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| author | Marco Elver <elver@google.com> | 2022-03-22 14:48:25 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-22 15:57:11 -0700 |
| commit | 737b6a10ac19e41877aa1911bf6b361a72a88ad9 (patch) | |
| tree | a8e23366c9b1d6e3a5fa2220505fc175f2862a3b /lib/Kconfig.kfence | |
| parent | 3cb1c9620eeeb67c614c0732a35861b0b1efdc53 (diff) | |
| download | lwn-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.kfence | 12 |
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 |