From: "Paul E. McKenney" <[email protected]> POSIX timers are no longer starved on adaptive-ticks CPUs. Instead, they prevent affected CPUs from entering adaptive-ticks mode. This commit therefore updates the NO_HZ.txt documentation.
Signed-off-by: Paul E. McKenney <[email protected]> --- Documentation/timers/NO_HZ.txt | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/Documentation/timers/NO_HZ.txt b/Documentation/timers/NO_HZ.txt index cca122f25120..6eaf576294f3 100644 --- a/Documentation/timers/NO_HZ.txt +++ b/Documentation/timers/NO_HZ.txt @@ -158,13 +158,9 @@ not come for free: to the need to inform kernel subsystems (such as RCU) about the change in mode. -3. POSIX CPU timers on adaptive-tick CPUs may miss their deadlines - (perhaps indefinitely) because they currently rely on - scheduling-tick interrupts. This will likely be fixed in - one of two ways: (1) Prevent CPUs with POSIX CPU timers from - entering adaptive-tick mode, or (2) Use hrtimers or other - adaptive-ticks-immune mechanism to cause the POSIX CPU timer to - fire properly. +3. POSIX CPU timers prevent CPUs from entering adaptive-tick mode. + Real-time applications needing to take actions based on CPU time + consumption need to use other means of doing so. 4. If there are more perf events pending than the hardware can accommodate, they are normally round-robined so as to collect -- 1.8.1.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
