Issue #2652 has been updated by davshao.
Here's what I have determined using kprintf's. The hang occurs in xpt_init() which is called by cam_module_event_handler() on MOD_LOAD in sys/bus/cam/cam_xpt.c. The hang occurs at the call to register_swi() call in xpt_init(). The hang occurs at the call to int_moveto_destcpu() in register_int() in sys/kern/kern_intr.c. The Intel Atom N270 has hyper-threading and thus has ncpus == 2. Perhaps it is somewhat an unfortunate accident that SWI_CAMBIO == 195, FIRTS_SOFTINT + 3 forcing the moveto. The hang occurs at the call to lwkt_migratecpu() in int_moveto_destcpu() in sys/kern/kern_intr.c. The hang occurs at the call to lwkt_setcpu_self() in lwkt_migratecpu() in sys/kern/lwkt_thread.c. (td->td_gd != rgd) == 1 (td->td_release != 0) == 0 td_td_flags == 3 The hang occurs at the call to lwkt_switch() in lwkt_setcpu_self() in sys/kern/lwkt_thread.c. ---------------------------------------- Bug #2652: 189a0ff3761b47 ... ix: Implement MSI-X support locks up Lenovo S10 Intel Atom n270 http://bugs.dragonflybsd.org/issues/2652#change-11885 * Author: davshao * Status: New * Priority: Normal * Assignee: * Category: * Target version: ---------------------------------------- For a i386 Lenovo S10 Intel Atom n270 netbook, bisection indicates using 189a0ff3761b47 ... ix: Implement MSI-X support and enable multiple TX rings locks up the machine on booting at the point: ... md0: invalid primary partition table: no magic Math emulator present hptrr: RocketRAID 17xx/2xxx SATA controller driver v1.2 hpt27xx: RocketRAID 27xx controller driver v1.0 (Feb 28 2014 21:38:19) Attached is a full verbose dmesg from the same machine running with master previous to the above commit. The machine only fully boots with acpi disabled using hint.acpi.0.disabled=1, but even with acpi enabled the lockup with the problematic commit occurs sooner than the normal lockup with acpi enabled. "Normally" on this machine booting with acpi halts at acpi0.nexus0.root0 acpi0: <LENOVO CB-01> [tentative] on motherboard ACPI: All ACPI Tables successfully acquired ACPI FADT: SCI testing interrupt mode ... ACPI FADT: SCI testing level/high IOAPIC: irq 9, gsi 9 edge/high -> level/high ---Files-------------------------------- lenovo_s10_dmesg.txt (36.5 KB) -- You have received this notification because you have either subscribed to it, or are involved in it. To change your notification preferences, please click here: http://bugs.dragonflybsd.org/my/account