Xubuntu 16.04.1 alto uso de CPU ao gravar em SSD

Question

Eu noto um uso muito alto da CPU quando faço, por exemplo, um teste de velocidade (da internet) ou baixo um arquivo. Tudo o que causa muita gravação no SSD causa um uso quase máximo da CPU no meu notebook.

Informações de hardware

SO

Xubuntu 16.04.1 (instalado há apenas uma semana e atualizado hoje)

uname -a :

Linux xiaolong-hp-pavilion 4.4.0-62-generic #83-Ubuntu SMP Wed Jan 18 14:10:15 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

Dispositivos PCI

Saída de lspci :

00:00.0 Host bridge: Intel Corporation Device 5904 (rev 02)
00:02.0 VGA compatible controller: Intel Corporation Device 5916 (rev 02)
00:04.0 Signal processing controller: Intel Corporation Skylake Processor Thermal Subsystem (rev 02)
00:14.0 USB controller: Intel Corporation Sunrise Point-LP USB 3.0 xHCI Controller (rev 21)
00:14.2 Signal processing controller: Intel Corporation Sunrise Point-LP Thermal subsystem (rev 21)
00:16.0 Communication controller: Intel Corporation Sunrise Point-LP CSME HECI (rev 21)
00:17.0 SATA controller: Intel Corporation Sunrise Point-LP SATA Controller [AHCI mode] (rev 21)
00:1c.0 PCI bridge: Intel Corporation Device 9d10 (rev f1)
00:1c.4 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port (rev f1)
00:1c.5 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port (rev f1)
00:1d.0 PCI bridge: Intel Corporation Device 9d18 (rev f1)
00:1d.3 PCI bridge: Intel Corporation Device 9d1b (rev f1)
00:1f.0 ISA bridge: Intel Corporation Device 9d58 (rev 21)
00:1f.2 Memory controller: Intel Corporation Sunrise Point-LP PMC (rev 21)
00:1f.3 Audio device: Intel Corporation Device 9d71 (rev 21)
00:1f.4 SMBus: Intel Corporation Sunrise Point-LP SMBus (rev 21)
01:00.0 3D controller: NVIDIA Corporation GM108M [GeForce 940MX] (rev a2)
02:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS522A PCI Express Card Reader (rev 01)
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101/2/6E PCI Express Fast/Gigabit Ethernet controller (rev 0a)
05:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter

Informações do HDD

A saída de sudo hdparm -I /dev/sda :

/dev/sda:

ATA device, with non-removable media
    Model Number:       SAMSUNG MZNTY256HDHP-000H1              
    Serial Number:      S2ZPNY0H905855      
    Firmware Revision:  MAT21H3Q
    Transport:          Serial, ATA8-AST, SATA 1.0a, SATA II Extensions, SATA Rev 2.5, SATA Rev 2.6, SATA Rev 3.0
Standards:
    Used: unknown (minor revision code 0x0039) 
    Supported: 10 9 8 7 6 5 
    Likely used: 10
Configuration:
    Logical     max current
    cylinders   16383   0
    heads       16  0
    sectors/track   63  0
    --
    LBA    user addressable sectors:  268435455
    LBA48  user addressable sectors:  500118192
    Logical  Sector size:                   512 bytes
    Physical Sector size:                  4096 bytes
    Logical Sector-0 offset:                  0 bytes
    device size with M = 1024*1024:      244198 MBytes
    device size with M = 1000*1000:      256060 MBytes (256 GB)
    cache/buffer size  = unknown
    Form Factor: less than 1.8 inch
    Nominal Media Rotation Rate: Solid State Device
Capabilities:
    LBA, IORDY(can be disabled)
    Queue depth: 32
    Standby timer values: spec'd by Standard, no device specific minimum
    R/W multiple sector transfer: Max = 16  Current = 16
    Advanced power management level: 254
    DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 *udma5 
         Cycle time: min=120ns recommended=120ns
    PIO: pio0 pio1 pio2 pio3 pio4 
         Cycle time: no flow control=120ns  IORDY flow control=120ns
Commands/features:
    Enabled Supported:
       *    SMART feature set
            Security Mode feature set
       *    Power Management feature set
       *    Write cache
       *    Look-ahead
       *    WRITE_BUFFER command
       *    READ_BUFFER command
       *    NOP cmd
       *    DOWNLOAD_MICROCODE
       *    Advanced Power Management feature set
       *    48-bit Address feature set
       *    Mandatory FLUSH_CACHE
       *    FLUSH_CACHE_EXT
       *    SMART error logging
       *    SMART self-test
       *    General Purpose Logging feature set
       *    64-bit World wide name
       *    IDLE_IMMEDIATE with UNLOAD
       *    WRITE_UNCORRECTABLE_EXT command
       *    {READ,WRITE}_DMA_EXT_GPL commands
       *    Segmented DOWNLOAD_MICROCODE
            unknown 119[6]
            unknown 119[8]
            unknown 119[9]
       *    Gen1 signaling speed (1.5Gb/s)
       *    Gen2 signaling speed (3.0Gb/s)
       *    Gen3 signaling speed (6.0Gb/s)
       *    Native Command Queueing (NCQ)
       *    Phy event counters
       *    READ_LOG_DMA_EXT equivalent to READ_LOG_EXT
       *    DMA Setup Auto-Activate optimization
            Device-initiated interface power management
            Asynchronous notification (eg. media change)
       *    Software settings preservation
            unknown 78[7]
            Device Sleep (DEVSLP)
       *    SMART Command Transport (SCT) feature set
       *    SCT Write Same (AC2)
       *    SCT Error Recovery Control (AC3)
       *    SCT Features Control (AC4)
       *    SCT Data Tables (AC5)
       *    reserved 69[3]
       *    DOWNLOAD MICROCODE DMA command
       *    WRITE BUFFER DMA command
       *    READ BUFFER DMA command
       *    Data Set Management TRIM supported (limit 8 blocks)
       *    Deterministic read ZEROs after TRIM
Security: 
    Master password revision code = 65534
        supported
    not enabled
    not locked
    not frozen
    not expired: security count
        supported: enhanced erase
    2min for SECURITY ERASE UNIT. 8min for ENHANCED SECURITY ERASE UNIT. 
Logical Unit WWN Device Identifier: 5002538d001d6d69
    NAA     : 5
    IEEE OUI    : 002538
    Unique ID   : d001d6d69
Device Sleep:
    DEVSLP Exit Timeout (DETO): 50 ms (drive)
    Minimum DEVSLP Assertion Time (MDAT): 30 ms (drive)
Checksum: correct

Sistema de arquivos

Saída de stat -f -c %T / :

ext2/ext3

Qual poderia ser o motivo e o que eu posso fazer sobre isso?

    

Answer 1

Eu não sei exatamente o que estava acontecendo, mas encontrei uma solução:

Eu tive que adicionar pcie_aspm=off à linha

GRUB_CMDLINE_LINUX_DEFAULT="quiet splashi"

resultando em:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splashi pcie_aspm=off"

Depois disso e instalando o driver da placa de vídeo Nvidia a partir do arquivo do driver baixado após parar lightdm , o problema desapareceu.

Não tenho certeza se o driver da Nvidia tinha algo a ver com isso, mas o parâmetro pcie também corrigiu o uso alto de CPU de systemd-journald , que estava registrando erros de pcie na camada física o tempo todo.

No entanto, eu li em outro lugar, que este parâmetro desativa algumas medidas de economia de energia. Provavelmente os dispositivos PCIe, o que é lamentável.