On an unrelated note(but since btrfs was thought to be a problem at some point), I've discovered that btrfs with zstd:5 (or worse zstd:15) can cause (at least) mouse cursor stuttering(like it was skipping frames), while zstd:1 doesn't(likely because of the low CPU usage during compression), regardless of how fast/many writes are happening on the SSD(2-6M/s with zstd:15, 38-50+M/s with zstd:1), apparently due to high CPU usage during the compression. (zstd unspecified means zstd:3 aka default)
Normal CPU usage by itself(eg. during compiling) doesn't cause such stuttering though. I've tested this on a Lenovo Ideapad Z575, 16G RAM, Kingston SSD SA400S37240G firmware SBFK71F1, and I've personally switched to zstd:1 ie. ``` diff --git a/fs/btrfs/zstd.c b/fs/btrfs/zstd.c index 6b9e29d050f3..02ffdb27c360 100644 --- a/fs/btrfs/zstd.c +++ b/fs/btrfs/zstd.c @@ -22,7 +22,7 @@ #define ZSTD_BTRFS_MAX_WINDOWLOG 17 #define ZSTD_BTRFS_MAX_INPUT (1 << ZSTD_BTRFS_MAX_WINDOWLOG) -#define ZSTD_BTRFS_DEFAULT_LEVEL 3 +#define ZSTD_BTRFS_DEFAULT_LEVEL 1 #define ZSTD_BTRFS_MAX_LEVEL 15 /* 307s to avoid pathologically clashing with transaction commit */ #define ZSTD_BTRFS_RECLAIM_JIFFIES (307 * HZ) ``` but zstd:1 in /etc/fstab should also work, unless using too old kernel that doesn't know about it (hence why I prefer using the patch anyway) -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1833281 Title: System freeze when memory is put on SWAP in Linux >4.10.x Status in Linux: Confirmed Status in linux package in Ubuntu: Confirmed Bug description: I'm reporting this since it's reproduceable the 70% of the time. Summary: In different circumstances, when the systems starts to swap out RAM memory, even small amounts, the system becomes completely unusuable and the screen freezes up, no mouse movement, no TTY access or SSH access can be made, only SYSRQ keys seem to do something (only reboot, so REISUB worked so far though, OOM is useless since the memory/swap is not even full) The I/O Disk led is stuck to 100% in ALL the following cases when this happens. So far: - This happens even when only ZRAM is enabled, and no swap partition is used. - Happens when ZSWAP is used with a swap partition - Happens also when a partition without zram or zswap is used - Maybe it's AMD specific? However, I'm not experiencing this on my laptop using the same tests. My laptop is an Intel one, while my desktop is an AMD Ryzen platform. Here are the specs: CPU: AMD Ryzen 5 1600 no OC GPU: AMD RX 580 8GB SSD: Crucial MX500 500GB MOBO: MSI B350M Grenade RAM: 8GB HyperX Kingston 2667Mhz Ubuntu version: 18.04 LTS, backports repo enabled Kernel version: 4.18.0-18, official ubuntu repo Bios settings: Default Additional info: Maybe I'm not 100% sure, but I noticed when using the 5.0.0-17 generic kernel, the lockups seem to still happen, but they recover eventually. Happened only a few times though... But will always be frozen for at least 30 seconds, differently from my intel laptop where those do occur. The SSD make is the same. I bought two of these, they got also the same amount of RAM. In my laptop those do not occur at all. Swapping memory even huge quantities like 1GB or more, do not produce any issues. Tests made: For testing this behaviour I tried: - Compiling the chromium-browser source code (takes up a lot of system RAM) - Used the "stress" command, using a specific amount of memory to decide how many it will be swapped, and here I noticed that even small quantities like a couple of megabytes will cause the system to freeze the 70% of the times Example: "stress --vm 1 --vm-bytes=7G" What should happen: I expect system slowdowns when swapping out memory since I do not have enough RAM, but unlikely when using Windows or my laptop with the same Linux version, not a completely unusuable environment. The swap partition is in both cases on an SSD. Reproduceability: 70% of the times Additional info again: I'm not sure this is due to any hardware failure, my SSD health is fine, as my CPU and RAM. As I said swapping in Windows works fine... --- ProblemType: Bug ApportVersion: 2.20.9-0ubuntu7.6 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: haru 2076 F.... pulseaudio /dev/snd/controlC2: haru 2076 F.... pulseaudio /dev/snd/controlC0: haru 2076 F.... pulseaudio CurrentDesktop: communitheme:ubuntu:GNOME DistroRelease: Ubuntu 18.04 IwConfig: enp24s0 no wireless extensions. lo no wireless extensions. MachineType: Micro-Star International Co., Ltd. MS-7A37 Package: linux (not installed) ProcFB: 0 amdgpudrmfb ProcKernelCmdLine: BOOT_IMAGE=/@/boot/vmlinuz-5.0.0-17-generic root=UUID=75d45574-7169-4653-aea3-9f95087f0806 ro rootflags=subvol=@ quiet splash vt.handoff=1 ProcVersionSignature: Ubuntu 5.0.0-17.18~18.04.1-generic 5.0.8 RelatedPackageVersions: linux-restricted-modules-5.0.0-17-generic N/A linux-backports-modules-5.0.0-17-generic N/A linux-firmware 1.173.6 RfKill: 0: hci0: Bluetooth Soft blocked: no Hard blocked: no Tags: bionic Uname: Linux 5.0.0-17-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: sudo video WifiSyslog: _MarkForUpload: True dmi.bios.date: 01/22/2019 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 1.K0 dmi.board.asset.tag: To be filled by O.E.M. dmi.board.name: B350M MORTAR (MS-7A37) dmi.board.vendor: Micro-Star International Co., Ltd. dmi.board.version: 1.0 dmi.chassis.asset.tag: To be filled by O.E.M. dmi.chassis.type: 4 dmi.chassis.vendor: Micro-Star International Co., Ltd. dmi.chassis.version: 1.0 dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1.K0:bd01/22/2019:svnMicro-StarInternationalCo.,Ltd.:pnMS-7A37:pvr1.0:rvnMicro-StarInternationalCo.,Ltd.:rnB350MMORTAR(MS-7A37):rvr1.0:cvnMicro-StarInternationalCo.,Ltd.:ct4:cvr1.0: dmi.product.family: To be filled by O.E.M. dmi.product.name: MS-7A37 dmi.product.sku: To be filled by O.E.M. dmi.product.version: 1.0 dmi.sys.vendor: Micro-Star International Co., Ltd. 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