On 10/13/15 3:54 AM, He Kuang wrote:
If we want perf to reflect as soon as our sample event be generated,
--no-buffering should be used, but this option has a greater
impact on performance.
no_buffering doesn't have to be applied to all events obviously.
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On 2015/10/13 18:54, He Kuang wrote:
hi, Alexei
What about using similar
implementation
like PERF_EVENT_IOC_SET_OUTPUT, creating a new ioctl like
PERF_EVENT_IOC_SET_ENABLER,
then let perf to select an event as 'enabler', then BPF can still
control one atomic
variable to enable/disable a set
hi, Alexei
What about using similar
implementation
like PERF_EVENT_IOC_SET_OUTPUT, creating a new ioctl like
PERF_EVENT_IOC_SET_ENABLER,
then let perf to select an event as 'enabler', then BPF can still
control one atomic
variable to enable/disable a set of events.
you lost me on that last
On 2015/10/13 13:15, Alexei Starovoitov wrote:
On 10/12/15 9:34 PM, Wangnan (F) wrote:
On 2015/10/13 12:16, Alexei Starovoitov wrote:
On 10/12/15 8:51 PM, Wangnan (F) wrote:
why 'set disable' is needed ?
the example given in cover letter shows the use case where you want
to receive
On 10/13/15 3:54 AM, He Kuang wrote:
If we want perf to reflect as soon as our sample event be generated,
--no-buffering should be used, but this option has a greater
impact on performance.
no_buffering doesn't have to be applied to all events obviously.
--
To unsubscribe from this list: send
On 2015/10/13 13:15, Alexei Starovoitov wrote:
On 10/12/15 9:34 PM, Wangnan (F) wrote:
On 2015/10/13 12:16, Alexei Starovoitov wrote:
On 10/12/15 8:51 PM, Wangnan (F) wrote:
why 'set disable' is needed ?
the example given in cover letter shows the use case where you want
to receive
hi, Alexei
What about using similar
implementation
like PERF_EVENT_IOC_SET_OUTPUT, creating a new ioctl like
PERF_EVENT_IOC_SET_ENABLER,
then let perf to select an event as 'enabler', then BPF can still
control one atomic
variable to enable/disable a set of events.
you lost me on that last
On 2015/10/13 18:54, He Kuang wrote:
hi, Alexei
What about using similar
implementation
like PERF_EVENT_IOC_SET_OUTPUT, creating a new ioctl like
PERF_EVENT_IOC_SET_ENABLER,
then let perf to select an event as 'enabler', then BPF can still
control one atomic
variable to enable/disable a set
On 10/12/15 9:34 PM, Wangnan (F) wrote:
On 2015/10/13 12:16, Alexei Starovoitov wrote:
On 10/12/15 8:51 PM, Wangnan (F) wrote:
why 'set disable' is needed ?
the example given in cover letter shows the use case where you want
to receive samples only within sys_write() syscall.
The example
On 2015/10/13 12:16, Alexei Starovoitov wrote:
On 10/12/15 8:51 PM, Wangnan (F) wrote:
why 'set disable' is needed ?
the example given in cover letter shows the use case where you want
to receive samples only within sys_write() syscall.
The example makes sense, but sys_write() is running on
On 10/12/15 8:51 PM, Wangnan (F) wrote:
why 'set disable' is needed ?
the example given in cover letter shows the use case where you want
to receive samples only within sys_write() syscall.
The example makes sense, but sys_write() is running on this cpu, so just
disabling it on the current one
On 2015/10/13 11:39, Alexei Starovoitov wrote:
On 10/12/15 8:27 PM, Wangnan (F) wrote:
Then how to avoid racing? For example, when one core disabling all
events
in a map, another core is enabling all of them. This racing may causes
sereval
perf events in a map dump samples while other events
On 10/12/15 8:27 PM, Wangnan (F) wrote:
Then how to avoid racing? For example, when one core disabling all events
in a map, another core is enabling all of them. This racing may causes
sereval
perf events in a map dump samples while other events not. To avoid such
racing
I think some locking
On 2015/10/13 3:29, Alexei Starovoitov wrote:
On 10/12/15 2:02 AM, Kaixu Xia wrote:
+extern const struct bpf_func_proto bpf_perf_event_sample_enable_proto;
+extern const struct bpf_func_proto bpf_perf_event_sample_disable_proto;
externs are unnecessary. Just make them static.
Also I prefer
On 10/12/15 2:02 AM, Kaixu Xia wrote:
+extern const struct bpf_func_proto bpf_perf_event_sample_enable_proto;
+extern const struct bpf_func_proto bpf_perf_event_sample_disable_proto;
externs are unnecessary. Just make them static.
Also I prefer single helper that takes a flag, so we can extend
The functions bpf_perf_event_sample_enable/disable() can set the
flag sample_disable to enable/disable output trace data on samples.
Signed-off-by: Kaixu Xia
---
include/linux/bpf.h | 2 ++
include/uapi/linux/bpf.h | 2 ++
kernel/bpf/verifier.c| 4 +++-
kernel/trace/bpf_trace.c | 34
The functions bpf_perf_event_sample_enable/disable() can set the
flag sample_disable to enable/disable output trace data on samples.
Signed-off-by: Kaixu Xia
---
include/linux/bpf.h | 2 ++
include/uapi/linux/bpf.h | 2 ++
kernel/bpf/verifier.c| 4 +++-
On 10/12/15 2:02 AM, Kaixu Xia wrote:
+extern const struct bpf_func_proto bpf_perf_event_sample_enable_proto;
+extern const struct bpf_func_proto bpf_perf_event_sample_disable_proto;
externs are unnecessary. Just make them static.
Also I prefer single helper that takes a flag, so we can extend
On 2015/10/13 3:29, Alexei Starovoitov wrote:
On 10/12/15 2:02 AM, Kaixu Xia wrote:
+extern const struct bpf_func_proto bpf_perf_event_sample_enable_proto;
+extern const struct bpf_func_proto bpf_perf_event_sample_disable_proto;
externs are unnecessary. Just make them static.
Also I prefer
On 2015/10/13 12:16, Alexei Starovoitov wrote:
On 10/12/15 8:51 PM, Wangnan (F) wrote:
why 'set disable' is needed ?
the example given in cover letter shows the use case where you want
to receive samples only within sys_write() syscall.
The example makes sense, but sys_write() is running on
On 10/12/15 8:51 PM, Wangnan (F) wrote:
why 'set disable' is needed ?
the example given in cover letter shows the use case where you want
to receive samples only within sys_write() syscall.
The example makes sense, but sys_write() is running on this cpu, so just
disabling it on the current one
On 10/12/15 9:34 PM, Wangnan (F) wrote:
On 2015/10/13 12:16, Alexei Starovoitov wrote:
On 10/12/15 8:51 PM, Wangnan (F) wrote:
why 'set disable' is needed ?
the example given in cover letter shows the use case where you want
to receive samples only within sys_write() syscall.
The example
On 10/12/15 8:27 PM, Wangnan (F) wrote:
Then how to avoid racing? For example, when one core disabling all events
in a map, another core is enabling all of them. This racing may causes
sereval
perf events in a map dump samples while other events not. To avoid such
racing
I think some locking
On 2015/10/13 11:39, Alexei Starovoitov wrote:
On 10/12/15 8:27 PM, Wangnan (F) wrote:
Then how to avoid racing? For example, when one core disabling all
events
in a map, another core is enabling all of them. This racing may causes
sereval
perf events in a map dump samples while other events
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