Public bug reported: After upgrading my Raspberry Pi 4 from Eoan to Focal (arm64), it now runs awfully slow with dmesg showing loooooots of these warnings:
[ 3821.602211] ------------[ cut here ]------------ [ 3821.603018] WARNING: CPU: 2 PID: 25391 at drivers/mmc/host/sdhci.c:1101 sdhci_prepare_data+0x3dc/0x7b0 [ 3821.603805] Modules linked in: md4 nls_utf8 cifs libdes libarc4 fscache btsdio bluetooth ecdh_generic ecc bcm2835_v4l2(CE) brcmfmac vc4 bcm2835_mmal_vchiq(CE) videobuf2_vmalloc drm_kms_helper brcmutil videobuf2_memops cfg80211 videobuf2_v4l2 snd_soc_core videobuf2_common videodev snd_compress ac97_bus mc snd_pcm_dmaengine snd_pcm snd_timer snd fb_sys_fops vc_sm_cma(CE) syscopyarea sysfillrect raspberrypi_hwmon sysimgblt rpivid_mem uio_pdrv_genirq uio crct10dif_ce sch_fq_codel drm ip_tables x_tables autofs4 phy_generic [ 3821.607749] CPU: 2 PID: 25391 Comm: kworker/2:1H Tainted: G WC E 5.4.0-1011-raspi #11-Ubuntu [ 3821.608526] Hardware name: Raspberry Pi 4 Model B Rev 1.1 (DT) [ 3821.609298] Workqueue: kblockd blk_mq_run_work_fn [ 3821.610059] pstate: a0400085 (NzCv daIf +PAN -UAO) [ 3821.610820] pc : sdhci_prepare_data+0x3dc/0x7b0 [ 3821.611579] lr : sdhci_prepare_data+0x2cc/0x7b0 [ 3821.612338] sp : ffff80001063b9b0 [ 3821.613105] x29: ffff80001063b9b0 x28: ffff0000ecb7b800 [ 3821.613890] x27: 0000000000000002 x26: 0000000000000000 [ 3821.614670] x25: ffff0000f63a7000 x24: ffff0000f63a7580 [ 3821.615448] x23: 0000000000418958 x22: ffff0000ecbf01d8 [ 3821.616268] x21: ffff0000f3599dc0 x20: ffff0000ecbf0258 [ 3821.617128] x19: ffff0000f63a7580 x18: 0000000000000000 [ 3821.617934] x17: 0000000000000000 x16: 0000000000000000 [ 3821.618777] x15: 0000000000000000 x14: df7a1aa12be812e6 [ 3821.619567] x13: 000000000038fe30 x12: 4b956d3506ed8169 [ 3821.620348] x11: 000000000038fd88 x10: d75619a60c149ecb [ 3821.621125] x9 : 000000000038fce8 x8 : 8ca0b852b1c7c8e1 [ 3821.621897] x7 : 000000000038fbb0 x6 : ffffa00671009a44 [ 3821.622671] x5 : ffffffffffffffff x4 : 0000000000000020 [ 3821.623445] x3 : 0000000000000001 x2 : 0000000000000000 [ 3821.624219] x1 : ffff0000ecbea000 x0 : 00000000ffffffe4 [ 3821.624993] Call trace: [ 3821.625756] sdhci_prepare_data+0x3dc/0x7b0 [ 3821.626523] sdhci_send_command+0xe0/0x5f0 [ 3821.627289] sdhci_request+0x110/0x150 [ 3821.628054] __mmc_start_request+0x88/0x1a8 [ 3821.628819] mmc_start_request+0x98/0xc0 [ 3821.629585] mmc_blk_mq_issue_rq+0x30c/0x778 [ 3821.630351] mmc_mq_queue_rq+0x14c/0x320 [ 3821.631118] blk_mq_dispatch_rq_list+0xa4/0x5f8 [ 3821.631888] blk_mq_do_dispatch_sched+0x68/0x108 [ 3821.632659] blk_mq_sched_dispatch_requests+0x164/0x1c0 [ 3821.633431] __blk_mq_run_hw_queue+0xfc/0x158 [ 3821.634200] blk_mq_run_work_fn+0x28/0x38 [ 3821.634970] process_one_work+0x1d0/0x430 [ 3821.635737] worker_thread+0x54/0x4a0 [ 3821.636505] kthread+0xfc/0x128 [ 3821.637272] ret_from_fork+0x10/0x1c [ 3821.638039] ---[ end trace bbce8914f99b8e25 ]--- syslog and kern.log fill up with these messages to hundreds of megabytes in an hour. This is with kernel 5.4.0.1011.11 . The green "SD activity" LED is constantly lit. ** Affects: linux-raspi (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1880607 Title: Raspberry Pi 4 extremely slow file i/o after upgrade to 20.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-raspi/+bug/1880607/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs