From 0d6526f82c3cdefcca47f73f5fc08dc6f335eac6 Mon Sep 17 00:00:00 2001 From: Tim Chen Date: Mon, 21 Sep 2026 17:37:22 -0700 Subject: sched/cache: Keep nr_pref_llc_running in the runnable domain, to fix LLC mis-scheduling bug alb_break_llc() decides whether to break LLC preference during active load balance. It does so by testing that every runnable fair task on the source rq prefers its LLC: env->src_rq->nr_pref_llc_running == env->src_rq->cfs.h_nr_runnable But the two counters cover different sets. nr_pref_llc_running is updated in account_llc_enqueue()/account_llc_dequeue(), next to cfs_rq->nr_queued, so it follows queued tasks. h_nr_runnable is updated in set_delayed()/ clear_delayed() and drops delay-dequeued tasks. So under DELAY_DEQUEUE, a preferring task that goes to sleep stays counted in nr_pref_llc_running while h_nr_runnable falls. The equality then breaks, alb_break_llc() returns false, and active balance is free to pull a task off its preferred LLC. Active balance only moves runnable tasks, and this is the only LLC check it consults: once the stopper runs, LBF_ACTIVE_LB skips the per-task test in can_migrate_task(). The runnable set is the one we want. Fix it on the counter side. A task should be counted in nr_pref_llc_running exactly while it is both queued on its preferred LLC (pref_llc_queued) and runnable (!sched_delayed). Define that membership once in task_pref_llc_runnable(), and adjust the counter only through pref_llc_running_inc()/pref_llc_running_dec() from the four sites that change either input: account_llc_enqueue(), account_llc_dequeue(), set_delayed() and clear_delayed(). Gating every update on the same predicate keeps the delay, wake and dequeue paths from double-counting or underflowing; see the comments at those sites for the ordering. nr_llc_running and sd->llc_counts are not touched and stay on queued semantics. Fixes: 714059f79ff0 ("sched/cache: Handle moving single tasks to/from their preferred LLC") Closes: https://lore.kernel.org/lkml/20260827135000.735138-1-zhanxusheng@xiaomi.com/ Reported-by: Zhan Xusheng Suggested-by: Chen Yu Signed-off-by: Tim Chen Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Reviewed-by: Kayra Cizmeci Cc: # v7.2.x Link: https://patch.msgid.link/06af61afedac32e6477f57feb4d658f6c411c3af.1790035273.git.tim.c.chen@linux.intel.com --- drivers/usb/cdns3/cdns3-debug.h | 157 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 157 insertions(+) create mode 100644 drivers/usb/cdns3/cdns3-debug.h (limited to 'drivers/usb/cdns3/cdns3-debug.h') diff --git a/drivers/usb/cdns3/cdns3-debug.h b/drivers/usb/cdns3/cdns3-debug.h new file mode 100644 index 000000000..4618cfe85 --- /dev/null +++ b/drivers/usb/cdns3/cdns3-debug.h @@ -0,0 +1,157 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Cadence USBSS DRD Driver. + * Debug header file. + * + * Copyright (C) 2018-2019 Cadence. + * + * Author: Pawel Laszczak + */ +#ifndef __LINUX_CDNS3_DEBUG +#define __LINUX_CDNS3_DEBUG + +#include "core.h" + +static inline char *cdns3_decode_usb_irq(char *str, + enum usb_device_speed speed, + u32 usb_ists) +{ + int ret; + + ret = sprintf(str, "IRQ %08x = ", usb_ists); + + if (usb_ists & (USB_ISTS_CON2I | USB_ISTS_CONI)) { + ret += sprintf(str + ret, "Connection %s\n", + usb_speed_string(speed)); + } + if (usb_ists & USB_ISTS_DIS2I || usb_ists & USB_ISTS_DISI) + ret += sprintf(str + ret, "Disconnection "); + if (usb_ists & USB_ISTS_L2ENTI) + ret += sprintf(str + ret, "suspended "); + if (usb_ists & USB_ISTS_L1ENTI) + ret += sprintf(str + ret, "L1 enter "); + if (usb_ists & USB_ISTS_L1EXTI) + ret += sprintf(str + ret, "L1 exit "); + if (usb_ists & USB_ISTS_L2ENTI) + ret += sprintf(str + ret, "L2 enter "); + if (usb_ists & USB_ISTS_L2EXTI) + ret += sprintf(str + ret, "L2 exit "); + if (usb_ists & USB_ISTS_U3EXTI) + ret += sprintf(str + ret, "U3 exit "); + if (usb_ists & USB_ISTS_UWRESI) + ret += sprintf(str + ret, "Warm Reset "); + if (usb_ists & USB_ISTS_UHRESI) + ret += sprintf(str + ret, "Hot Reset "); + if (usb_ists & USB_ISTS_U2RESI) + ret += sprintf(str + ret, "Reset"); + + return str; +} + +static inline char *cdns3_decode_ep_irq(char *str, + u32 ep_sts, + const char *ep_name) +{ + int ret; + + ret = sprintf(str, "IRQ for %s: %08x ", ep_name, ep_sts); + + if (ep_sts & EP_STS_SETUP) + ret += sprintf(str + ret, "SETUP "); + if (ep_sts & EP_STS_IOC) + ret += sprintf(str + ret, "IOC "); + if (ep_sts & EP_STS_ISP) + ret += sprintf(str + ret, "ISP "); + if (ep_sts & EP_STS_DESCMIS) + ret += sprintf(str + ret, "DESCMIS "); + if (ep_sts & EP_STS_STREAMR) + ret += sprintf(str + ret, "STREAMR "); + if (ep_sts & EP_STS_MD_EXIT) + ret += sprintf(str + ret, "MD_EXIT "); + if (ep_sts & EP_STS_TRBERR) + ret += sprintf(str + ret, "TRBERR "); + if (ep_sts & EP_STS_NRDY) + ret += sprintf(str + ret, "NRDY "); + if (ep_sts & EP_STS_PRIME) + ret += sprintf(str + ret, "PRIME "); + if (ep_sts & EP_STS_SIDERR) + ret += sprintf(str + ret, "SIDERRT "); + if (ep_sts & EP_STS_OUTSMM) + ret += sprintf(str + ret, "OUTSMM "); + if (ep_sts & EP_STS_ISOERR) + ret += sprintf(str + ret, "ISOERR "); + if (ep_sts & EP_STS_IOT) + ret += sprintf(str + ret, "IOT "); + + return str; +} + +static inline char *cdns3_decode_epx_irq(char *str, + char *ep_name, + u32 ep_sts) +{ + return cdns3_decode_ep_irq(str, ep_sts, ep_name); +} + +static inline char *cdns3_decode_ep0_irq(char *str, + int dir, + u32 ep_sts) +{ + return cdns3_decode_ep_irq(str, ep_sts, + dir ? "ep0IN" : "ep0OUT"); +} + +/** + * Debug a transfer ring. + * + * Prints out all TRBs in the endpoint ring, even those after the Link TRB. + *. + */ +static inline char *cdns3_dbg_ring(struct cdns3_endpoint *priv_ep, char *str) +{ + dma_addr_t addr = priv_ep->trb_pool_dma; + struct cdns3_trb *trb; + int trb_per_sector; + int ret = 0; + int i; + + trb_per_sector = GET_TRBS_PER_SEGMENT(priv_ep->type); + + trb = &priv_ep->trb_pool[priv_ep->dequeue]; + ret += sprintf(str + ret, "\n\t\tRing contents for %s:", priv_ep->name); + + ret += sprintf(str + ret, + "\n\t\tRing deq index: %d, trb: %p (virt), 0x%llx (dma)\n", + priv_ep->dequeue, trb, + (unsigned long long)cdns3_trb_virt_to_dma(priv_ep, trb)); + + trb = &priv_ep->trb_pool[priv_ep->enqueue]; + ret += sprintf(str + ret, + "\t\tRing enq index: %d, trb: %p (virt), 0x%llx (dma)\n", + priv_ep->enqueue, trb, + (unsigned long long)cdns3_trb_virt_to_dma(priv_ep, trb)); + + ret += sprintf(str + ret, + "\t\tfree trbs: %d, CCS=%d, PCS=%d\n", + priv_ep->free_trbs, priv_ep->ccs, priv_ep->pcs); + + if (trb_per_sector > TRBS_PER_SEGMENT) { + sprintf(str + ret, "\t\tTransfer ring %d too big\n", + trb_per_sector); + return str; + } + + for (i = 0; i < trb_per_sector; ++i) { + trb = &priv_ep->trb_pool[i]; + ret += sprintf(str + ret, + "\t\t@%pad %08x %08x %08x\n", &addr, + le32_to_cpu(trb->buffer), + le32_to_cpu(trb->length), + le32_to_cpu(trb->control)); + addr += sizeof(*trb); + } + + return str; +} + +#endif /*__LINUX_CDNS3_DEBUG*/ -- cgit v1.3.1