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/net/netdevsim/macsec.c | 351 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 351 insertions(+) create mode 100644 drivers/net/netdevsim/macsec.c (limited to 'drivers/net/netdevsim/macsec.c') diff --git a/drivers/net/netdevsim/macsec.c b/drivers/net/netdevsim/macsec.c new file mode 100644 index 000000000..bdc8020d5 --- /dev/null +++ b/drivers/net/netdevsim/macsec.c @@ -0,0 +1,351 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include "netdevsim.h" + +static int nsim_macsec_find_secy(struct netdevsim *ns, sci_t sci) +{ + int i; + + for (i = 0; i < NSIM_MACSEC_MAX_SECY_COUNT; i++) { + if (ns->macsec.nsim_secy[i].sci == sci) + return i; + } + + return -1; +} + +static int nsim_macsec_find_rxsc(struct nsim_secy *ns_secy, sci_t sci) +{ + int i; + + for (i = 0; i < NSIM_MACSEC_MAX_RXSC_COUNT; i++) { + if (ns_secy->nsim_rxsc[i].sci == sci) + return i; + } + + return -1; +} + +static int nsim_macsec_add_secy(struct macsec_context *ctx) +{ + struct netdevsim *ns = netdev_priv(ctx->netdev); + int idx; + + if (ns->macsec.nsim_secy_count == NSIM_MACSEC_MAX_SECY_COUNT) + return -ENOSPC; + + for (idx = 0; idx < NSIM_MACSEC_MAX_SECY_COUNT; idx++) { + if (!ns->macsec.nsim_secy[idx].used) + break; + } + + if (idx == NSIM_MACSEC_MAX_SECY_COUNT) { + netdev_err(ctx->netdev, "%s: nsim_secy_count not full but all SecYs used\n", + __func__); + return -ENOSPC; + } + + netdev_dbg(ctx->netdev, "%s: adding new secy with sci %016llx at index %d\n", + __func__, sci_to_cpu(ctx->secy->sci), idx); + ns->macsec.nsim_secy[idx].used = true; + ns->macsec.nsim_secy[idx].nsim_rxsc_count = 0; + ns->macsec.nsim_secy[idx].sci = ctx->secy->sci; + ns->macsec.nsim_secy_count++; + + return 0; +} + +static int nsim_macsec_upd_secy(struct macsec_context *ctx) +{ + struct netdevsim *ns = netdev_priv(ctx->netdev); + int idx; + + idx = nsim_macsec_find_secy(ns, ctx->secy->sci); + if (idx < 0) { + netdev_err(ctx->netdev, "%s: sci %016llx not found in secy table\n", + __func__, sci_to_cpu(ctx->secy->sci)); + return -ENOENT; + } + + netdev_dbg(ctx->netdev, "%s: updating secy with sci %016llx at index %d\n", + __func__, sci_to_cpu(ctx->secy->sci), idx); + + return 0; +} + +static int nsim_macsec_del_secy(struct macsec_context *ctx) +{ + struct netdevsim *ns = netdev_priv(ctx->netdev); + int idx; + + idx = nsim_macsec_find_secy(ns, ctx->secy->sci); + if (idx < 0) { + netdev_err(ctx->netdev, "%s: sci %016llx not found in secy table\n", + __func__, sci_to_cpu(ctx->secy->sci)); + return -ENOENT; + } + + netdev_dbg(ctx->netdev, "%s: removing SecY with SCI %016llx at index %d\n", + __func__, sci_to_cpu(ctx->secy->sci), idx); + + ns->macsec.nsim_secy[idx].used = false; + memset(&ns->macsec.nsim_secy[idx], 0, sizeof(ns->macsec.nsim_secy[idx])); + ns->macsec.nsim_secy_count--; + + return 0; +} + +static int nsim_macsec_add_rxsc(struct macsec_context *ctx) +{ + struct netdevsim *ns = netdev_priv(ctx->netdev); + struct nsim_secy *secy; + int idx; + + idx = nsim_macsec_find_secy(ns, ctx->secy->sci); + if (idx < 0) { + netdev_err(ctx->netdev, "%s: sci %016llx not found in secy table\n", + __func__, sci_to_cpu(ctx->secy->sci)); + return -ENOENT; + } + secy = &ns->macsec.nsim_secy[idx]; + + if (secy->nsim_rxsc_count == NSIM_MACSEC_MAX_RXSC_COUNT) + return -ENOSPC; + + for (idx = 0; idx < NSIM_MACSEC_MAX_RXSC_COUNT; idx++) { + if (!secy->nsim_rxsc[idx].used) + break; + } + + if (idx == NSIM_MACSEC_MAX_RXSC_COUNT) + netdev_err(ctx->netdev, "%s: nsim_rxsc_count not full but all RXSCs used\n", + __func__); + + netdev_dbg(ctx->netdev, "%s: adding new rxsc with sci %016llx at index %d\n", + __func__, sci_to_cpu(ctx->rx_sc->sci), idx); + secy->nsim_rxsc[idx].used = true; + secy->nsim_rxsc[idx].sci = ctx->rx_sc->sci; + secy->nsim_rxsc_count++; + + return 0; +} + +static int nsim_macsec_upd_rxsc(struct macsec_context *ctx) +{ + struct netdevsim *ns = netdev_priv(ctx->netdev); + struct nsim_secy *secy; + int idx; + + idx = nsim_macsec_find_secy(ns, ctx->secy->sci); + if (idx < 0) { + netdev_err(ctx->netdev, "%s: sci %016llx not found in secy table\n", + __func__, sci_to_cpu(ctx->secy->sci)); + return -ENOENT; + } + secy = &ns->macsec.nsim_secy[idx]; + + idx = nsim_macsec_find_rxsc(secy, ctx->rx_sc->sci); + if (idx < 0) { + netdev_err(ctx->netdev, "%s: sci %016llx not found in RXSC table\n", + __func__, sci_to_cpu(ctx->rx_sc->sci)); + return -ENOENT; + } + + netdev_dbg(ctx->netdev, "%s: updating RXSC with sci %016llx at index %d\n", + __func__, sci_to_cpu(ctx->rx_sc->sci), idx); + + return 0; +} + +static int nsim_macsec_del_rxsc(struct macsec_context *ctx) +{ + struct netdevsim *ns = netdev_priv(ctx->netdev); + struct nsim_secy *secy; + int idx; + + idx = nsim_macsec_find_secy(ns, ctx->secy->sci); + if (idx < 0) { + netdev_err(ctx->netdev, "%s: sci %016llx not found in secy table\n", + __func__, sci_to_cpu(ctx->secy->sci)); + return -ENOENT; + } + secy = &ns->macsec.nsim_secy[idx]; + + idx = nsim_macsec_find_rxsc(secy, ctx->rx_sc->sci); + if (idx < 0) { + netdev_err(ctx->netdev, "%s: sci %016llx not found in RXSC table\n", + __func__, sci_to_cpu(ctx->rx_sc->sci)); + return -ENOENT; + } + + netdev_dbg(ctx->netdev, "%s: removing RXSC with sci %016llx at index %d\n", + __func__, sci_to_cpu(ctx->rx_sc->sci), idx); + + secy->nsim_rxsc[idx].used = false; + memset(&secy->nsim_rxsc[idx], 0, sizeof(secy->nsim_rxsc[idx])); + secy->nsim_rxsc_count--; + + return 0; +} + +static int nsim_macsec_add_rxsa(struct macsec_context *ctx) +{ + struct netdevsim *ns = netdev_priv(ctx->netdev); + struct nsim_secy *secy; + int idx; + + idx = nsim_macsec_find_secy(ns, ctx->secy->sci); + if (idx < 0) { + netdev_err(ctx->netdev, "%s: sci %016llx not found in secy table\n", + __func__, sci_to_cpu(ctx->secy->sci)); + return -ENOENT; + } + secy = &ns->macsec.nsim_secy[idx]; + + idx = nsim_macsec_find_rxsc(secy, ctx->sa.rx_sa->sc->sci); + if (idx < 0) { + netdev_err(ctx->netdev, "%s: sci %016llx not found in RXSC table\n", + __func__, sci_to_cpu(ctx->sa.rx_sa->sc->sci)); + return -ENOENT; + } + + netdev_dbg(ctx->netdev, "%s: RXSC with sci %016llx, AN %u\n", + __func__, sci_to_cpu(ctx->sa.rx_sa->sc->sci), ctx->sa.assoc_num); + + return 0; +} + +static int nsim_macsec_upd_rxsa(struct macsec_context *ctx) +{ + struct netdevsim *ns = netdev_priv(ctx->netdev); + struct nsim_secy *secy; + int idx; + + idx = nsim_macsec_find_secy(ns, ctx->secy->sci); + if (idx < 0) { + netdev_err(ctx->netdev, "%s: sci %016llx not found in secy table\n", + __func__, sci_to_cpu(ctx->secy->sci)); + return -ENOENT; + } + secy = &ns->macsec.nsim_secy[idx]; + + idx = nsim_macsec_find_rxsc(secy, ctx->sa.rx_sa->sc->sci); + if (idx < 0) { + netdev_err(ctx->netdev, "%s: sci %016llx not found in RXSC table\n", + __func__, sci_to_cpu(ctx->sa.rx_sa->sc->sci)); + return -ENOENT; + } + + netdev_dbg(ctx->netdev, "%s: RXSC with sci %016llx, AN %u\n", + __func__, sci_to_cpu(ctx->sa.rx_sa->sc->sci), ctx->sa.assoc_num); + + return 0; +} + +static int nsim_macsec_del_rxsa(struct macsec_context *ctx) +{ + struct netdevsim *ns = netdev_priv(ctx->netdev); + struct nsim_secy *secy; + int idx; + + idx = nsim_macsec_find_secy(ns, ctx->secy->sci); + if (idx < 0) { + netdev_err(ctx->netdev, "%s: sci %016llx not found in secy table\n", + __func__, sci_to_cpu(ctx->secy->sci)); + return -ENOENT; + } + secy = &ns->macsec.nsim_secy[idx]; + + idx = nsim_macsec_find_rxsc(secy, ctx->sa.rx_sa->sc->sci); + if (idx < 0) { + netdev_err(ctx->netdev, "%s: sci %016llx not found in RXSC table\n", + __func__, sci_to_cpu(ctx->sa.rx_sa->sc->sci)); + return -ENOENT; + } + + netdev_dbg(ctx->netdev, "%s: RXSC with sci %016llx, AN %u\n", + __func__, sci_to_cpu(ctx->sa.rx_sa->sc->sci), ctx->sa.assoc_num); + + return 0; +} + +static int nsim_macsec_add_txsa(struct macsec_context *ctx) +{ + struct netdevsim *ns = netdev_priv(ctx->netdev); + int idx; + + idx = nsim_macsec_find_secy(ns, ctx->secy->sci); + if (idx < 0) { + netdev_err(ctx->netdev, "%s: sci %016llx not found in secy table\n", + __func__, sci_to_cpu(ctx->secy->sci)); + return -ENOENT; + } + + netdev_dbg(ctx->netdev, "%s: SECY with sci %016llx, AN %u\n", + __func__, sci_to_cpu(ctx->secy->sci), ctx->sa.assoc_num); + + return 0; +} + +static int nsim_macsec_upd_txsa(struct macsec_context *ctx) +{ + struct netdevsim *ns = netdev_priv(ctx->netdev); + int idx; + + idx = nsim_macsec_find_secy(ns, ctx->secy->sci); + if (idx < 0) { + netdev_err(ctx->netdev, "%s: sci %016llx not found in secy table\n", + __func__, sci_to_cpu(ctx->secy->sci)); + return -ENOENT; + } + + netdev_dbg(ctx->netdev, "%s: SECY with sci %016llx, AN %u\n", + __func__, sci_to_cpu(ctx->secy->sci), ctx->sa.assoc_num); + + return 0; +} + +static int nsim_macsec_del_txsa(struct macsec_context *ctx) +{ + struct netdevsim *ns = netdev_priv(ctx->netdev); + int idx; + + idx = nsim_macsec_find_secy(ns, ctx->secy->sci); + if (idx < 0) { + netdev_err(ctx->netdev, "%s: sci %016llx not found in secy table\n", + __func__, sci_to_cpu(ctx->secy->sci)); + return -ENOENT; + } + + netdev_dbg(ctx->netdev, "%s: SECY with sci %016llx, AN %u\n", + __func__, sci_to_cpu(ctx->secy->sci), ctx->sa.assoc_num); + + return 0; +} + +static const struct macsec_ops nsim_macsec_ops = { + .mdo_add_secy = nsim_macsec_add_secy, + .mdo_upd_secy = nsim_macsec_upd_secy, + .mdo_del_secy = nsim_macsec_del_secy, + .mdo_add_rxsc = nsim_macsec_add_rxsc, + .mdo_upd_rxsc = nsim_macsec_upd_rxsc, + .mdo_del_rxsc = nsim_macsec_del_rxsc, + .mdo_add_rxsa = nsim_macsec_add_rxsa, + .mdo_upd_rxsa = nsim_macsec_upd_rxsa, + .mdo_del_rxsa = nsim_macsec_del_rxsa, + .mdo_add_txsa = nsim_macsec_add_txsa, + .mdo_upd_txsa = nsim_macsec_upd_txsa, + .mdo_del_txsa = nsim_macsec_del_txsa, +}; + +void nsim_macsec_init(struct netdevsim *ns) +{ + ns->netdev->macsec_ops = &nsim_macsec_ops; + ns->netdev->features |= NETIF_F_HW_MACSEC; + memset(&ns->macsec, 0, sizeof(ns->macsec)); +} + +void nsim_macsec_teardown(struct netdevsim *ns) +{ +} -- cgit v1.3.1