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 --- Documentation/doc-guide/checktransupdate.rst | 54 ++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 Documentation/doc-guide/checktransupdate.rst (limited to 'Documentation/doc-guide/checktransupdate.rst') diff --git a/Documentation/doc-guide/checktransupdate.rst b/Documentation/doc-guide/checktransupdate.rst new file mode 100644 index 000000000..7b25375cc --- /dev/null +++ b/Documentation/doc-guide/checktransupdate.rst @@ -0,0 +1,54 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Checking for needed translation updates +======================================= + +This script helps track the translation status of the documentation in +different locales, i.e., whether the documentation is up-to-date with +the English counterpart. + +How it works +------------ + +It uses ``git log`` command to track the latest English commit from the +translation commit (order by author date) and the latest English commits +from HEAD. If any differences occur, the file is considered as out-of-date, +then commits that need to be updated will be collected and reported. + +Features implemented + +- check all files in a certain locale +- check a single file or a set of files +- provide options to change output format +- track the translation status of files that have no translation + +Usage +----- + +:: + + tools/docs/checktransupdate.py --help + +Please refer to the output of argument parser for usage details. + +Samples + +- ``tools/docs/checktransupdate.py -l zh_CN`` + This will print all the files that need to be updated in the zh_CN locale. +- ``tools/docs/checktransupdate.py Documentation/translations/zh_CN/dev-tools/testing-overview.rst`` + This will only print the status of the specified file. + +Then the output is something like: + +:: + + Documentation/dev-tools/kfence.rst + No translation in the locale of zh_CN + + Documentation/translations/zh_CN/dev-tools/testing-overview.rst + commit 42fb9cfd5b18 ("Documentation: dev-tools: Add link to RV docs") + 1 commits needs resolving in total + +Features to be implemented + +- files can be a folder instead of only a file -- cgit v1.3.1