On Tue, Mar 08, 2016 at 02:49:01PM +0100, Ingo Molnar wrote: > > * Peter Zijlstra <pet...@infradead.org> wrote: > > > On Mon, Mar 07, 2016 at 03:50:14AM +0000, Wang Nan wrote: > > > This patch set has been posted multiple times (with and without > > > corresponding 'perf tool' patches), and doesn't receive further > > > comment. I think it should be okay to merge them into mainline. > > > There are many perf's improvement depend on it. However, Peter > > > is not responsive after I fixed some problems he pointed out. > > > > > > Introduces 'write_backward' into perf_event_attr, allows kernel > > > writing the ring buffer from the end of it. This feature allows > > > extracting data from overwritable ring buffer. > > > > > > Wang Nan (5): > > > perf core: Introduce new ioctl options to pause and resume ring buffer > > > perf core: Set event's default overflow_handler > > > perf core: Prepare writing into ring buffer from end > > > perf core: Add backward attribute to perf event > > > perf core: Reduce perf event output overhead by new overflow handler > > > > perf kernel features are currently on hold until I can manage to run a > > fuzzer for more than a few minutes without my machine having a seizure. > > Btw., could you describe exactly what commands you are running, with what > configuration options (if that matters), so that people who'd like our > feature > freeze to be lifted can help out?
Mostly syz-kaller, but also Vince's perf-fuzzer and your perf-stress script, which I'm not sure is publicly available. perf_fuzzer lives at: https://github.com/deater/perf_event_tests.git Here's a thread on syz-kaller: lkml.kernel.org/r/CACT4Y+Ym0TZLkmRrM0ZGgLpu8kqS-YjoWTMrvaLz=tx2tny...@mail.gmail.com If things have shifted again I'm sure Dmitry is willing to help. I run the thing natively on actual real hardware, which ensure I get to test the PMU drivers too. # cat go-fuzz.sh #!/bin/bash echo 1 > /proc/sys/kernel/traceoff_on_warning echo 1 > /debug/tracing/options/stacktrace echo 1 > /debug/tracing/events/sched/enable cd gopath/src/github.com/google/syzkaller/ ./bin/syz-manager -config perf.cfg # cat gopath/src/github.com/google/syzkaller/perf.cfg { "http": "localhost:50000", "workdir": "/root/gopath/src/github.com/google/syzkaller/workdir", "syzkaller": "/root/gopath/src/github.com/google/syzkaller", "vmlinux": "-", "type": "local", "count": 1, "procs": 160, "cover": false, "dropprivs": false, "enable_syscalls": [ "getpid", "gettid", "perf_event_open", "ioctl$PERF*", "prctl$void", "bpf$*", "sched_yield" ] }
