The branch main has been updated by jtl: URL: https://cgit.FreeBSD.org/src/commit/?id=5e1611a37a02076180ccea1506713b8c9628779e
commit 5e1611a37a02076180ccea1506713b8c9628779e Author: Jonathan T. Looney <[email protected]> AuthorDate: 2025-10-03 18:26:37 +0000 Commit: Jonathan T. Looney <[email protected]> CommitDate: 2025-10-06 16:00:26 +0000 x86: Defer non-fatal MCA message output from the HW interrupt context When processing recoverable MCA events in a hardware interrupt context, defer logging the messages to a task queue. Reviewed by: markj MFC after: 2 weeks Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D12275 --- sys/x86/x86/mca.c | 41 ++++++++++++++++++++++++++++++++++------- 1 file changed, 34 insertions(+), 7 deletions(-) diff --git a/sys/x86/x86/mca.c b/sys/x86/x86/mca.c index 933d10e52187..e43c88b3a27b 100644 --- a/sys/x86/x86/mca.c +++ b/sys/x86/x86/mca.c @@ -131,6 +131,7 @@ static STAILQ_HEAD(, mca_internal) mca_pending; static int mca_ticks = 300; static struct taskqueue *mca_tq; static struct task mca_resize_task; +static struct task mca_postscan_task; static struct timeout_task mca_scan_task; static struct mtx mca_lock; static bool mca_startup_done = false; @@ -1017,6 +1018,16 @@ mca_process_records(enum scan_mode mode) { struct mca_internal *mca; + /* + * If in an interrupt context, defer the post-scan activities to a + * task queue. + */ + if (mode != POLLED) { + if (mca_startup_done) + taskqueue_enqueue(mca_tq, &mca_postscan_task); + return; + } + mtx_lock_spin(&mca_lock); while ((mca = STAILQ_FIRST(&mca_pending)) != NULL) { STAILQ_REMOVE_HEAD(&mca_pending, link); @@ -1024,10 +1035,19 @@ mca_process_records(enum scan_mode mode) mca_store_record(mca); } mtx_unlock_spin(&mca_lock); - if (mode == POLLED) - mca_resize_freelist(); - else if (mca_startup_done) - taskqueue_enqueue(mca_tq, &mca_resize_task); + mca_resize_freelist(); +} + +/* + * Emit log entries and resize the free list. This is intended to be called + * from a task queue to handle work which does not need to be done (or cannot + * be done) in an interrupt context. + */ +static void +mca_postscan(void *context __unused, int pending __unused) +{ + + mca_process_records(POLLED); } /* @@ -1110,13 +1130,16 @@ mca_startup(void *dummy) if (mca_banks <= 0) return; - /* CMCIs during boot may have claimed items from the freelist. */ - mca_resize_freelist(); - taskqueue_start_threads(&mca_tq, 1, PI_SWI(SWI_TQ), "mca taskq"); taskqueue_enqueue_timeout_sbt(mca_tq, &mca_scan_task, mca_ticks * SBT_1S, 0, C_PREL(1)); mca_startup_done = true; + + /* + * CMCIs during boot may have recorded entries. Conduct the post-scan + * activities now. + */ + mca_postscan(NULL, 0); } SYSINIT(mca_startup, SI_SUB_KICK_SCHEDULER, SI_ORDER_ANY, mca_startup, NULL); @@ -1176,6 +1199,7 @@ mca_setup(uint64_t mcg_cap) TIMEOUT_TASK_INIT(mca_tq, &mca_scan_task, 0, mca_scan_cpus, NULL); STAILQ_INIT(&mca_freelist); TASK_INIT(&mca_resize_task, 0, mca_resize, NULL); + TASK_INIT(&mca_postscan_task, 0, mca_postscan, NULL); mca_resize_freelist(); SYSCTL_ADD_INT(NULL, SYSCTL_STATIC_CHILDREN(_hw_mca), OID_AUTO, "count", CTLFLAG_RD, (int *)(uintptr_t)&mca_count, 0, @@ -1579,6 +1603,9 @@ mca_intr(void) panic("Unrecoverable machine check exception"); } + if (count) + mca_process_records(MCE); + /* Clear MCIP. */ wrmsr(MSR_MCG_STATUS, mcg_status & ~MCG_STATUS_MCIP); }
