Good Evening,
Recently some code changes were introduced in the Linux-Next tree that
has led to a warning bug.
The merge appears to have occurred on June 16, 2018, when
mm/workingset.c was converted over to use XArray.
The issue is occurring on both Tegra2 and Tegra3 processors.
On T2 processors it appears to just be a warning, but on T3 processors
it leads to serious issues with hung tasks.
The warning is as follows:
[10409.408904] ------------[ cut here ]------------
[10409.408912] WARNING: CPU: 0 PID: 38 at ./include/linux/xarray.h:53
workingset_eviction+0x14c/0x154
[10409.408915] Modules linked in: fuse cpufreq_userspace
cpufreq_powersave bnep qmi_wwan usbnet mii brcmfmac cfg80211 brcmutil
hci_uart btbcm st_gyro_spi st_sensors_spi cpcap_adc bluetooth
st_gyro_i2c st_gyro cpcap_pwrbutton st_sensors_i2c st_sensors ak8975
industrialio_triggered_buffer snd_soc_tegra20_i2s joydev
snd_soc_tegra_pcm bmp280_spi snd_soc_core bmp280_i2c bmp280
snd_pcm_dmaengine ac97_bus tegra_vde(C) snd_soc_tegra20_das
uio_pdrv_genirq uio sch_fq_codel ip_tables x_tables phy_mapphone_mdm6600
[10409.409005] CPU: 0 PID: 38 Comm: kswapd0 Tainted: G WC
4.18.0-rc1-next-20180621-00001-gecc0b99b72bc-dirty #55
[10409.409009] Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
[10409.409021] [<c0115a2c>] (unwind_backtrace) from [<c010ee40>]
(show_stack+0x20/0x24)
[10409.409032] [<c010ee40>] (show_stack) from [<c0a299f8>]
(dump_stack+0xb4/0xe0)
[10409.409044] [<c0a299f8>] (dump_stack) from [<c0134ef8>]
(__warn+0x104/0x11c)
[10409.409052] [<c0134ef8>] (__warn) from [<c0135048>]
(warn_slowpath_null+0x50/0x58)
[10409.409060] [<c0135048>] (warn_slowpath_null) from [<c02e0aa0>]
(workingset_eviction+0x14c/0x154)
[10409.409071] [<c02e0aa0>] (workingset_eviction) from [<c02c0cb8>]
(__remove_mapping+0x154/0x1f0)
[10409.409079] [<c02c0cb8>] (__remove_mapping) from [<c02c37a4>]
(shrink_page_list+0xa60/0x101c)
[10409.409087] [<c02c37a4>] (shrink_page_list) from [<c02c4558>]
(shrink_inactive_list+0x258/0x6ac)
[10409.409095] [<c02c4558>] (shrink_inactive_list) from [<c02c5150>]
(shrink_node_memcg+0x330/0x6a8)
[10409.409103] [<c02c5150>] (shrink_node_memcg) from [<c02c55c4>]
(shrink_node+0xfc/0x51c)
[10409.409110] [<c02c55c4>] (shrink_node) from [<c02c69b8>]
(kswapd+0x2f4/0x86c)
[10409.409118] [<c02c69b8>] (kswapd) from [<c01597d8>] (kthread+0x16c/0x174)
[10409.409125] [<c01597d8>] (kthread) from [<c01010b4>]
(ret_from_fork+0x14/0x20)
[10409.409129] Exception stack(0xedc6dfb0 to 0xedc6dff8)
[10409.409134] dfa0: 00000000
00000000 00000000 00000000
[10409.409140] dfc0: 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000
[10409.409145] dfe0: 00000000 00000000 00000000 00000000 00000013 00000000
[10409.409149] ---[ end trace 5258a39aad429bfe ]---
Very Respectfully,
Peter Geis
