Re: [Qemu-devel] What's the intended use of log.h logging?

[Paolo Bonzini]

On 16/10/2015 15:36, Peter Maydell wrote:
>> We could add "-d trace:help" to list valid tracepoint names.
> 
> I think people are mostly going to care about categories
> (eg "enable tracing for device X", or "enable tracing for
> all unimplemented features", or "enable a medium level of
> debug tracing for device Y".

I hadn't thought about levels, but honestly when I use KVM tracing (which
is often measured in tens of megabytes per run) I don't care.  I just
get a .xz file from the person who reported the bug, with all the events,
and use less/grep on it.

> If we want to get there we need to define standards for
> naming tracepoints and enforce them somehow
> (subsystem_category_level_tracepointname ?)

We're surprisingly good at naming tracepoints.  Only 13 files
do not have a common prefix for their tracepoints, conflicts are rare,
and only a few files could arguably improve their naming:

hw/usb/desc.c                    usb_desc, usb_set, usb_clear                   
          !!
hw/vfio/platform.c               vfio_platform (except for one)                 
          !!
migration/savevm.c               savevm, qemu_loadvm, vmstate, 
qemu_announce_self_iter    !!
target-s390x/mmu_helper.c        (none)                                         
          !!
target-sparc/int32_helper.c      int_helper                                     
          !!
target-sparc/int64_helper.c      int_helper                                     
          !!
target-sparc/mmu_helper.c        mmu_helper                                     
          !!
target-sparc/win_helper.c        win_helper                                     
          !!
xen-hvm.c                        handle_ioreq, cpu_ioreq, xen                   
          !!

Globbing should suffice, IMHO.

Full list of prefixes under my signature.

Paolo

audio/alsaaudio.c                alsa
audio/ossaudio.c                 oss
balloon.c                        virtio_balloon
block/backup.c                   backup
block.c                          bdrv
block/commit.c                   commit
blockdev.c                       qmp_block
block/mirror.c                   mirror
block/qcow2-cache.c              qcow2
block/qcow2-cluster.c            qcow2
block/qcow2.c                    qcow2
block/qed.c                      qed
block/qed-l2-cache.c             qed
block/qed-table.c                qed
block/raw-posix.c                paio_submit
block/stream.c                   stream
cpu-exec.c                       exec_tb
crypto/tlscredsanon.c            qcrypto_tls_creds_anon
crypto/tlscreds.c                qcrypto_tls_creds
crypto/tlscredsx509.c            qcrypto_tls_creds_x509
crypto/tlssession.c              qcrypto_tls_session
dma-helpers.c                    dma
hw/9pfs/virtio-9p.c              v9fs
hw/acpi/memory_hotplug.c         mhp_acpi
hw/arm/virt-acpi-build.c         virt_acpi
hw/audio/cs4231.c                cs4231
hw/audio/milkymist-ac97.c        milkymist_ac97
hw/block/dataplane/virtio-blk.c  virtio_blk_data_plane
hw/block/hd-geometry.c           hd_geometry
hw/block/virtio-blk.c            virtio_blk
hw/char/escc.c                   escc
hw/char/grlib_apbuart.c          grlib_apbuart
hw/char/lm32_juart.c             lm32_juart
hw/char/lm32_uart.c              lm32_uart
hw/char/milkymist-uart.c         milkymist_uart
hw/char/virtio-console.c         virtio_console
hw/char/virtio-serial-bus.c      virtio_serial
hw/display/g364fb.c              g364fb
hw/display/jazz_led.c            jazz_led
hw/display/milkymist-tmu2.c      milkymist_tmu2
hw/display/milkymist-vgafb.c     milkymist_vgafb_memory
hw/display/qxl.c                 qxl
hw/display/qxl-render.c          qxl_render
hw/display/virtio-gpu.c          virtio_gpu
hw/display/vmware_vga.c          vmware
hw/display/xenfb.c               xenfb
hw/dma/i8257.c                   i8257
hw/dma/rc4030.c                  rc4030, jazzio
hw/dma/sparc32_dma.c             sparc32, espdma, ledma
hw/dma/sun4m_iommu.c             sun4m_iommu
hw/i386/pc.c                     mhp_pc_dimm
hw/i386/xen/xen_platform.c       xen
hw/i386/xen/xen_pvdevice.c       xen_pv_mmio
hw/input/milkymist-softusb.c     milkymist_softusb
hw/input/ps2.c                   ps2
hw/intc/apic.c                   apic
hw/intc/apic_common.c            cpu, apic
hw/intc/grlib_irqmp.c            grlib_irqmp
hw/intc/lm32_pic.c               lm32_pic
hw/intc/s390_flic_kvm.c          flic
hw/intc/slavio_intctl.c          slavio
hw/intc/xics.c                   xics
hw/isa/pc87312.c                 pc87312
hw/misc/eccmemctl.c              ecc
hw/misc/milkymist-hpdmc.c        milkymist_hpdmc_memory
hw/misc/milkymist-pfpu.c         milkymist_pfpu
hw/misc/slavio_misc.c            slavio
hw/net/lance.c                   lance
hw/net/milkymist-minimac2.c      milkymist_minimac2
hw/net/mipsnet.c                 mipsnet
hw/net/opencores_eth.c           open_eth
hw/net/pcnet.c                   pcnet
hw/net/pcnet-pci.c               pcnet
hw/nvram/ds1225y.c               nvram
hw/nvram/fw_cfg.c                fw_cfg
hw/pci/pci.c                     pci_update_mappings
hw/pci/pci_host.c                pci_cfg
hw/ppc/ppc.c                     ppc
hw/ppc/spapr.c                   spapr_cas
hw/ppc/spapr_hcall.c             spapr_cas
hw/ppc/spapr_iommu.c             spapr_iommu
hw/ppc/spapr_pci.c               spapr_pci
hw/s390x/css.c                   css
hw/s390x/virtio-ccw.c            virtio_ccw
hw/scsi/esp.c                    esp
hw/scsi/esp-pci.c                esp_pci
hw/scsi/megasas.c                megasas
hw/scsi/scsi-bus.c               scsi_req, scsi
hw/scsi/vmw_pvscsi.c             pvscsi
hw/sd/milkymist-memcard.c        milkymist_memcard_memory
hw/sparc/leon3.c                 leon3
hw/sparc/sun4m.c                 sun4m_cpu
hw/timer/grlib_gptimer.c         grlib_gptimer
hw/timer/lm32_timer.c            lm32_timer
hw/timer/milkymist-sysctl.c      milkymist_sysctl
hw/timer/slavio_timer.c          slavio
hw/usb/bus.c                     usb_port
hw/usb/core.c                    usb_packet_state
hw/usb/dev-hub.c                 usb_hub
hw/usb/dev-mtp.c                 usb_mtp
hw/usb/dev-uas.c                 usb_uas
hw/usb/hcd-ehci.c                usb_ehci
hw/usb/hcd-ohci.c                usb_ohci
hw/usb/hcd-uhci.c                usb_uhci
hw/usb/hcd-xhci.c                usb_xhci
hw/usb/host-libusb.c             usb_host
hw/vfio/pci.c                    vfio
hw/vfio/pci-quirks.              vfio_quirk
hw/vfio/vfio-common.c            vfio
hw/virtio/dataplane/vring.c      vring
hw/virtio/virtio.c               virtio, virtqueue
hw/virtio/virtio-rng.c           virtio_rng
ioport.c                         cpu
kvm-all.c                        kvm
memory.c                         memory_region_ops
migration.c                      migration, migrate
migration/ram.c                  migration
migration/rdma.c                 qemu_rdma, rdma
monitor.c                        monitor_protocol
qemu-coroutine.c                 qemu_coroutine
qemu-coroutine-lock.c            qemu_co
qemu-file.c                      qemu_file
qom/object.c                     object
spice-qemu-char.c                spice_vmc
target-ppc/kvm.c                 kvm
target-s390x/cpu.c               cpu
target-s390x/ioinst.c            ioinst
target-s390x/kvm.c               kvm
thread-pool.c                    thread_pool
translate-all.c                  translate
ui/console.c                     displaychangelistener, displaysurface, console
ui/gtk.c                         gd
ui/input.c                       input
ui/spice-display.c               qemu_spice
ui/vnc.c                         vnc_key
util/hbitmap.c                   hbitmap
vl.c                             qemu_system
vmstate.c                        vmstate
xen-mapcache.c                   xen