* [Bug translator/22312] bpf: global variable locking
2017-10-18 21:45 [Bug translator/22312] New: bpf: global variable locking amerey at redhat dot com
@ 2017-10-20 22:22 ` amerey at redhat dot com
2018-07-12 19:57 ` me at serhei dot io
` (6 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: amerey at redhat dot com @ 2017-10-20 22:22 UTC (permalink / raw)
To: systemtap
https://sourceware.org/bugzilla/show_bug.cgi?id=22312
--- Comment #1 from Aaron Merey <amerey at redhat dot com> ---
We want to implement stap's locking of globals on a per-probe basis.
--
You are receiving this mail because:
You are the assignee for the bug.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug translator/22312] bpf: global variable locking
2017-10-18 21:45 [Bug translator/22312] New: bpf: global variable locking amerey at redhat dot com
2017-10-20 22:22 ` [Bug translator/22312] " amerey at redhat dot com
@ 2018-07-12 19:57 ` me at serhei dot io
2018-08-09 14:35 ` [Bug bpf/22312] " me at serhei dot io
` (5 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: me at serhei dot io @ 2018-07-12 19:57 UTC (permalink / raw)
To: systemtap
https://sourceware.org/bugzilla/show_bug.cgi?id=22312
Serhei Makarov <me at serhei dot io> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |me at serhei dot io
--- Comment #2 from Serhei Makarov <me at serhei dot io> ---
https://sourceware.org/ml/systemtap/2018-q3/msg00017.html describes one
possible way of doing this:
BPF_XADD(&lock_counter, 1);
value = read(lock_counter);
if (value <= 1) { ... execute probe ... } else skip probe
BPF_XADD(&lock_counter, -1);
--
You are receiving this mail because:
You are the assignee for the bug.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug bpf/22312] bpf: global variable locking
2017-10-18 21:45 [Bug translator/22312] New: bpf: global variable locking amerey at redhat dot com
2017-10-20 22:22 ` [Bug translator/22312] " amerey at redhat dot com
2018-07-12 19:57 ` me at serhei dot io
@ 2018-08-09 14:35 ` me at serhei dot io
2019-04-08 16:14 ` [Bug bpf/22312] bpf: global variable and statistics aggregate locking me at serhei dot io
` (4 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: me at serhei dot io @ 2018-08-09 14:35 UTC (permalink / raw)
To: systemtap
https://sourceware.org/bugzilla/show_bug.cgi?id=22312
Serhei Makarov <me at serhei dot io> changed:
What |Removed |Added
----------------------------------------------------------------------------
Component|translator |bpf
--
You are receiving this mail because:
You are the assignee for the bug.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug bpf/22312] bpf: global variable and statistics aggregate locking
2017-10-18 21:45 [Bug translator/22312] New: bpf: global variable locking amerey at redhat dot com
` (2 preceding siblings ...)
2018-08-09 14:35 ` [Bug bpf/22312] " me at serhei dot io
@ 2019-04-08 16:14 ` me at serhei dot io
2019-04-12 17:41 ` me at serhei dot io
` (3 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: me at serhei dot io @ 2019-04-08 16:14 UTC (permalink / raw)
To: systemtap
https://sourceware.org/bugzilla/show_bug.cgi?id=22312
Serhei Makarov <me at serhei dot io> changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|bpf: global variable |bpf: global variable and
|locking |statistics aggregate
| |locking
--- Comment #3 from Serhei Makarov <me at serhei dot io> ---
Becomes especially important if we want to get exact results from statistical
aggregates (PR23476). There is some BPF upstream work (discussed at LPC 2018)
that will eventually make this easier to implement properly.
--
You are receiving this mail because:
You are the assignee for the bug.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug bpf/22312] bpf: global variable and statistics aggregate locking
2017-10-18 21:45 [Bug translator/22312] New: bpf: global variable locking amerey at redhat dot com
` (3 preceding siblings ...)
2019-04-08 16:14 ` [Bug bpf/22312] bpf: global variable and statistics aggregate locking me at serhei dot io
@ 2019-04-12 17:41 ` me at serhei dot io
2019-05-06 17:04 ` me at serhei dot io
` (2 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: me at serhei dot io @ 2019-04-12 17:41 UTC (permalink / raw)
To: systemtap
https://sourceware.org/bugzilla/show_bug.cgi?id=22312
--- Comment #4 from Serhei Makarov <me at serhei dot io> ---
Newer kernels will include a spinlock primitive:
https://github.com/torvalds/linux/blob/master/include/uapi/linux/bpf.h#L2346
On older kernels we may either use the XADD method or just print a warning and
skip locking altogether.
--
You are receiving this mail because:
You are the assignee for the bug.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug bpf/22312] bpf: global variable and statistics aggregate locking
2017-10-18 21:45 [Bug translator/22312] New: bpf: global variable locking amerey at redhat dot com
` (4 preceding siblings ...)
2019-04-12 17:41 ` me at serhei dot io
@ 2019-05-06 17:04 ` me at serhei dot io
2019-06-26 19:40 ` me at serhei dot io
2019-06-26 20:29 ` me at serhei dot io
7 siblings, 0 replies; 9+ messages in thread
From: me at serhei dot io @ 2019-05-06 17:04 UTC (permalink / raw)
To: systemtap
https://sourceware.org/bugzilla/show_bug.cgi?id=22312
Serhei Makarov <me at serhei dot io> changed:
What |Removed |Added
----------------------------------------------------------------------------
Depends on| |24528
Referenced Bugs:
https://sourceware.org/bugzilla/show_bug.cgi?id=24528
[Bug 24528] bpf-next housekeeping: bpf-translate.cxx should distinguish codegen
for kernel/userspace targets
--
You are receiving this mail because:
You are the assignee for the bug.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug bpf/22312] bpf: global variable and statistics aggregate locking
2017-10-18 21:45 [Bug translator/22312] New: bpf: global variable locking amerey at redhat dot com
` (5 preceding siblings ...)
2019-05-06 17:04 ` me at serhei dot io
@ 2019-06-26 19:40 ` me at serhei dot io
2019-06-26 20:29 ` me at serhei dot io
7 siblings, 0 replies; 9+ messages in thread
From: me at serhei dot io @ 2019-06-26 19:40 UTC (permalink / raw)
To: systemtap
https://sourceware.org/bugzilla/show_bug.cgi?id=22312
--- Comment #5 from Serhei Makarov <me at serhei dot io> ---
If we go with the 'print a warning' method, should only print if the script is
using some feature that's particularly sensitive to locking. Currently the
@variance calculation looks to be a candidate for that.
--
You are receiving this mail because:
You are the assignee for the bug.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug bpf/22312] bpf: global variable and statistics aggregate locking
2017-10-18 21:45 [Bug translator/22312] New: bpf: global variable locking amerey at redhat dot com
` (6 preceding siblings ...)
2019-06-26 19:40 ` me at serhei dot io
@ 2019-06-26 20:29 ` me at serhei dot io
7 siblings, 0 replies; 9+ messages in thread
From: me at serhei dot io @ 2019-06-26 20:29 UTC (permalink / raw)
To: systemtap
https://sourceware.org/bugzilla/show_bug.cgi?id=22312
Bug 22312 depends on bug 24528, which changed state.
Bug 24528 Summary: stapbpf-next housekeeping: bpf-translate.cxx should distinguish codegen for kernel/userspace targets
https://sourceware.org/bugzilla/show_bug.cgi?id=24528
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution|--- |FIXED
--
You are receiving this mail because:
You are the assignee for the bug.
^ permalink raw reply [flat|nested] 9+ messages in thread