cpu/resctrl/monitor.c

427  * Supporting function to calculate the memory bandwidth
428  * and delta bandwidth in MBps. The chunks value previously read by
488  * adjust the bandwidth percentage values via the IA32_MBA_THRTL_MSRs so
491  *   current bandwidth(cur_bw) < user specified bandwidth(user_bw)
493  * This uses the MBM counters to measure the bandwidth and MBA throttle
494  * MSRs to control the bandwidth for a particular rdtgrp. It builds on the
498  * timer. Having 1s interval makes the calculation of bandwidth simpler.
500  * Although MBA's goal is to restrict the bandwidth to a maximum, there may
501  * be a need to increase the bandwidth to avoid unnecessarily restricting
504  * Since MBA controls the L2 external bandwidth where as MBM measures the
505  * L3 external bandwidth the following sequence could lead to such a
509  * phases -> mba_sc kicks in and reduced bandwidth percentage values -> but
514  * unnecessarily restricting such rdtgroups, we also increase the bandwidth.
557 	 * Scale up/down the bandwidth linearly for the ctrl group.  The  in update_mba_bw()
558 	 * bandwidth step is the bandwidth granularity specified by the  in update_mba_bw()
560 	 * Always increase throttling if current bandwidth is above the  in update_mba_bw()
564 	 * back over target. E.g. if currently throttling to 30% of bandwidth  in update_mba_bw()
566 	 * 40% would go past the limit by multiplying current bandwidth by  in update_mba_bw()
741  * because as per the SDM the total and local memory bandwidth
796 		/* Detect list of bandwidth sources that can be tracked */  in rdt_get_mon_l3_config()