linux/arch/x86/xen
Konrad Rzeszutek Wilk 466318a87f xen/smp: Fixup NOHZ per cpu data when onlining an offline CPU.
The xen_play_dead is an undead function. When the vCPU is told to
offline it ends up calling xen_play_dead wherin it calls the
VCPUOP_down hypercall which offlines the vCPU. However, when the
vCPU is onlined back, it resumes execution right after
VCPUOP_down hypercall.

That was OK (albeit the API for play_dead assumes that the CPU
stays dead and never returns) but with commit 4b0c0f294
(tick: Cleanup NOHZ per cpu data on cpu down) that is no longer safe
as said commit resets the ts->inidle which at the start of the
cpu_idle loop was set.

The net effect is that we get this warn:

Broke affinity for irq 16
installing Xen timer for CPU 1
cpu 1 spinlock event irq 48
------------[ cut here ]------------
WARNING: at /home/konrad/linux-linus/kernel/time/tick-sched.c:935 tick_nohz_idle_exit+0x195/0x1b0()
Modules linked in: dm_multipath dm_mod xen_evtchn iscsi_boot_sysfs
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.10.0-rc3upstream-00068-gdcdbe33 #1
Hardware name: BIOSTAR Group N61PB-M2S/N61PB-M2S, BIOS 6.00 PG 09/03/2009
 ffffffff8193b448 ffff880039da5e60 ffffffff816707c8 ffff880039da5ea0
 ffffffff8108ce8b ffff880039da4010 ffff88003fa8e500 ffff880039da4010
 0000000000000001 ffff880039da4000 ffff880039da4010 ffff880039da5eb0
Call Trace:
 [<ffffffff816707c8>] dump_stack+0x19/0x1b
 [<ffffffff8108ce8b>] warn_slowpath_common+0x6b/0xa0
 [<ffffffff8108ced5>] warn_slowpath_null+0x15/0x20
 [<ffffffff810e4745>] tick_nohz_idle_exit+0x195/0x1b0
 [<ffffffff810da755>] cpu_startup_entry+0x205/0x250
 [<ffffffff81661070>] cpu_bringup_and_idle+0x13/0x15
---[ end trace 915c8c486004dda1 ]---

b/c ts_inidle is set to zero. Thomas suggested that we just add a workaround
to call tick_nohz_idle_enter before returning from xen_play_dead() - and
that is what this patch does and fixes the issue.

We also add the stable part b/c git commit 4b0c0f294 is on the stable
tree.

CC: stable@vger.kernel.org
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-06-04 09:03:18 -04:00
..
Kconfig x86: Make Linux guest support optional 2013-03-04 13:14:25 -08:00
Makefile xen/x86: Implement x86_apic_ops 2012-05-01 14:50:33 -04:00
apic.c xen/apic/xenbus/swiotlb/pcifront/grant/tmem: Make functions or variables static. 2012-08-21 14:50:03 -04:00
debugfs.c debugfs: Add support to print u32 array in debugfs 2012-04-17 00:18:36 -04:00
debugfs.h debugfs: Add support to print u32 array in debugfs 2012-04-17 00:18:36 -04:00
enlighten.c Bug-fixes: 2013-05-11 16:19:30 -07:00
grant-table.c Merge commit 'v3.2-rc3' into stable/for-linus-3.3 2011-12-20 17:01:18 -05:00
irq.c xen/arm: receive Xen events on ARM 2012-09-14 13:37:32 +00:00
mmu.c Merge branch 'x86-kaslr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-04-30 08:37:24 -07:00
mmu.h xen: make a pile of mmu pvop functions static 2011-05-20 14:25:24 -07:00
multicalls.c xen/multicall: move *idx fields to start of mc_buffer 2011-07-18 15:43:46 -07:00
multicalls.h xen: use this_cpu_xxx replace percpu_xxx funcs 2012-01-24 12:20:24 -05:00
p2m.c Features: 2012-10-02 22:09:10 -07:00
pci-swiotlb-xen.c Merge branch 'stable/late-swiotlb.v3.3' into stable/for-linus-3.7 2012-09-22 20:01:24 -04:00
platform-pci-unplug.c xen/apic/xenbus/swiotlb/pcifront/grant/tmem: Make functions or variables static. 2012-08-21 14:50:03 -04:00
setup.c x86 idle: remove 32-bit-only "no-hlt" parameter, hlt_works_ok flag 2013-02-10 03:32:22 -05:00
smp.c xen/smp: Fixup NOHZ per cpu data when onlining an offline CPU. 2013-06-04 09:03:18 -04:00
smp.h xen: Clean up apic ipi interface 2013-05-29 09:04:21 -04:00
spinlock.c xen/spinlock: Fix check from greater than to be also be greater or equal to. 2013-05-08 08:38:09 -04:00
suspend.c Revert "xen PVonHVM: use E820_Reserved area for shared_info" 2013-02-14 21:29:31 -05:00
time.c xen/time: Add default value of -1 for IRQ and check for that. 2013-04-16 16:05:14 -04:00
trace.c xen/trace: Fix compile error when CONFIG_XEN_PRIVILEGED_GUEST is not set 2011-08-05 09:43:02 -04:00
vdso.h
vga.c xen/vga: add the xen EFI video mode support 2012-09-24 09:28:57 -04:00
xen-asm.S xen: correctly check for pending events when restoring irq flags 2012-04-27 16:04:21 -04:00
xen-asm.h xen: make direct versions of irq_enable/disable/save/restore to common code 2009-02-04 16:59:04 -08:00
xen-asm_32.S x86/xen: don't assume %ds is usable in xen_iret for 32-bit PVOPS. 2013-02-13 15:40:30 -05:00
xen-asm_64.S xen: use iret for return from 64b kernel to 32b usermode 2009-12-03 11:14:54 -08:00
xen-head.S xen/perf: Define .glob for the different hypercalls. 2012-07-30 14:27:48 -04:00
xen-ops.h Revert "xen PVonHVM: use E820_Reserved area for shared_info" 2013-02-14 21:29:31 -05:00