kernel-hacking-2024-linux-s.../arch/sparc
Peter Zijlstra a8b0ca17b8 perf: Remove the nmi parameter from the swevent and overflow interface
The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.

For the various event classes:

  - hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
    the PMI-tail (ARM etc.)
  - tracepoint: nmi=0; since tracepoint could be from NMI context.
  - software: nmi=[0,1]; some, like the schedule thing cannot
    perform wakeups, and hence need 0.

As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).

The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-01 11:06:35 +02:00
..
boot sparc32: added U-Boot build target: uImage 2011-03-16 18:19:04 -07:00
configs
include/asm Fix node_start/end_pfn() definition for mm/page_cgroup.c 2011-06-27 14:13:09 -07:00
kernel perf: Remove the nmi parameter from the swevent and overflow interface 2011-07-01 11:06:35 +02:00
lib Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6 2011-05-20 12:59:54 -07:00
math-emu perf: Remove the nmi parameter from the swevent and overflow interface 2011-07-01 11:06:35 +02:00
mm perf: Remove the nmi parameter from the swevent and overflow interface 2011-07-01 11:06:35 +02:00
oprofile
prom sparc: Remove unnecessary semicolons 2011-06-07 16:06:34 -07:00
Kconfig sparc: PCIC_PCI needs SPARC32 dependency 2011-06-02 22:49:11 -07:00
Kconfig.debug lib: consolidate DEBUG_STACK_USAGE option 2011-05-25 08:39:54 -07:00
Makefile sparc32: added U-Boot build target: uImage 2011-03-16 18:19:04 -07:00