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 --- net/ethtool/module_fw.h | 75 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100644 net/ethtool/module_fw.h (limited to 'net/ethtool/module_fw.h') diff --git a/net/ethtool/module_fw.h b/net/ethtool/module_fw.h new file mode 100644 index 000000000..634543a12 --- /dev/null +++ b/net/ethtool/module_fw.h @@ -0,0 +1,75 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include +#include "netlink.h" + +/** + * struct ethnl_module_fw_flash_ntf_params - module firmware flashing + * notifications parameters + * @portid: Netlink portid of sender. + * @seq: Sequence number of sender. + * @closed_sock: Indicates whether the socket was closed from user space. + */ +struct ethnl_module_fw_flash_ntf_params { + u32 portid; + u32 seq; + bool closed_sock; +}; + +/** + * struct ethtool_module_fw_flash_params - module firmware flashing parameters + * @password: Module password. Only valid when @pass_valid is set. + * @password_valid: Whether the module password is valid or not. + */ +struct ethtool_module_fw_flash_params { + __be32 password; + u8 password_valid:1; +}; + +/** + * struct ethtool_cmis_fw_update_params - CMIS firmware update specific + * parameters + * @dev: Pointer to the net_device to be flashed. + * @params: Module firmware flashing parameters. + * @ntf_params: Module firmware flashing notification parameters. + * @fw: Firmware to flash. + */ +struct ethtool_cmis_fw_update_params { + struct net_device *dev; + struct ethtool_module_fw_flash_params params; + struct ethnl_module_fw_flash_ntf_params ntf_params; + const struct firmware *fw; +}; + +/** + * struct ethtool_module_fw_flash - module firmware flashing + * @list: List node for &module_fw_flash_work_list. + * @dev_tracker: Refcount tracker for @dev. + * @work: The flashing firmware work. + * @fw_update: CMIS firmware update specific parameters. + */ +struct ethtool_module_fw_flash { + struct list_head list; + netdevice_tracker dev_tracker; + struct work_struct work; + struct ethtool_cmis_fw_update_params fw_update; +}; + +void ethnl_module_fw_flash_sock_destroy(struct ethnl_sock_priv *sk_priv); + +void +ethnl_module_fw_flash_ntf_err(struct net_device *dev, + struct ethnl_module_fw_flash_ntf_params *params, + char *err_msg, char *sub_err_msg); +void +ethnl_module_fw_flash_ntf_start(struct net_device *dev, + struct ethnl_module_fw_flash_ntf_params *params); +void +ethnl_module_fw_flash_ntf_complete(struct net_device *dev, + struct ethnl_module_fw_flash_ntf_params *params); +void +ethnl_module_fw_flash_ntf_in_progress(struct net_device *dev, + struct ethnl_module_fw_flash_ntf_params *params, + u64 done, u64 total); + +void ethtool_cmis_fw_update(struct ethtool_cmis_fw_update_params *params); -- cgit v1.3.1