DTrace Hangout 30 March 2017
- gnn@ has committed the fork() fixes so we now get two returns as we should
- samuel's race condition is found and fixed and only relates to xnu code
- rwatson@ has committed his audit provder, samuel will find the xnu audit person and point them at that work.
- samuel has been adding all the FreeBSD dtrace man pages to xnu which will be useful in future but requires a new source drop
- samuel has modified the Apple libdtrace to grab arguments for fbt using the same trick as is used for pid providers
- samuel continues to bring xnu closer to FreeBSD
- domagoj has patches for kqueue to notify user space for probes being installed on which VM. This work is on a kqueue branch in domagoj's github repo.
- gnn is working on adding a dt_probe() system call for use from user space. bkidney@ explains why we need this for CADETS/LOOM. samuel asks about using libusdt, but bkidney@ points out that this won't work because of the need to define probes at run time.
- arun@ has ported the buflimit patches to FreeBSD but for the workload he tested it didn't seem to help. Just making the buffers large helped more than the patches. samuel asks if the scheduler is pushing our priority down. samuel says they had this problem on xnu and so they have dtrace run at a fixed priority.
- domagoj@ is working on the virtio driver so that DIF can be sent into the VM but that's in very early stages.
gnn@ will propose a DTrace section in the DevSummit in June