The patch titled arch/x86/kernel/acpi/cstate.c: avoid using work_on_cpu() has been added to the -mm tree. Its filename is arch-x86-kernel-acpi-cstatec-avoid-using-work_on_cpu.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: arch/x86/kernel/acpi/cstate.c: avoid using work_on_cpu() From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> A series of patches which - removes all but one callers of work_on_cpu() by switching then to smp_call_function_single() - converts work_on_cpu() to create a kernel thread on depend, thus avoidin the various deadlock scenarios which we keep on experiencing and thinking up. All cheerfully untested. This patch: Atttempting to rid us of the problematic work_on_cpu(). Just use smp_call_fuction_single() here. Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx> Cc: Len Brown <len.brown@xxxxxxxxx> Cc: Zhao Yakui <yakui.zhao@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/acpi/cstate.c | 36 +++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 12 deletions(-) diff -puN arch/x86/kernel/acpi/cstate.c~arch-x86-kernel-acpi-cstatec-avoid-using-work_on_cpu arch/x86/kernel/acpi/cstate.c --- a/arch/x86/kernel/acpi/cstate.c~arch-x86-kernel-acpi-cstatec-avoid-using-work_on_cpu +++ a/arch/x86/kernel/acpi/cstate.c @@ -61,6 +61,12 @@ struct cstate_entry { }; static struct cstate_entry *cpu_cstate_entry; /* per CPU ptr */ +/* Used for the cross-CPU calls */ +struct acpi_processor_cx_cross_cpu { + struct acpi_processor_cx *cx; + long retval; +}; + static short mwait_supported[ACPI_PROCESSOR_MAX_POWER]; #define MWAIT_SUBSTATE_MASK (0xf) @@ -75,10 +81,10 @@ static short mwait_supported[ACPI_PROCES #define NATIVE_CSTATE_BEYOND_HALT (2) -static long acpi_processor_ffh_cstate_probe_cpu(void *_cx) +static void acpi_processor_ffh_cstate_probe_cpu(void *_cxcc) { - struct acpi_processor_cx *cx = _cx; - long retval; + struct acpi_processor_cx_cross_cpu *cxcc = _cxcc; + struct acpi_processor_cx *cx = cxcc->cx; unsigned int eax, ebx, ecx, edx; unsigned int edx_part; unsigned int cstate_type; /* C-state type and not ACPI C-state type */ @@ -92,16 +98,16 @@ static long acpi_processor_ffh_cstate_pr edx_part = edx >> (cstate_type * MWAIT_SUBSTATE_SIZE); num_cstate_subtype = edx_part & MWAIT_SUBSTATE_MASK; - retval = 0; + cxcc->retval = 0; if (num_cstate_subtype < (cx->address & MWAIT_SUBSTATE_MASK)) { - retval = -1; + cxcc->retval = -1; goto out; } /* mwait ecx extensions INTERRUPT_BREAK should be supported for C2/C3 */ if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) || !(ecx & CPUID5_ECX_INTERRUPT_BREAK)) { - retval = -1; + cxcc->retval = -1; goto out; } @@ -115,7 +121,7 @@ static long acpi_processor_ffh_cstate_pr ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x", cx->address); out: - return retval; + return; } int acpi_processor_ffh_cstate_probe(unsigned int cpu, @@ -123,6 +129,7 @@ int acpi_processor_ffh_cstate_probe(unsi { struct cstate_entry *percpu_entry; struct cpuinfo_x86 *c = &cpu_data(cpu); + struct acpi_processor_cx_cross_cpu cxcc = { .cx = cx, }; long retval; if (!cpu_cstate_entry || c->cpuid_level < CPUID_MWAIT_LEAF) @@ -135,13 +142,18 @@ int acpi_processor_ffh_cstate_probe(unsi percpu_entry->states[cx->index].eax = 0; percpu_entry->states[cx->index].ecx = 0; - /* Make sure we are running on right CPU */ + /* Run acpi_processor_ffh_cstate_probe_cpu() on the target CPU */ - retval = work_on_cpu(cpu, acpi_processor_ffh_cstate_probe_cpu, cx); + retval = smp_call_function_single(cpu, + acpi_processor_ffh_cstate_probe_cpu, cx, 1); if (retval == 0) { - /* Use the hint in CST */ - percpu_entry->states[cx->index].eax = cx->address; - percpu_entry->states[cx->index].ecx = MWAIT_ECX_INTERRUPT_BREAK; + retval = cxcc.retval; + if (retval == 0) { + /* Use the hint in CST */ + percpu_entry->states[cx->index].eax = cx->address; + percpu_entry->states[cx->index].ecx = + MWAIT_ECX_INTERRUPT_BREAK; + } } return retval; } _ Patches currently in -mm which might be from akpm@xxxxxxxxxxxxxxxxxxxx are origin.patch kernel-asyncc-fix-printk-warnings.patch revert-rlimit-permit-setting-rlimit_nofile-to-rlim_infinity.patch hp-wmi-fix-error-path-in-hp_wmi_bios_setup.patch wait-prevent-exclusive-waiter-starvation-checkpatch-fixes.patch i-need-old-gcc.patch linux-next.patch next-remove-localversion.patch kvm-unbork.patch fix-sparseirq-use-kstat_irqs_cpu-on-non-x86-architectures-too.patch thinkpad-acpi-split-delayed-leds-stuff-clean-up-code-checkpatch-fixes.patch x86-define-arch_want_frame_pointers-fix.patch kernel-auditscc-fix-warning.patch drivers-consolidate-driver_probe_done-loops-into-one-place-fix.patch drivers-consolidate-driver_probe_done-loops-into-one-place-checkpatch-fixes.patch sysfs-reference-sysfs_dirent-from-sysfs-inodes-fix.patch early-platform-driver-v3-checkpatch-fixes.patch clocksource-pass-clocksource-to-read-callback.patch input-bcm5974-declare-alignment-usage-checkpatch-fixes.patch mtd-rbtx4939-add-mtd-support-fix.patch pci-quirks-unhide-overflow-device-on-i828675p-pe-chipsets.patch raw-fix-rawctl-compat-ioctls-breakage-on-amd64-and-itanic.patch scsi-dpt_i2o-is-bust-on-ia64.patch drivers-ata-sata_silc-needs-dmih.patch net-dont-use-in_atomic-in-gfp_any.patch documentation-connector-cn_testc-dont-use-gfp_any.patch nommu-fix-a-number-of-issues-with-the-per-mm-vma-patch.patch page_fault-retry-with-nopage_retry.patch page_fault-retry-with-nopage_retry-fix.patch page_fault-retry-with-nopage_retry-fix-fix.patch mm-add-proc-controls-for-pdflush-threads-fix.patch mm-add-proc-controls-for-pdflush-threads-fix-fix.patch mm-unify-some-pmd_-functions-fix-s390.patch proc-pid-maps-dont-show-pgoff-of-pure-anon-vmas-checkpatch-fixes.patch do_pipe-drop-its-last-user-in-arch-alpha-checkpatch-fixes.patch epoll-keyed-wakeups-v2-teach-epoll-about-hints-coming-with-the-wakeup-key-checkpatch-fixes.patch rtc-convert-leap_year-into-an-inline.patch rtc-add-platform-driver-for-efi-fix.patch drivers-video-uvesafbc-dont-use-gfp_any.patch cpuset-fix-allocating-page-cache-slab-object-on-the-unallowed-node-when-memory-spread-is-set.patch cpuset-fix-allocating-page-cache-slab-object-on-the-unallowed-node-when-memory-spread-is-set-fix-2.patch pids-document-task_pgrp-task_session-is-not-safe-without-tasklist-rcu-fix.patch nbd-add-locking-to-nbd_ioctl-checkpatch-fixes.patch kexec-add-dmesg-log-symbols-to-proc-vmcoreinfo-lists-fix.patch kexec-add-dmesg-log-symbols-to-proc-vmcoreinfo-lists-fix-fix.patch arch-x86-kernel-acpi-cstatec-avoid-using-work_on_cpu.patch arch-x86-kernel-cpu-cpufreq-acpi-cpufreqc-avoid-using-work_on_cpu.patch arch-x86-kernel-cpu-mcheck-mce_amd_64c-avoid-using-work_on_cpu.patch work_on_cpu-rewrite-it-to-create-a-kernel-thread-on-demand.patch nilfs2-integrated-block-mapping-remove-nilfs-bmap-wrapper-macros-checkpatch-fixes.patch nilfs2-inode-operations-fix.patch nilfs2-pathname-operations-fix.patch nilfs2-super-block-operations-fix.patch reiser4.patch reiser4-remove-simple_prepare_write-usage-checkpatch-fixes.patch slab-leaks3-default-y.patch put_bh-debug.patch shrink_slab-handle-bad-shrinkers.patch getblk-handle-2tb-devices.patch getblk-handle-2tb-devices-fix.patch undeprecate-pci_find_device.patch notify_change-callers-must-hold-i_mutex.patch drivers-net-bonding-bond_sysfsc-suppress-uninitialized-var-warning.patch w1-build-fix.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html