linux/arch/x86
David Ahern a706d965dc perf x86: revert 20b279 - require exclude_guest to use PEBS - kernel side
This patch is brought to you by the letter 'H'.

Commit 20b279 breaks compatiblity with older perf binaries when run with
precise modifier (:p or :pp) by requiring the exclude_guest attribute to be
set. Older binaries default exclude_guest to 0 (ie., wanting guest-based
samples) unless host only profiling is requested (:H modifier). The workaround
for older binaries is to add H to the modifier list (e.g., -e cycles:ppH -
toggles exclude_guest to 1). This was deemed unacceptable by Linus:

https://lkml.org/lkml/2012/12/12/570

Between family in town and the fresh snow in Breckenridge there is no time left
to be working on the proper fix for this over the holidays. In the New Year I
have more pressing problems to resolve -- like some memory leaks in perf which
are proving to be elusive -- although the aforementioned snow is probably why
they are proving to be elusive. Either way I do not have any spare time to work
on this and from the time I have managed to spend on it the solution is more
difficult than just moving to a new exclude_guest flag (does not work) or
flipping the logic to include_guest (which is not as trivial as one would
think).

So, two options: silently force exclude_guest on as suggested by Gleb which
means no impact to older perf binaries or revert the original patch which
caused the breakage.

This patch does the latter -- reverts the original patch that introduced the
regression. The problem can be revisited in the future as time allows.

Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <robert.richter@amd.com>
Link: http://lkml.kernel.org/r/1356749767-17322-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-01-10 09:21:19 -03:00
..
boot PCI changes for the v3.8 merge window: 2012-12-13 12:14:47 -08:00
configs x86/Kconfig: Turn off DEBUG_NX_TEST module in defconfigs 2012-09-05 10:43:12 +02:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2012-12-15 12:35:19 -08:00
ia32 new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to those 2012-12-19 18:07:41 -05:00
include X86: drivers: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
kernel perf x86: revert 20b279 - require exclude_guest to use PEBS - kernel side 2013-01-10 09:21:19 -03:00
kvm Merge tag 'kvm-3.8-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-12-13 15:31:08 -08:00
lguest x86, MCA: Finish mca_config conversion 2012-10-26 14:37:58 +02:00
lib X86: drivers: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
math-emu
mm Automatic NUMA Balancing V11 2012-12-16 15:18:08 -08:00
net x86: bpf_jit_comp: add vlan tag support 2012-10-31 14:00:15 -04:00
oprofile oprofile, x86: Fix wrapping bug in op_x86_get_ctrl() 2012-10-15 14:38:24 +02:00
pci X86: drivers: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
platform X86: drivers: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
power x86, topology: Debug CPU0 hotplug 2012-11-14 15:28:11 -08:00
realmode Revert "x86, mm: Include the entire kernel memory map in trampoline_pgd" 2012-12-15 12:29:54 -08:00
syscalls Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-12-20 18:05:28 -08:00
tools x86: Fix the error of using "const" in gen-insn-attr-x86.awk 2012-12-10 10:31:24 -08:00
um Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-12-20 18:05:28 -08:00
vdso Merge tag 'kvm-3.8-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-12-13 15:31:08 -08:00
video
xen Bugfixes: 2012-12-18 12:26:54 -08:00
.gitignore
Kbuild x86, realmode: realmode.bin infrastructure 2012-05-08 11:41:48 -07:00
Kconfig Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-12-20 18:05:28 -08:00
Kconfig.cpu x86, 386 removal: Document Nx586 as a 386 and thus unsupported 2012-11-29 13:28:39 -08:00
Kconfig.debug x86/tlb: add tlb_flushall_shift knob into debugfs 2012-06-27 19:29:10 -07:00
Makefile md update for 3.8 2012-12-18 09:32:44 -08:00
Makefile_32.cpu x86, 386 removal: Remove CONFIG_M386 from Kconfig 2012-11-29 13:23:01 -08:00
Makefile.um