The following commit has been merged into the sched/rt branch of tip: Commit-ID: 4e139c7711633365ebb52fbb63905395522a8413 Gitweb: https://git.kernel.org/tip/4e139c7711633365ebb52fbb63905395522a8413 Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx> AuthorDate: Fri, 14 Feb 2020 14:39:19 +01:00 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitterDate: Thu, 20 Feb 2020 21:17:24 +01:00 sched: Provide cant_migrate() 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@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/20200214161503.070487511@xxxxxxxxxxxxx --- include/linux/kernel.h | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 0d9db2a..9b7a8d7 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -257,6 +257,13 @@ extern void __cant_sleep(const char *file, int line, int preempt_offset); #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.
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