| Message ID | 20200214161503.070487511@linutronix.de |
|---|---|
| State | RFC |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | bpf: Make BPF and PREEMPT_RT co-exist | expand |
--- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -257,6 +257,13 @@ extern void __cant_sleep(const char *fil #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0) +#ifndef CONFIG_PREEMPT_RT +# define cant_migrate() cant_sleep() +#else + /* Placeholder for now */ +# define cant_migrate() do { } while (0) +#endif + /** * abs - return absolute value of an argument * @x: the value. If it is unsigned type, it is converted to signed type first.
Some code pathes rely on preempt_disable() to prevent migration on a non RT enabled kernel. These preempt_disable/enable() pairs are substituted by migrate_disable/enable() pairs or other forms of RT specific protection. On RT these protections prevent migration but not preemption. Obviously a cant_sleep() check in such a section will trigger on RT because preemption is not disabled. Provide a cant_migrate() macro which maps to cant_sleep() on a non RT kernel and an empty placeholder for RT for now. The placeholder will be changed to a proper debug check along with the RT specific migration protection mechanism. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- include/linux/kernel.h | 7 +++++++ 1 file changed, 7 insertions(+)