[PATCH] paravirt: Add option to allow skipping the timer check

Add a way to disable the timer IRQ routing check via a boot option.  The
VMI timer code uses this to avoid triggering the pester Mingo code, which
probes for some very unusual and broken motherboard routings.  It fires
100% of the time when using a paravirtual delay mechanism instead of using
a realtime delay, since there is no elapsed real time, and the 4 timer IRQs
have not yet been delivered.

In addition, it is entirely possible, though improbable, that this bug
could surface on real hardware which picks a particularly bad time to enter
SMM mode, causing a long latency during one of the timer IRQs.

While here, make check_timer be __init.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andi Kleen <ak@suse.de>
[chrisw: use no_timer_check to bring inline with x86_64 as per Andi's request]
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
This commit is contained in:
Zachary Amsden
2006-12-07 02:14:09 +01:00
committed by Andi Kleen
parent 8ecb895069
commit 8542b200cb
2 changed files with 19 additions and 4 deletions

View File

@ -599,8 +599,6 @@ and is between 256 and 4096 characters. It is defined in the file
hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing
i8042.direct [HW] Put keyboard port into non-translated mode
i8042.dumbkbd [HW] Pretend that controller can only read data from
keyboard and cannot control its state
@ -1052,9 +1050,14 @@ and is between 256 and 4096 characters. It is defined in the file
in certain environments such as networked servers or
real-time systems.
noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing
noirqdebug [IA-32] Disables the code which attempts to detect and
disable unhandled interrupt sources.
no_timer_check [IA-32,X86_64,APIC] Disables the code which tests for
broken timer IRQ sources.
noisapnp [ISAPNP] Disables ISA PnP code.
noinitrd [RAM] Tells the kernel not to load any configured