Only small number of functions are available for tracing in nv-dmabuf.c

[zhiyongww]

Hey, I'm debugging the performance of cuMemGetHandleForAddressRange, sometimes it takes longer time than expected when registering dma buff. Upon on further investigation, I found the problem within nv_dma_buf_export.

[[email protected] ~]# retsnoop -S -e nv_dma_buf_export -e nvidia_dev_get
Receiving data...
13:35:09.034148 -> 13:35:09.036017 TID/PID 552610/552610 (cumem/cumem):

               entry_SYSCALL_64_after_hwframe+0x46  (entry_SYSCALL_64 @ arch/x86/entry/entry_64.S:120)
               do_syscall_64+0x3d                   (arch/x86/entry/common.c:80)
               . do_syscall_x64                     (arch/x86/entry/common.c:50)
               __x64_sys_ioctl+0x88                 (fs/ioctl.c:856)
               . __se_sys_ioctl                     (fs/ioctl.c:856)
               . __do_sys_ioctl                     (fs/ioctl.c:870)
               . vfs_ioctl                          (fs/ioctl.c:52)
               nvidia_frontend_unlocked_ioctl+0x3c
               nvidia_ioctl+0x588
   1868us [0]  nv_dma_buf_export+0x254
!   591us [0]  nvidia_dev_get


13:35:14.218524 -> 13:35:14.218586 TID/PID 555543/555543 (cumem/cumem):

              entry_SYSCALL_64_after_hwframe+0x46  (entry_SYSCALL_64 @ arch/x86/entry/entry_64.S:120)
              do_syscall_64+0x3d                   (arch/x86/entry/common.c:80)
              . do_syscall_x64                     (arch/x86/entry/common.c:50)
              __x64_sys_ioctl+0x88                 (fs/ioctl.c:856)
              . __se_sys_ioctl                     (fs/ioctl.c:856)
              . __do_sys_ioctl                     (fs/ioctl.c:870)
              . vfs_ioctl                          (fs/ioctl.c:52)
              nvidia_frontend_unlocked_ioctl+0x3c
              nvidia_ioctl+0x588
    62us [0]  nv_dma_buf_export+0x254
!   21us [0]  nvidia_dev_get

But inside the kernel-open/nvidia/nv-dmabuf.c, only a few functions are available for tracing, I was wondering how to enable the traces for all functions inside this file? like all the function called in nv_dma_buf_create. and even to trace the potential lock contention problem.

[[email protected] ~]# cat /sys/kernel/tracing/available_filter_functions  | grep nv_dma_buf
nv_dma_buf_export [nvidia]
nv_dma_buf_dup_mem_handles [nvidia]
nv_dma_buf_get_phys_addresses [nvidia]
nv_dma_buf_put_phys_addresses [nvidia]
nv_dma_buf_undup_mem_handles [nvidia]
nv_dma_buf_map [nvidia]
nv_dma_buf_unmap [nvidia]
nv_dma_buf_release [nvidia]
nv_dma_buf_mmap [nvidia]

Thanks!

cc: @mtijanic could you please take a look? could we do similar thing in #675?