Messages in this thread | | | Subject | Re: [rfc] Describe events in a structured way via sysfs | From | Lin Ming <> | Date | Mon, 21 Jun 2010 16:55:09 +0800 |
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> From: Ingo Molnar <mingo@elte.hu> > > * Peter Zijlstra <peterz@infradead.org> wrote: > > > On Thu, 2010-05-20 at 16:12 -0700, Greg KH wrote: > > > > How deep in the device tree are you really going to be > > > caring about? It sounds like the large majority of > > > events are only going to be coming from the "system" > > > type objects (cpu, nodes, memory, etc.) and very few > > > would be from things that we consider a 'struct > > > device' today (like a pci, usb, scsi, or input, etc.) > > > > The general noise I hear from the hardware people is > > that we'll see more and more device-level stuff - bus > > bridges/controller and actual devices (GPUs, NICs etc.) > > will be wanting to export performance metrics. > > There's (much) more: > > - laptops want to provide power level/usage metrics, > > - we could express a lot of special, lower level > (transport specific) disk IO stats via events as well - > without having to push those stats to a higher level > (where it might not make sense). Currently such kinds > of stats/metrics are very device/subsystem specific > way, if they are provided at all. > > Also, we already have quite a few per device tracepoints > upstream. Here are a few examples: > > - GPU tracepoints (trace_i915_gem_request_submit(), etc.) > - WIFI tracepoints (trace_iwlwifi_dev_ioread32(), etc.) > - block tracepoints (trace_block_bio_complete()) > > So these would be attached to: > > # GEM events of drm/card0: > /sys/devices/pci0000:00/0000:00:02.0/drm/card0/events/i915_gem_request_submit/ > > # Wifi-ioread events of wlan0: > /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/net/wlan0/events/iwlwifi_dev_ioread32/ > > # whole sdb disk events: > /sys/block/sdb/events/block_bio_complete/ > > # sdb1 partition events: > /sys/block/sdb/sdb1/events/block_bio_complete/ > > And we also have 'software nodes' in /sys that have events > upstream here and today. For example for SLAB we already > have kmalloc/kfree tracepoints (trace_kmalloc() and > trace_kfree()): > > # all kmalloc events: > /sys/kernel/slab/events/ > > # kmalloc events for sighand_cache: > /sys/kernel/slab/sighand_cache/events/kmalloc/ > > # kfree events for sighand_cache: > /sys/kernel/slab/sighand_cache/events/kfree/ > > In general the set of events we have upstream is growing > along an exponential curve (there's over a hundred now, > via tracepoints). > > They are either logically attached to the hardware > topology of the system (as in the first set of examples > above), or ae attached to the software/subsystem object > topology of the kernel (some examples of which are > described in the second set of examples above). > > Sometimes there are aliasing/filtering relationship > between events, which is expressed very well via the > hierarchy and granularity of /sysfs. > > New events would go into that topology there in a natural > way. > > For example general hugepage tracepoints (should we > introduce any) would go into the existing hugepage node: > > /sys/kernel/mm/hugepages/events/... > > All in one, all these existing and future events, both of > hardware and software type, are literally begging to be > attached to nodes in /sys :-)
(sorry for late response...)
There are so many events via tracepoints, how about below sysfs point for each events?
1. kvm events /sys/devices/system/kvm/kvm0/events/kvm_set_irq/ ... /sys/devices/system/kvm/kvm0/events/kvm_emulate_insn/
2. kvm_mmu events /sys/devices/system/kvm/kvm0/events/kvm_mmu_pagetable_walk/ ... /sys/devices/system/kvm/kvm0/events/kvm_mmu_zap_page/
3. raw_syscalls events /sys/kernel/events/sys_enter/ /sys/kernel/events/sys_exit/
4. mce events /sys/devices/system/machinecheck/machinecheck0/mce_record/ ... /sys/devices/system/machinecheck/machinecheckN/mce_record/
5. sched events /sys/kernel/events/sched_kthread_stop/ ... /sys/kernel/events/sched_stat_runtime/
6. irq events /sys/kernel/events/irq_handler_entry/ ... /sys/kernel/events/softirq_exit/
7. timer events /sys/kernel/events/timer_init/ ... /sys/kernel/events/itimer_expire/
8. signal events /sys/kernel/events/signal_generate/ ... /sys/kernel/events/signal_lose_info/
9. workqueue events /sys/kernel/events/workqueue_insertion/ ... /sys/kernel/events/workqueue_destruction/
10. lock events /sys/kernel/events/lock_acquire/ ... /sys/kernel/events/lock_acquired/
11. module events /sys/module/events/module_load/ ... /sys/module/events/module_request/
12. power events /sys/power/events/power_start/ ... /sys/power/events/power_end/
13. kmem events /sys/kernel/mm/events/kmalloc/ ... /sys/kernel/mm/events/mm_page_alloc_extfrag/
14. ext4 events /sys/fs/events/ext4_free_inode/ ... /sys/fs/events/ext4_mb_buddy_bitmap_load/
15. jbd2 events /sys/fs/events/jbd2_checkpoint/ ... /sys/fs/events/jbd2_cleanup_journal_tail/
16. xfs events /sys/fs/events/xfs_attr_list_sf/ ... /sys/fs/events/xfs_log_recover_inode_skip/
17. gfs2 events /sys/fs/events/gfs2_glock_state_change/ ... /sys/fs/events/gfs2_block_alloc/
18. block events /sys/block/sda/events/block_rq_abort/ ... /sys/block/sdb/events/block_rq_remap/
19. bkl events /sys/kernel/events/lock_kernel/ ... /sys/kernel/events/unlock_kernel/
20. scsi events /sys/bus/scsi/devices/0:0:0:0/events/scsi_dispatch_cmd_start/ ... /sys/bus/scsi/devices/0:0:0:0/events/scsi_eh_wakeup/
21. iwlwifi_io events /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/net/wlan0/events/iwlwifi_dev_ioread32/ ... /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/net/wlan0/events/iwlwifi_dev_ucode_event/
22. iwm events <where should iwm events be in sysfs?>
23. skb events /sys/class/net/events/kfree_skb/ /sys/class/net/events/skb_copy_datagram_iovec/
24. napi events /sys/class/net/events/napi/
25. mac80211 events /sys/class/net/events/drv_start/ ... /sys/class/net/events/stop_queue
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