For certain speculative events on Power7, 'perf stat' reports far higher
event count than 'perf record' for the same event.
As described in following commit, a performance monitor exception is raised
even when the the performance events are rolled back.
commit 0837e3242c
Author: Anton Blanchard <anton@samba.org>
Date: Wed Mar 9 14:38:42 2011 +1100
perf_event_interrupt() records an event only when an overflow occurs. But
this check for overflow is a simple 'if (val < 0)'.
Because the events are rolled back, this check for overflow fails and the
event is not recorded. perf_event_interrupt() later uses pmc_overflow() to
detect the overflow and resets the counters and the events are lost completely.
To properly detect the overflow of rolled back events, use pmc_overflow()
even when recording events.
To reproduce:
$ cat strcpy.c
#include <stdio.h>
#include <string.h>
main()
{
char buf[256];
alarm(5);
while(1)
strcpy(buf, "string1");
}
$ perf record -e r20014 ./strcpy
$ perf report -n > report.1
$ perf stat -e r20014 > report.2
# Compare report.1 and report.2
Reported-by: Maynard Johnson <mpjohn@us.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The enhanced prefetch hint patches corrupt the condition register
that was used to check if we are in interrupt. Fix this by using cr1.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
"powerpc: Use enhanced touch instructions in POWER7
copy_to_user/copy_from_user" was applied twice. Remove one.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Directly comparing current->personality against PER_LINUX32 doesn't work
in cases when any of the personality flags stored in the top three bytes
are used.
Directly forcefully setting personality to PER_LINUX32 or PER_LINUX
discards any flags stored in the top three bytes
Use personality() macro to compare only PER_MASK bytes and make sure that
we are setting only the bits that should be set, instead of overwriting
the whole value.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Checking for device mask to cover the whole IOMMU table is too strict.
IOMMU allocators should handle mask constraint properly for each
allocation.
The patch enables to use old AirPort Extreme cards on PowerMacs with
more than 1GB of memory; without the patch the driver init fails with:
b43-pci-bridge 0001:01:01.0: Warning: IOMMU window too big for device mask
b43-pci-bridge 0001:01:01.0: mask: 0x3fffffff, table end: 0x80000000
b43-phy0 ERROR: The machine/kernel does not support the required 30-bit DMA mask
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
For powerpc BooKE and e200, singlestep is handled on the critical/dbg
exception stack. This causes current_thread_info() to fail for kgdb
internal, so previously We work around this issue by copying
the thread_info from the kernel stack before calling kgdb_handle_exception,
and copying it back afterwards.
But actually we don't do this properly. We should backup current_thread_info
then restore that when exit.
Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We need to skip a breakpoint exception when it occurs after
a breakpoint has already been removed.
Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The kgdb_single_step flag has the possibility to indefinitely
hang the system on an SMP system.
The x86 arch have the same problem, and that problem was fixed by
commit 8097551d9ab9b9e3630(kgdb,x86: do not set kgdb_single_step
on x86). This patch does the same behaviors as x86's patch.
Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Currently if you are doing a global perf recording with hardware
breakpoints (ie perf record -e mem:0xdeadbeef -a), you can oops with:
Faulting instruction address: 0xc000000000738890
cpu 0xc: Vector: 300 (Data Access) at [c0000003f76af8d0]
pc: c000000000738890: .hw_breakpoint_handler+0xa0/0x1e0
lr: c000000000738830: .hw_breakpoint_handler+0x40/0x1e0
sp: c0000003f76afb50
msr: 8000000000001032
dar: 6f0
dsisr: 42000000
current = 0xc0000003f765ac00
paca = 0xc00000000f262a00 softe: 0 irq_happened: 0x01
pid = 6810, comm = loop-read
enter ? for help
[c0000003f76afbe0] c00000000073cd04 .notifier_call_chain.isra.0+0x84/0xe0
[c0000003f76afc80] c00000000073cdbc .notify_die+0x3c/0x60
[c0000003f76afd20] c0000000000139f0 .do_dabr+0x40/0xf0
[c0000003f76afe30] c000000000005a9c handle_dabr_fault+0x14/0x48
--- Exception: 300 (Data Access) at 0000000010000480
SP (ff8679e0) is in userspace
This is because we don't check to see if the break point is associated
with task before we deference the task_struct pointer.
This changes the update to use current.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
There are a few whitespace goolies in xmon.c, some of them appear to
be my fault. Fix them all in one go.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Since the printk internals were reworked the xmon 'dl' command which
dumps the content of __log_buf has stopped working.
It is now a structured buffer, so just dumping it doesn't really work.
Use the helpers added for kgdb to print out the content.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The current layout is to place the per-process tables at the end of the
GTT. However, this is currently using a hardcoded maximum size for the GTT
and not taking in account limitations imposed by the BIOS. Use the value
for the total number of entries allocated in the table as provided by
the configuration registers.
Reported-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Matthew Garret <mjg@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Pull crypto fixes from Herbert Xu:
"This push fixes a build error on 32-bit archs in the hifn driver as
well as a potential deadlock in the caam driver."
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: caam - fix possible deadlock condition
crypto: hifn_795x - fix 64bit division and undefined __divdi3 on 32bit archs
Pull UDF, ext3 & reiserfs fixes from Jan Kara:
"A couple of fixes (udf, reiserfs, ext3) that accumulated over my
vacation."
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
udf: fix retun value on error path in udf_load_logicalvol
jbd: don't write superblock when unmounting an ro filesystem
reiserfs: fix deadlocks with quotas
quota: Move down dqptr_sem read after initializing default warn[] type at __dquot_alloc_space().
UDF: During mount free lvid_bh before rescanning with different blocksize
udf: fix udf_setsize() for file data in ICB
Pull IDE power management bugfix from David S. Miller.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide:
ide: fix generic_ide_suspend/resume Oops
Pull x86 fixes from Ingo Molnar:
"This tree contains assorted fixlets: an alternatives patching crash
fix, an irq migration/hotplug interaction fix, a fix for large AMD
microcode images and a comment fixlet."
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, microcode, AMD: Fix broken ucode patch size check
x86/alternatives: Fix p6 nops on non-modular kernels
x86/fixup_irq: Use cpu_online_mask instead of cpu_all_mask
x86/spinlocks: Fix comment in spinlock.h
Pull timer fixes from Thomas Gleixner:
"Mostly small fixes for the fallout of the timekeeping overhaul in 3.6
along with stable fixes to address an accumulation problem and missing
sanity checks for RTC readouts and user space provided values."
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
time: Avoid making adjustments if we haven't accumulated anything
time: Avoid potential shift overflow with large shift values
time: Fix casting issue in timekeeping_forward_now
time: Ensure we normalize the timekeeper in tk_xtime_add
time: Improve sanity checking of timekeeping inputs
Pull HID fix from Jiri Kosina:
"Fix for one particular device not being properly claimed by
hid-multitouch driver"
* 'upstream-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
HID: Remove QUANTA from special drivers list
DRM_MODE() macro doesn't initialize the type of the base drm object.
When a copy is made of the mode, the object type is overwritten with
zero, and the the object can no longer be found by
drm_mode_object_find() due to the type check failing.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
If range.start or range.minlen is bigger than filesystem size, return
invalid value error. This fixes possible overflow in BTOBB macro when
passed value was nearly ULLONG_MAX.
Signed-off-by: Tomas Racek <tracek@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
Sukadev Bhattiprolu
Anton Blanchard
Jiri Kosina
Aaro Koskinen
Michael Neuling
Tiejun Chen
Scott Wood
Michael Ellerman
Chris Wilson
Linus Torvalds
Jakob Bornecrantz
Ville Syrjälä
Tomas Racek