigger allocations. This avoids forcing
+ CPU wake-ups if the system is idle, at the risk of a less predictable
+ sample interval.
+
+ Warning: The KUnit test suite fails with this option enabled - due to
+ the unpredictability of the sample interval!
+
+ Say N if you are unsure.
+
config KFENCE_STATIC_KEYS
bool "Use static keys to set up allocations" if EXPERT
depends on JUMP_LABEL