# udev rules specific to RHEL-RT Realtime kernel

# insure /dev/rtc points to /dev/rtc0

# we use PROGRAM rather than SYMLINK because there is

# a (good) possibility that a /dev/rtc device file

# already exists and we want to replace it (hence the

# ln -sf)

KERNEL=="rtc0", PROGRAM+="/bin/ln -sf rtc0 /dev/rtc"

# Give permission to the realtime group to write a zero to /dev/cpu_dma_latency

# This will tell the power management system not to transition to a high cstate

KERNEL=="cpu_dma_latency", GROUP="realtime"

# Give permission to the realtime group to read the per cpu msr and cpuid

# registers. This is needed by cyclictest in rt-tests when using the new

# feature to read the smi counters. This is necessary but not sufficient

# A program that wants to access these registers will also need CAP_SYS_RAWIO

SUBSYSTEM=="msr", GROUP="realtime", MODE="0640"

SUBSYSTEM=="cpuid", GROUP="realtime", MODE="0640"