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Add P-RES scheduler plugin P-RES: the partitioned reservation-based scheduler. A simple partitioned scheduler that provides a reservation environment on each core, based on the generic reservations code. Hierarchical scheduling is not supported in this version. P-RES: trace sporadic wake-ups P-RES: use inferred_sporadic_job_release_at() porting fix: add missing header for module_init() porting fix: adopt new hrtimer API in P-RES plugin P-RES: add fork() support P-RES: don't return -ESRCH on reservation lookup failure P-RES: improve task admission - Deal with the fact that task_cpu() is not yet updated for currently suspended tasks. - Provide some feedback via printk().
uncachedev: mmap memory that is not cached by CPUs This patch creates a new character device, uncachedev. Pages of RAM allocated by this device are not cached by CPUs. Uses for such pages: 1) Determining *very* pessimistic emperical worst- case execution times. 2) Compare against performance with caches (quantify the avg. case benefit). 3) Deterministic memory accesses (access cannot cause a cache eviction.) 4) Theoretically, increased performance can be achieved by storing infrequently accessed data in uncache pages. uncachedev allocates pages with the pgprot_noncached() page attribute for user applications. Since pages allocated by uncachedev are not locked in memory by default, applications with any access level may mmap pages with uncachedev. Limitations: 1) Uncache pages must be MAP_PRIVATE. 2) Remapping not supported. Usage (user level): int size = NR_PAGES*PAGE_SIZE; int fd = open("/dev/litmus/uncache", O_RDWR); char *data = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); <...do stuff...> munmap(data, size);
New Feature: Arbitrary deadlines. Added support for arbitrary deadlines. Constraint: Relative deadline must be >= exec cost. Use: Set relative deadline in rt_task::rdeadline. Set value to 0 to default to implicit deadlines. Limitations: PFAIR not supported by this patch. PFAIR updated to reject tasks that do not have implicit deadlines.
Feather-Trace: keep track of interrupt-related interference. Increment a processor-local counter whenever an interrupt is handled. This allows Feather-Trace to include a (truncated) counter and a flag to report interference from interrupts. This could be used to filter samples that were disturbed by interrupts.