Android dmabuf_dump 工具的使用详解

本文是极客笔记出品，介绍如何使用dmabuf_dump工具。

什么是DMA-BUF

dma-buf 的出现就是为了解决各个驱动之间 buffer 共享的问题，因此它本质上是 buffer 与 file 的结合，即 dma-buf 既是块物理 buffer，又是个 linux file。

buffer 是内容，file 是媒介，只有通过 file 这个媒介才能实现同一 buffer 在不同驱动之间的流转。

• exporter： 分配 buffer 的模块
• importer/user：使用 buffer 的模块

dmabuf_dump工具介绍

dmabuf_dump是一个可执行文件，接收参数调用libdmabufinfo.a的接口完成dump功能，代码在：system/memory/libmeminfo/libdmabufinfo/tools/

结构如下（基于Android 13）：

包含如下功能：

1. Dump整个系统DMA-BUF per-buffer, per-exporter and per-device statistics(dmabuf_dump -b)，在kernel版本>= 5.10上生效。
2. Dump整个系统的dmabuf info (dmabuf_dump)
3. Dump某个PID的dmabuf info (dmabuf_dump )
4. 以Table[buffer x process]方式呈现dmabuf info (dmabuf_dump -a)

dmabuf_dump工具的使用

Dump整个系统的dmabuf info

xxx:/ # dmabuf_dump
    mediaswcodec:774
                  Name              Rss              Pss         nr_procs            Inode
             <unknown>            32 kB             0 kB                2            54037
             <unknown>            32 kB             0 kB                2            63993
             <unknown>            16 kB             0 kB                2            63994
             <unknown>            16 kB             0 kB                2            63995
             <unknown>            32 kB             0 kB                2            64923
             <unknown>            32 kB             0 kB                2            64924
             <unknown>            32 kB             0 kB                2            64925
             <unknown>            32 kB             0 kB                2            64932
             <unknown>            16 kB             0 kB                2            64933
             <unknown>            32 kB             0 kB                2            65906
             <unknown>            32 kB             0 kB                2            66870
         PROCESS TOTAL           304 kB             0 kB
----------------------
 ndroid.systemui:1505
                  Name              Rss              Pss         nr_procs            Inode
             <unknown>           392 kB           196 kB                2            45482
             <unknown>           392 kB           130 kB                3            45484
             <unknown>           196 kB            65 kB                3            45489
             <unknown>           392 kB           130 kB                3            46741
             <unknown>          4160 kB          1386 kB                3            49696
             <unknown>           196 kB            65 kB                3            51564
             <unknown>           196 kB            65 kB                3            51566
             <unknown>            16 kB            16 kB                1            51802
             <unknown>            16 kB            16 kB                1            53584
             <unknown>            16 kB            16 kB                1            64935
             <unknown>            16 kB            16 kB                1            65914
             <unknown>            16 kB            16 kB                1            65916
             <unknown>            16 kB            16 kB                1            65918
             <unknown>            16 kB            16 kB                1            66879
             <unknown>            16 kB            16 kB                1            66882
         PROCESS TOTAL          6052 kB          2167 kB
----------------------
 droid.launcher3:1903
                  Name              Rss              Pss         nr_procs            Inode
             <unknown>            68 kB            68 kB                1            44867
             <unknown>            68 kB            68 kB                1            44870
             <unknown>            68 kB            68 kB                1            44872
             <unknown>            52 kB            52 kB                1            50076
             <unknown>            52 kB            52 kB                1            50078
             <unknown>            52 kB            52 kB                1            51809
             <unknown>            52 kB            52 kB                1            51811
             <unknown>            52 kB            52 kB                1            52583
             <unknown>            52 kB            52 kB                1            53586
             <unknown>            52 kB            52 kB                1            53598
             <unknown>            52 kB            52 kB                1            62391
             <unknown>            52 kB            52 kB                1            62396
             <unknown>            52 kB            52 kB                1            62398
             <unknown>            52 kB            52 kB                1            62400
             <unknown>            52 kB            52 kB                1            62402
             <unknown>            52 kB            52 kB                1            62523
             <unknown>            52 kB            52 kB                1            62525
             <unknown>            52 kB            52 kB                1            62527
             <unknown>            52 kB            52 kB                1            62529
             <unknown>            52 kB            52 kB                1            62531
             <unknown>            52 kB            52 kB                1            62533
             <unknown>          5072 kB          1690 kB                3            66874
             <unknown>          5072 kB          1690 kB                3            66876
             <unknown>          5072 kB          1690 kB                3            66877
         PROCESS TOTAL         16356 kB          6211 kB
----------------------
     mediaserver:681
                  Name              Rss              Pss         nr_procs            Inode
             <unknown>            32 kB             0 kB                2            54037
             <unknown>            32 kB            32 kB                2            63993
             <unknown>            16 kB             0 kB                2            63994
             <unknown>            16 kB             0 kB                2            63995
             <unknown>            32 kB             0 kB                2            64923
             <unknown>            32 kB            32 kB                2            64924
             <unknown>            32 kB            32 kB                2            64925
             <unknown>            32 kB             0 kB                2            64932
             <unknown>            16 kB             0 kB                2            64933
             <unknown>            32 kB             0 kB                2            65906
             <unknown>            32 kB            32 kB                2            66870
         PROCESS TOTAL           304 kB           128 kB
----------------------
  surfaceflinger:472
                  Name              Rss              Pss         nr_procs            Inode
             <unknown>          5072 kB          2536 kB                2            30958
             <unknown>          5072 kB          2536 kB                2            30960
             <unknown>          5072 kB          2536 kB                2            30962
             <unknown>           392 kB           196 kB                2            45482
             <unknown>           392 kB           130 kB                3            45484
             <unknown>           196 kB            65 kB                3            45489
             <unknown>           392 kB           130 kB                3            46741
             <unknown>          4160 kB          1386 kB                3            49696
             <unknown>           196 kB            65 kB                3            51564
             <unknown>           196 kB            65 kB                3            51566
             <unknown>          5072 kB          1690 kB                3            66874
             <unknown>          5072 kB          1690 kB                3            66876
             <unknown>          5072 kB          1690 kB                3            66877
         PROCESS TOTAL         36356 kB         14719 kB
----------------------
 composer@2.1-se:414
                  Name              Rss              Pss         nr_procs            Inode
             <unknown>          5072 kB          2536 kB                2            30958
             <unknown>          5072 kB          2536 kB                2            30960
             <unknown>          5072 kB          2536 kB                2            30962
             <unknown>           392 kB           130 kB                3            45484
             <unknown>           196 kB            65 kB                3            45489
             <unknown>           392 kB           130 kB                3            46741
             <unknown>          4160 kB          1386 kB                3            49696
             <unknown>           196 kB            65 kB                3            51564
             <unknown>           196 kB            65 kB                3            51566
             <unknown>          5072 kB          1690 kB                3            66874
             <unknown>          5072 kB          1690 kB                3            66876
             <unknown>          5072 kB          1690 kB                3            66877
         PROCESS TOTAL         35964 kB         14523 kB
----------------------
 keymaster@4.0-s:294
                  Name              Rss              Pss         nr_procs            Inode
             <unknown>            72 kB            72 kB                1            27411
             <unknown>            72 kB            72 kB                1            27412
         PROCESS TOTAL           144 kB           144 kB
----------------------
dmabuf total: 38072 kB kernel_rss: 0 kB userspace_rss: 95480 kB userspace_pss: 37895 kB

Dump某个PID的dmabuf info

Dump Camera Provider进程的dmabuf使用情况。

xxx:/ # dmabuf_dump 407
 provider@2.4-se:407
                  Name              Rss              Pss         nr_procs            Inode
             <unknown>            76 kB            76 kB                1            67578
             <unknown>             4 kB             4 kB                1            67580
             <unknown>             4 kB             4 kB                1            67581
             <unknown>             4 kB             4 kB                1            67582
             <unknown>             4 kB             4 kB                1            67583
             <unknown>             4 kB             4 kB                1            67584
             <unknown>           100 kB           100 kB                1            83420
             <unknown>            64 kB            64 kB                1            83421
             <unknown>         19396 kB         19396 kB                1            83453
             <unknown>          1016 kB             0 kB                1            83454
             <unknown>            24 kB            24 kB                1            83455
             <unknown>            36 kB            36 kB                1            83456
             <unknown>            12 kB            12 kB                1            83457
             <unknown>             8 kB             8 kB                1            83458
             <unknown>             4 kB             4 kB                1            83459
             <unknown>           384 kB           384 kB                1            83460
             <unknown>          1080 kB          1080 kB                1            83461
             <unknown>             4 kB             4 kB                1            83462
             <unknown>          1080 kB          1080 kB                1            83894
             <unknown>           976 kB           976 kB                1            84456
             <unknown>             8 kB             8 kB                1            84457
             <unknown>             4 kB             4 kB                1            84458
             <unknown>             4 kB             4 kB                1            84459
             <unknown>            76 kB            76 kB                1            84460
             <unknown>             4 kB             4 kB                1            84461
             <unknown>            12 kB            12 kB                1            84462
             <unknown>           176 kB           176 kB                1            86253
             <unknown>           264 kB           264 kB                1            86254
             <unknown>           312 kB           312 kB                1            86255
             <unknown>           196 kB           196 kB                1            86259
             <unknown>             4 kB             4 kB                1            86260
             <unknown>          1080 kB          1080 kB                1            86267
             <unknown>          1080 kB          1080 kB                1            86299
             <unknown>         19396 kB         19396 kB                1            86301
             <unknown>          1080 kB          1080 kB                1            86305
             <unknown>         19396 kB         19396 kB                1            86306
             <unknown>            96 kB            96 kB                1            88216
             <unknown>             4 kB             4 kB                1            88217
             <unknown>           116 kB           116 kB                1            88218
             <unknown>             4 kB             4 kB                1            88219
             <unknown>             4 kB             4 kB                1            88220
             <unknown>          4668 kB          4668 kB                1            88227
             <unknown>             4 kB             4 kB                1            88228
             <unknown>            64 kB            64 kB                1            88243
             <unknown>            24 kB            24 kB                1            88244
             <unknown>          1080 kB          1080 kB                1            88258
             <unknown>             4 kB             4 kB                1            89493
             <unknown>            24 kB            24 kB                1            89528
             <unknown>          2772 kB          2772 kB                1            89529
             <unknown>          1444 kB             0 kB                1            89544
             <unknown>           408 kB           408 kB                1            89545
             <unknown>            12 kB            12 kB                1            89547
             <unknown>             4 kB             4 kB                1            89548
             <unknown>          1444 kB             0 kB                1            89549
             <unknown>           408 kB           408 kB                1            89550
             <unknown>             4 kB             4 kB                1            89553
             <unknown>             4 kB             4 kB                1            89554
             <unknown>             4 kB             4 kB                1            89555
             <unknown>             4 kB             4 kB                1            89556
             <unknown>          1080 kB          1080 kB                1            89560
             <unknown>          1016 kB             0 kB                1            89568
             <unknown>            24 kB            24 kB                1            89569
             <unknown>            36 kB            36 kB                1            89570
             <unknown>            12 kB            12 kB                1            89571
             <unknown>             8 kB             8 kB                1            89572
             <unknown>             4 kB             4 kB                1            89573
             <unknown>           384 kB           384 kB                1            89574
             <unknown>             8 kB             8 kB                1            89579
             <unknown>          1080 kB          1080 kB                1            89589
             <unknown>         19396 kB         19396 kB                1            89594
             <unknown>             4 kB             4 kB                1            90233
             <unknown>          2772 kB          2772 kB                1            90235
             <unknown>             4 kB             4 kB                1            90236
             <unknown>             4 kB             4 kB                1            90237
             <unknown>             4 kB             4 kB                1            90238
             <unknown>           196 kB           196 kB                1            90239
             <unknown>           196 kB           196 kB                1            90240
             <unknown>          1080 kB          1080 kB                1            90250
             <unknown>         19396 kB         19396 kB                1            90257
             <unknown>          1016 kB             0 kB                1            90258
             <unknown>            24 kB            24 kB                1            90259
             <unknown>            36 kB            36 kB                1            90260
             <unknown>            12 kB            12 kB                1            90261
             <unknown>             8 kB             8 kB                1            90262
             <unknown>             4 kB             4 kB                1            90263
             <unknown>           384 kB           384 kB                1            90264
             <unknown>          1016 kB             0 kB                1            90269
             <unknown>            24 kB            24 kB                1            90270
             <unknown>            36 kB            36 kB                1            90271
             <unknown>            12 kB            12 kB                1            90272
             <unknown>             8 kB             8 kB                1            90273
             <unknown>           196 kB           196 kB                1            91304
             <unknown>            12 kB            12 kB                1            91305
             <unknown>          1080 kB          1080 kB                1            91314
             <unknown>         19396 kB         19396 kB                1            91326
             <unknown>             4 kB             4 kB                1            92161
             <unknown>             4 kB             4 kB                1            92162
             <unknown>          1080 kB          1080 kB                1            92171
             <unknown>           452 kB           452 kB                1            92174
             <unknown>           144 kB           144 kB                1            92175
             <unknown>            24 kB            24 kB                1            92176
             <unknown>          1080 kB          1080 kB                1            92177
         PROCESS TOTAL        152728 kB        145776 kB
----------------------
dmabuf total: 152728 kB kernel_rss: 0 kB userspace_rss: 152728 kB userspace_pss: 145776 kB

以Table[buffer x process]方式呈现dmabuf info

• 注意，该方式只能看整个系统的

xxx:/ # dmabuf_dump -a
    Dmabuf Inode |            Size |   Fd Ref Counts |  Map Ref Counts | keymaster@4.0-s:294   | composer@2.1-se:414   |  surfaceflinger:472   |     mediaserver:681   |    mediaswcodec:774   |   system_server:926   | ndroid.systemui:1505  | droid.launcher3:1903  |
           27412 |           72 kB |               0 |               1 |        0(     1) refs |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |
           27411 |           72 kB |               0 |               1 |        0(     1) refs |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |
           30960 |         5072 kB |               2 |               2 |                    -- |        1(     1) refs |        1(     1) refs |                    -- |                    -- |                    -- |                    -- |                    -- |
           30962 |         5072 kB |               2 |               2 |                    -- |        1(     1) refs |        1(     1) refs |                    -- |                    -- |                    -- |                    -- |                    -- |
           30958 |         5072 kB |               2 |               2 |                    -- |        1(     1) refs |        1(     1) refs |                    -- |                    -- |                    -- |                    -- |                    -- |
           45482 |          392 kB |               3 |               3 |                    -- |        1(     1) refs |        1(     1) refs |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           73784 |         5072 kB |               3 |               3 |                    -- |        1(     1) refs |        1(     1) refs |                    -- |                    -- |        1(     1) refs |                    -- |                    -- |
           66904 |         5072 kB |               1 |               1 |                    -- |        1(     1) refs |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |
           51564 |          196 kB |               3 |               3 |                    -- |        1(     1) refs |        1(     1) refs |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           73786 |         5072 kB |               1 |               1 |                    -- |        1(     1) refs |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |
           45489 |          196 kB |               3 |               3 |                    -- |        1(     1) refs |        1(     1) refs |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           46741 |          392 kB |               3 |               3 |                    -- |        1(     1) refs |        1(     1) refs |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           45484 |          392 kB |               3 |               3 |                    -- |        1(     1) refs |        1(     1) refs |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           51566 |          196 kB |               3 |               3 |                    -- |        1(     1) refs |        1(     1) refs |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           66909 |         5072 kB |               2 |               2 |                    -- |                    -- |        1(     1) refs |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           66907 |         5072 kB |               2 |               2 |                    -- |                    -- |        1(     1) refs |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           49696 |         4160 kB |               2 |               2 |                    -- |                    -- |        1(     1) refs |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           63993 |           32 kB |               2 |               1 |                    -- |                    -- |                    -- |        3(     1) refs |        1(     0) refs |                    -- |                    -- |                    -- |
           54037 |           32 kB |               2 |               0 |                    -- |                    -- |                    -- |        1(     0) refs |        1(     0) refs |                    -- |                    -- |                    -- |
           64924 |           32 kB |               2 |               1 |                    -- |                    -- |                    -- |        3(     1) refs |        1(     0) refs |                    -- |                    -- |                    -- |
           64923 |           32 kB |               2 |               0 |                    -- |                    -- |                    -- |        1(     0) refs |        1(     0) refs |                    -- |                    -- |                    -- |
           64925 |           32 kB |               2 |               1 |                    -- |                    -- |                    -- |        3(     1) refs |        1(     0) refs |                    -- |                    -- |                    -- |
           66870 |           32 kB |               2 |               1 |                    -- |                    -- |                    -- |        3(     1) refs |        1(     0) refs |                    -- |                    -- |                    -- |
           63994 |           16 kB |               2 |               0 |                    -- |                    -- |                    -- |        1(     0) refs |        1(     0) refs |                    -- |                    -- |                    -- |
           63995 |           16 kB |               2 |               0 |                    -- |                    -- |                    -- |        1(     0) refs |        1(     0) refs |                    -- |                    -- |                    -- |
           65906 |           32 kB |               2 |               0 |                    -- |                    -- |                    -- |        1(     0) refs |        1(     0) refs |                    -- |                    -- |                    -- |
           64933 |           16 kB |               2 |               0 |                    -- |                    -- |                    -- |        1(     0) refs |        1(     0) refs |                    -- |                    -- |                    -- |
           64932 |           32 kB |               2 |               0 |                    -- |                    -- |                    -- |        1(     0) refs |        1(     0) refs |                    -- |                    -- |                    -- |
           69198 |         4644 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |                    -- |
           73793 |         5072 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           53584 |           16 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           51802 |           16 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           66882 |           16 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           66879 |           16 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           64935 |           16 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           65914 |           16 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           65916 |           16 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           65918 |           16 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |                    -- |
           44867 |           68 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           44870 |           68 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           44872 |           68 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           51809 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           53586 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           52583 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           51811 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           62391 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           53598 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           62396 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           50076 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           62398 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           62400 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           50078 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           62523 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           62525 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           62527 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           62529 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           62402 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           62531 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
           62533 |           52 kB |               1 |               1 |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |                    -- |        1(     1) refs |
------------------------------------
TOTALS                    57932 kB |             n/a |             n/a |                144 kB |              32196 kB |              36356 kB |                304 kB |                304 kB |               9716 kB |              21268 kB |               1140 kB |

说明：

• Fd Ref Counts ：表示该FD有多少个进程在引用
• Map Ref Counts：表示该FD当前有多少个进程已经做过Map
• FD( Map) refs : 该进程持有该Buffer的参考计数的总数量以及Map的总次数

Dump整个系统DMA-BUF per-buffer, per-exporter and per-device statistics

在kernel版本>= 5.10上生效。

执行:

dmabuf_dump -b

会从sysfs(/sys/kernel/dmabuf/buffers)中dump dmabuf统计信息，显示如下内容：

----------------------- DMA-BUF per-buffer stats -----------------------
    Dmabuf Inode |     Size(bytes) |             Exporter Name             |
           29038 |        17051648 |       virtio_gpu
           39778 |            4096 |           system
           51377 |            4096 |           system
           52436 |          487424 |       virtio_gpu
           52766 |           45056 |       virtio_gpu
           16692 |        17051648 |       virtio_gpu
           50891 |        17051648 |       virtio_gpu
           39786 |            4096 |           system
           39748 |          155648 |       virtio_gpu
           52774 |           45056 |       virtio_gpu
           52529 |            4096 |           system
           51337 |           12288 |       virtio_gpu
           52764 |           45056 |       virtio_gpu
           16690 |        17051648 |       virtio_gpu
           39784 |            4096 |           system
           39746 |          155648 |       virtio_gpu
           52772 |           45056 |       virtio_gpu
           52762 |            4096 |           system
           51486 |            4096 |           system
           39792 |            4096 |           system
           39754 |          155648 |       virtio_gpu
           39782 |            4096 |           system
           50727 |         5783552 |       virtio_gpu
           57870 |            4096 |           system
           52770 |           45056 |       virtio_gpu
           51371 |            4096 |           system
           57832 |            4096 |           system
           57597 |          487424 |       virtio_gpu
           51484 |            4096 |           system
           50735 |            4096 |           system
           29040 |        17051648 |       virtio_gpu
           39752 |          155648 |       virtio_gpu
           39780 |            4096 |           system
           57869 |          970752 |       virtio_gpu
           52769 |            4096 |           system
           57595 |          487424 |       virtio_gpu
           16695 |            4096 |           system
           50733 |            4096 |           system
           29039 |            4096 |           system
           39750 |          155648 |       virtio_gpu
           39779 |          155648 |       virtio_gpu
           52437 |            4096 |           system
           52767 |            4096 |           system
           51490 |        17051648 |       virtio_gpu
           57593 |          487424 |       virtio_gpu
           16693 |            4096 |           system
           50892 |            4096 |           system
           39787 |          155648 |       virtio_gpu
           39749 |            4096 |           system
           52775 |            4096 |           system
           39777 |          155648 |       virtio_gpu
           51376 |           12288 |       virtio_gpu
           51338 |            4096 |           system
           52765 |            4096 |           system
           16691 |            4096 |           system
           39785 |          155648 |       virtio_gpu
           39747 |            4096 |           system
           52773 |            4096 |           system
           52528 |         3776512 |       virtio_gpu
           39755 |            4096 |           system
           39783 |          155648 |       virtio_gpu
           50728 |            4096 |           system
           52771 |            4096 |           system
           57598 |            4096 |           system
           52761 |          970752 |       virtio_gpu
           39310 |            4096 |           system
           51485 |        17051648 |       virtio_gpu
           39791 |          155648 |       virtio_gpu
           29041 |            4096 |           system
           39753 |            4096 |           system
           39781 |          155648 |       virtio_gpu
           39620 |            4096 |           system
           51370 |           12288 |       virtio_gpu
           57831 |          970752 |       virtio_gpu
           57596 |            4096 |           system
           39309 |         5783552 |       virtio_gpu
           51483 |        17051648 |       virtio_gpu
           50734 |         5783552 |       virtio_gpu
           39751 |            4096 |           system
           39619 |        17051648 |       virtio_gpu
           52768 |           45056 |       virtio_gpu
           51491 |            4096 |           system
           57594 |            4096 |           system
           16694 |        17051648 |       virtio_gpu
           39788 |            4096 |           system
           50732 |         5783552 |       virtio_gpu

----------------------- DMA-BUF exporter stats -----------------------
      Exporter Name              | Total Count |     Total Size(bytes)   |
                      virtio_gpu |           43| 204464128
                          system |           43| 176128

----------------------- DMA-BUF total stats --------------------------
Total DMA-BUF count: 86, Total DMA-BUF size(bytes): 204640256

DMA-BUF 驱动

代码位置：android/kernel/msm-5.4/drivers/dma-buf/