litmus-rt.git - The LITMUS^RT kernel.

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author	Andrej Gelenberg <andrej.gelenberg@udo.edu>	2010-05-14 18:15:58 -0400
committer	Dave Jones <davej@redhat.com>	2010-07-26 15:25:33 -0400
commit	accd846698439ba18250e8fd5681af280446b853 (patch)
tree	c76971857ceb6ca4661beee6b4922278a93d91a4 /include/linux/kernel.h
parent	dbbe4649d683577de1063dbd9f6da7d4b8de2fed (diff)

[CPUFREQ] revert "[CPUFREQ] remove rwsem lock from CPUFREQ_GOV_STOP call (second call site)"

395913d0b1db37092ea3d9d69b832183b1dd84c5 ("[CPUFREQ] remove rwsem lock from CPUFREQ_GOV_STOP call (second call site)") is not needed, because there is no rwsem lock in cpufreq_ondemand and cpufreq_conservative anymore. Lock should not be released until the work done. Addresses https://bugzilla.kernel.org/show_bug.cgi?id=1594 Signed-off-by: Andrej Gelenberg <andrej.gelenberg@udo.edu> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Dave Jones <davej@redhat.com>

Diffstat (limited to 'include/linux/kernel.h')

0 files changed, 0 insertions, 0 deletions

#include <sys/mman.h> #include <sys/fcntl.h> /* for O_RDWR */ #include <sys/unistd.h> #include <sched.h> /* for sched_yield() */ #include <stdio.h> #include "litmus.h" #include "internal.h" #include "asm.h" #define LITMUS_CTRL_DEVICE "/dev/litmus/ctrl" #define CTRL_PAGES 1 static int map_file(const char* filename, void **addr, size_t size) { int error = 0; int fd; if (size > 0) { fd = open(filename, O_RDWR); if (fd >= 0) { *addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); if (*addr == MAP_FAILED) error = -1; close(fd); } else error = fd; } else *addr = NULL; return error; } /* thread-local pointer to control page */ static __thread struct control_page *ctrl_page; int init_kernel_iface(void) { int err = 0; long page_size = sysconf(_SC_PAGESIZE); err = map_file(LITMUS_CTRL_DEVICE, (void**) &ctrl_page, CTRL_PAGES * page_size); if (err) { fprintf(stderr, "%s: cannot open LITMUS^RT control page (%m)\n", __FUNCTION__); } return err; } void enter_np(void) { if (likely(ctrl_page != NULL) || init_kernel_iface() == 0) ctrl_page->np_flag++; else fprintf(stderr, "enter_np: control page not mapped!\n"); } void exit_np(void) { if (likely(ctrl_page != NULL) && --ctrl_page->np_flag == 0) { /* became preemptive, let's check for delayed preemptions */ barrier(); if (ctrl_page->delayed_preemption) sched_yield(); } }


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