diff options
author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2011-06-27 08:41:57 -0400 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2011-07-01 05:06:35 -0400 |
commit | a8b0ca17b80e92faab46ee7179ba9e99ccb61233 (patch) | |
tree | a4a6282139f26458f80dcbe21c709a9290e84143 /samples/hw_breakpoint | |
parent | 1880c4ae182afb5650c5678949ecfe7ff66a724e (diff) |
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>
Diffstat (limited to 'samples/hw_breakpoint')
-rw-r--r-- | samples/hw_breakpoint/data_breakpoint.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/samples/hw_breakpoint/data_breakpoint.c b/samples/hw_breakpoint/data_breakpoint.c index 063653955f9f..7b164d3200ff 100644 --- a/samples/hw_breakpoint/data_breakpoint.c +++ b/samples/hw_breakpoint/data_breakpoint.c | |||
@@ -41,7 +41,7 @@ module_param_string(ksym, ksym_name, KSYM_NAME_LEN, S_IRUGO); | |||
41 | MODULE_PARM_DESC(ksym, "Kernel symbol to monitor; this module will report any" | 41 | MODULE_PARM_DESC(ksym, "Kernel symbol to monitor; this module will report any" |
42 | " write operations on the kernel symbol"); | 42 | " write operations on the kernel symbol"); |
43 | 43 | ||
44 | static void sample_hbp_handler(struct perf_event *bp, int nmi, | 44 | static void sample_hbp_handler(struct perf_event *bp, |
45 | struct perf_sample_data *data, | 45 | struct perf_sample_data *data, |
46 | struct pt_regs *regs) | 46 | struct pt_regs *regs) |
47 | { | 47 | { |