cpu/resctrl/monitor.c

268  * Supporting function to calculate the memory bandwidth
269  * and delta bandwidth in MBps.
323  * adjust the bandwidth percentage values via the IA32_MBA_THRTL_MSRs so
326  *   current bandwdith(cur_bw) < user specified bandwidth(user_bw)
328  * This uses the MBM counters to measure the bandwidth and MBA throttle
329  * MSRs to control the bandwidth for a particular rdtgrp. It builds on the
333  * timer. Having 1s interval makes the calculation of bandwidth simpler.
335  * Although MBA's goal is to restrict the bandwidth to a maximum, there may
336  * be a need to increase the bandwidth to avoid uncecessarily restricting
339  * Since MBA controls the L2 external bandwidth where as MBM measures the
340  * L3 external bandwidth the following sequence could lead to such a
344  * phases -> mba_sc kicks in and reduced bandwidth percentage values -> but
349  * unnecessarily restricting such rdtgroups, we also increase the bandwidth.
391 	 * Scale up/down the bandwidth linearly for the ctrl group.  The  in update_mba_bw()
392 	 * bandwidth step is the bandwidth granularity specified by the  in update_mba_bw()
395 	 * The delta_bw is used when increasing the bandwidth so that we  in update_mba_bw()
400 	 * bandwidth step is 20MBps(> user_bw - cur_bw), we would keep  in update_mba_bw()
421 	 * This is because (1)the increase in bandwidth is not perfectly  in update_mba_bw()
592  * because as per the SDM the total and local memory bandwidth