linux low IO performance on /dev/ram ?!? - Page 1
Forum section: electronics / general

author: legacy
author_rank: Super Contributor
timestamp: February 28, 2018, 11:14:23 pm
content: Code:dd if=/dev/zero of=/dev/ram0 bs=1k count=40004000+0 records in4000+0 records out4096000 bytes (3.9MB) copied, 0.736300 seconds, 5.3MB/s/dev/ram0 is ram, PC133 SDRAM! And the CPU is 266Mhz, how can IO performance on a RAM disk can be so ... slow?What can be wrong? (there is no bus, no DMA, in the middle)

author: legacy
author_rank: Super Contributor
timestamp: February 28, 2018, 11:15:41 pm
content: linux-4.11Code:~ # cat /proc/cpuinfoprocessor : 0cpu : 405GPclock : 266.640000MHzrevision : 1.69 (pvr 4011 0145)bogomips : 533.28timebase : 266640000Memory : 48 MB

author: legacy
author_rank: Super Contributor
timestamp: February 28, 2018, 11:24:21 pm
content: (it's a PowerPC 405GP by IBM/AMCC, the core is similar to a PPC603)

author: westfw
author_rank: Super Contributor
timestamp: March 01, 2018, 03:44:12 am
content: Is /dev/ram SUPPOSED to be a high-performance interface? I would have guessed (without any actual knowledge) a sort of raw access to ramdisk from user space, probably involving multiple context switches and pager remapping for each block (or even for each byte...) All the higher performance code would be stuck in the higher level drivers. Sort-of like trying to access a hard drive with a "read sector" API.

author: llkiwi2006
author_rank: Regular Contributor
timestamp: March 01, 2018, 03:57:21 am
content: What is the performance like on a tmpfs? /dev/ram isn't used that much anymore. Also, try with a bigger block size, you might be limited by the CPU's performance.

author: helius
author_rank: Super Contributor
timestamp: March 01, 2018, 04:35:37 am
content: Suggest you monitor the process with iostat

author: hans
author_rank: Super Contributor
timestamp: March 01, 2018, 09:25:57 am
content: Well, what figures do you actually expect to get?I think 5MB/s on so much overhead is actually very respectable. Note that /dev/mem is a character device, so it must go through all the device driver layers, before it can finally commit the write.If you want faster performance, I suppose you need to escape the user land.

author: legacy
author_rank: Super Contributor
timestamp: March 01, 2018, 10:17:10 am
content: I was expecting 20 Mbyte/sec at least since it's a block of ram pre-allocated in an area that the kernel can't use for anything else.I am experimenting the same kind of problem with a special block-device I have created recycling the MTD's code. It's a true-ram-disk used to store the rootfs, but it gives 3Mbyte/sec

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: March 01, 2018, 10:34:31 am
content: IDK, but for comparison, look:Code:pi@xu4:~$ sudo dd if=/dev/zero of=/dev/ram0 bs=1k count=4000 password for pi:4000+0 records in4000+0 records out4096000 bytes (4.1 MB) copied, 0.0402256 s, 102 MB/sCode:pi@bananapi:~$ sudo dd if=/dev/zero of=/dev/ram0 bs=1k count=4000 password for pi:4000+0 records in4000+0 records out4096000 bytes (4.1 MB) copied, 0.0706718 s, 58.0 MB/sCode:pi@odroidc1:~$ sudo dd if=/dev/zero of=/dev/ram0 bs=1k count=4000 password for pi:4000+0 records in4000+0 records out4096000 bytes (4.1 MB) copied, 0.0324672 s, 126 MB/sCode:pi@orangepipc:~$ sudo dd if=/dev/zero of=/dev/ram0 bs=1k count=4000 password for pi:4000+0 records in4000+0 records out4096000 bytes (4.1 MB) copied, 0.0309904 s, 132 MB/s

author: legacy
author_rank: Super Contributor
timestamp: March 01, 2018, 11:05:34 am
content: yes, there is something wrong with my kernel!/dev/ram0 is not /dev/mem, and it' a true block-device!the problem is WTF is wrong?!?!?

author: legacy
author_rank: Super Contributor
timestamp: March 01, 2018, 11:24:12 am
content: The PPC405GP comes with a Synchronous DRAM (SDRAM) interface operating up to 133MHzand it's 32-bit interface for non-ECC applicationsCan't be so slow!!!The kernel was (cross-)compiled with powerpc-unknown-linux-gnu-v4.2.4 ...I wonder ... if it needs some special "flags", but PPC405GB should be a true-PPC603 core

author: donotdespisethesnake
author_rank: Super Contributor
timestamp: March 01, 2018, 11:32:18 am
content: Sounds like you've never used software before

author: legacy
author_rank: Super Contributor
timestamp: March 01, 2018, 12:12:38 pm
content: Quote from: donotdespisethesnake on March 01, 2018, 11:32:18 amsure, I a porn-actor

author: legacy
author_rank: Super Contributor
timestamp: March 01, 2018, 12:15:36 pm
content: I have changed the cross-builder's profile and I am building a new gcc-toolchain with "-m405", that (I hope) should force gcc to be ppc405-optimizedI am open to better advice! ( I am more an HDL-guy than a linux-guy )

author: legacy
author_rank: Super Contributor
timestamp: March 01, 2018, 01:19:00 pm
content: Code:mount -t tmpfs /mnt/disk0/ /mnt/disk0/rm /root/hereuc-walnut-earlyrootfs disk0 # dd if=/dev/zero of=/mnt/disk0/here bs=1k count=50005000+0 records in5000+0 records out5120000 bytes (4.9MB) copied, 0.530093 seconds, 9.2MB/s

author: Bruce Abbott
author_rank: Frequent Contributor
timestamp: March 01, 2018, 05:30:29 pm
content: Quote from: legacy on March 01, 2018, 01:19:00 pmWhat happens if you increase the block size?For reference, here are the results for different buffer sizes on my ancient 50MHz Amiga 1200:-Code:Device:ram:CommentA1200 with Blizzard 1230-50 MKII (50MHz 68030)Test Intensity: High Performance Stress: None147 Files/s Create249 Files/s Open/Close1620 Files/s Scan279 Files/s Delete688 Seek/ReadBuffer Size512409632768262144---------------------------------------------Bytes/s Create582605135573416318261672495Bytes/s Write8288244391582941878711012736Bytes/s Read8377694449206964438711302545Faster than a 266MHz PPC with PC133 SDRAM!

author: legacy
author_rank: Super Contributor
timestamp: March 01, 2018, 07:07:33 pm
content: Quote from: Bruce Abbott on March 01, 2018, 05:30:29 pmtmpfs stays around 9Mbyte/sec/dev/ram0 stays around 4.5Mbyte/secI can't understand why the PPC405GP's ram controller (built-in) is so slow.I have re-created the toolchain, and gcc is now using a special flag for the 405GP, but .. it's still slow.

author: legacy
author_rank: Super Contributor
timestamp: March 01, 2018, 07:08:51 pm
content: oh, tried kernels from 2.6.22 to 2.6.39, and then the 4.11there is no difference

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: March 01, 2018, 07:33:17 pm
content: An OrangePi PC is only $15 :-)

author: Monkeh
author_rank: Super Contributor
timestamp: March 01, 2018, 07:37:16 pm
content: Quote from: GeorgeOfTheJungle on March 01, 2018, 07:33:17 pmAs his name implies, he's allergic to any technology developed in the 21st century.

author: legacy
author_rank: Super Contributor
timestamp: March 01, 2018, 07:44:56 pm
content: Quote from: Monkeh on March 01, 2018, 07:37:16 pmI have a product based on PowerPC405GP, and I can't change it.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: March 01, 2018, 07:59:04 pm
content: Quote from: legacy on March 01, 2018, 07:44:56 pmOh ohhh. Good luck then.

author: langwadt
author_rank: Super Contributor
timestamp: March 01, 2018, 08:08:01 pm
content: Quote from: legacy on March 01, 2018, 07:44:56 pmtried from a c program?

author: nctnico
author_rank: Super Contributor
timestamp: March 01, 2018, 08:09:39 pm
content: I'd look for some kind of rogue (kernel) process or driver eating up all the CPU time.

author: legacy
author_rank: Super Contributor
timestamp: March 01, 2018, 08:14:21 pm
content: Quote from: nctnico on March 01, 2018, 08:09:39 pmI personally wrote the rootfs, and the bootstrap scripts. Once the kernel is loaded and booted, it loads /sbin/init, that loads sshd, and the bash shell.you have a bash shell connected to the console (/dev/ttyS0, serial line), and a remote ssh shell.there is nothing else launched!which kind of rouge (kernel) process? and how to investigate?

author: legacy
author_rank: Super Contributor
timestamp: March 01, 2018, 08:15:52 pm
content: "top" saysCode:CPU: 0.0% usr 0.5% sys 0.0% nic 99.4% idle 0.0% io 0.0% irq 0.0% sirqLoad average: 0.00 0.01 0.12 1/30 1194

author: nctnico
author_rank: Super Contributor
timestamp: March 01, 2018, 10:55:45 pm
content: One way to find out is to create a program which toggles an I/O pin without writing to /tmpfs and one with writing to /tmpfs. That way you can see if there is something wrong in general or there is a filesystem problem.I guess any kind of swap space (virtual memory) is disabled? Any dmesg output?

author: legacy
author_rank: Super Contributor
timestamp: March 01, 2018, 11:03:40 pm
content: Quote from: nctnico on March 01, 2018, 10:55:45 pmenabled, not usedQuote from: nctnico on March 01, 2018, 10:55:45 pmCode:kernelinfo compiled by root@OrangeCubekernelinfo compiled with gcc version 4.2.4 (Gentoo 4.2.4-r1 p1.4)kernelinfo compiled ticket #226 Thu Mar 1 21:47:26 CET 2018Found legacy serial port 0 for /plb/opb/serial@ef600300mem=ef600300, taddr=ef600300, irq=0, clk=11110000, speed=9600Found legacy serial port 1 for /plb/opb/serial@ef600400mem=ef600400, taddr=ef600400, irq=0, clk=11110000, speed=9600Top of RAM: 0x3000000, Total RAM: 0x3000000Memory hole size: 0MBZone PFN ranges:DMA 0x00000000 -> 0x00003000Normal emptyHighMem emptyMovable zone start PFN for each nodeearly_node_map active PFN ranges0: 0x00000000 -> 0x00003000On node 0 totalpages: 12288free_area_init_node: node 0, pgdat c0472178, node_mem_map c04b7000DMA zone: 96 pages used for memmapDMA zone: 0 pages reservedDMA zone: 12192 pages, LIFO batch:1MMU: Allocated 1088 bytes of context maps for 255 contextspcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768pcpu-alloc:  0Built 1 zonelists in Zone order, mobility grouping on. Total pages: 12192Kernel command line: console=ttyS0,9600 mem=48M rdinit=/sbin/init pci=assign-busses pci=nobios root=/dev/mtdblock1 rw init=/sbin/init video=matroxfb:vesa:0x11B,mem:4M,pciretry,nobiosPID hash table entries: 256 (order: -2, 1024 bytes)Dentry cache hash table entries: 8192 (order: 3, 32768 bytes)Inode-cache hash table entries: 4096 (order: 2, 16384 bytes)High memory: 0kMemory: 43808k/49152k available (4448k kernel code, 5344k reserved, 148k data, 222k bss, 172k init)Kernel virtual memory layout:* 0xfffcf000..0xfffff000 : fixmap* 0xff800000..0xffc00000 : highmem PTEs* 0xff600000..0xff800000 : consistent mem* 0xff600000..0xff600000 : early ioremap* 0xc4000000..0xff600000 : vmalloc & ioremapSLUB: Genslabs=13, HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1NR_IRQS:512 nr_irqs:512 16UIC0 (32 IRQ sources) at DCR 0xc0time_init: decrementer frequency = 266.640000 MHztime_init: processor frequency = 266.640000 MHzclocksource: timebase mult shift registeredclockevent: decrementer mult shift cpuConsole: colour dummy device 80x25pid_max: default: 32768 minimum: 301Mount-cache hash table entries: 512devtmpfs: initializedNET: Registered protocol family 16PCI host bridge /plb/pci@ec000000 (primary) ranges:MEM 0x0000000080000000..0x000000009fffffff -> 0x0000000080000000IO 0x00000000b0000000..0x00000000b000ffff -> 0x00000000000000004xx PCI DMA offset set to 0x00000000PCI: Probing PCI hardwarepci_bus 0000:00: scanning buspci 0000:00:00.0: [1014:0156] type 0 class 0x000600pci 0000:00:00.0: calling quirk_mmio_always_on+0x0/0x24pci 0000:00:00.0: reg 14: [mem 0x00000000-0x7fffffff pref]pci 0000:00:00.0: calling pcibios_fixup_resources+0x0/0xe0pci 0000:00:00.0: calling fixup_ppc4xx_pci_bridge+0x0/0x11cPCI: Hiding 4xx host bridge resources 0000:00:00.0pci 0000:00:00.0: calling quirk_resource_alignment+0x0/0x184pci 0000:00:00.0: supports D1pci 0000:00:04.0: [105a:0d30] type 0 class 0x000101pci 0000:00:04.0: calling quirk_mmio_always_on+0x0/0x24pci 0000:00:04.0: reg 10: [io 0x01f0-0x01ff]pci 0000:00:04.0: reg 14: [io 0x03f4-0x03f7]pci 0000:00:04.0: reg 18: [io 0x0170-0x017f]pci 0000:00:04.0: reg 1c: [io 0x0374-0x0377]pci 0000:00:04.0: reg 20: [io 0x83fa40-0x83fa7f]pci 0000:00:04.0: reg 24: [mem 0x80000000-0x8001ffff]pci 0000:00:04.0: reg 30: [mem 0x000dc000-0x000dffff pref]pci 0000:00:04.0: calling pcibios_fixup_resources+0x0/0xe0pci 0000:00:04.0: calling fixup_ppc4xx_pci_bridge+0x0/0x11cpci 0000:00:04.0: calling quirk_resource_alignment+0x0/0x184pci_bus 0000:00: fixups for busirq: irq 31 on host /interrupt-controller mapped to virtual irq 31pci_bus 0000:00: bus scan returning with max=00pci 0000:00:04.0: BAR 5: assigned [mem 0x80000000-0x8001ffff]pci 0000:00:04.0: BAR 5: set to [mem 0x80000000-0x8001ffff] (PCI address [0x80000000-0x8001ffff])pci 0000:00:04.0: BAR 6: assigned [mem 0x80020000-0x80023fff pref]pci 0000:00:04.0: BAR 4: assigned [io 0x1000-0x103f]pci 0000:00:04.0: BAR 4: set to [io 0x1000-0x103f] (PCI address [0x1000-0x103f])pci_bus 0000:00: resource 0 [io 0x0000-0xffff]pci_bus 0000:00: resource 1 [mem 0x80000000-0x9fffffff]bio: create slab <bio-0> at 0SCSI subsystem initializedlibata version 3.00 loaded.usbcore: registered new interface driver usbfsusbcore: registered new interface driver hubusbcore: registered new device driver usbSwitching to clocksource timebaseNET: Registered protocol family 2IP route cache hash table entries: 1024 (order: 0, 4096 bytes)TCP established hash table entries: 2048 (order: 2, 16384 bytes)TCP bind hash table entries: 2048 (order: 1, 8192 bytes)TCP: Hash tables configured (established 2048 bind 2048)TCP reno registeredUDP hash table entries: 256 (order: 0, 4096 bytes)UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)NET: Registered protocol family 1pci 0000:00:00.0: calling quirk_cardbus_legacy+0x0/0x44pci 0000:00:00.0: calling quirk_usb_early_handoff+0x0/0x5f0pci 0000:00:04.0: calling quirk_cardbus_legacy+0x0/0x44pci 0000:00:04.0: calling quirk_usb_early_handoff+0x0/0x5f0PCI: CLS 0 bytes, default 32irq: irq 0 on host /interrupt-controller mapped to virtual irq 16irq: irq 1 on host /interrupt-controller mapped to virtual irq 17irq: irq 11 on host /interrupt-controller mapped to virtual irq 18irq: irq 12 on host /interrupt-controller mapped to virtual irq 19irq: irq 10 on host /interrupt-controller mapped to virtual irq 20irq: irq 13 on host /interrupt-controller mapped to virtual irq 21irq: irq 14 on host /interrupt-controller mapped to virtual irq 22irq: irq 2 on host /interrupt-controller mapped to virtual irq 23irq: irq 15 on host /interrupt-controller mapped to virtual irq 24irq: irq 9 on host /interrupt-controller mapped to virtual irq 25OF_RTC: /plb/ebc/nvram@1,0 is a rtc-ds1742 @ 0xf0000000-0xf0001fffmsgmni has been set to 85Block layer SCSI generic (bsg) driver version 0.4 loaded (major 254)io scheduler noop registeredio scheduler deadline registered (default)io scheduler cfq registeredSerial: 8250/16550 driver, 4 ports, IRQ sharing enabledserial8250.0: ttyS0 at MMIO 0xef600300 (irq = 16) is a 16550Aconsole  enabledserial8250.0: ttyS1 at MMIO 0xef600400 (irq = 17) is a 16550Aef600300.serial: ttyS0 at MMIO 0xef600300 (irq = 16) is a 16550ef600400.serial: ttyS1 at MMIO 0xef600400 (irq = 17) is a 16550brd: module loadedloop: module loadednbd: registered device at major 43Found: AMD AM29LV040Bfff80000.flash: Found 1 x8 devices at 0x0 in 8-bit banknumber of JEDEC chips: 1myramfs: devname=myramfs, devstart=0x3000000, devlength=0x4000000myramfs: Registered device myramfs from 49152KiB to 114688KiBmyramfs: Mapped from 0xc4180000 to 0xc8180000myramswap: devname=myramswap, devstart=0x7000000, devlength=0x1000000myramswap: Registered device myramswap from 114688KiB to 131072KiBmyramswap: Mapped from 0xc8200000 to 0xc9200000PPC 4xx OCP EMAC driver, version 3.54MAL v1 /plb/mcmal, 1 TX channels, 1 RX channelseth0: EMAC-0 /plb/opb/ethernet@ef600800, MAC de:00:b1:ef:ae:a3eth0: found Generic MII PHY (0x09)aoe: AoE v47 initialised.ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Drivermousedev: PS/2 mouse device common for all miceI2O subsystem v1.325i2o: max drivers = 8I2O ProcFS OSM v1.316i2c /dev entries driveribm-iic ef600500.i2c: using standard (100 kHz) modeusbcore: registered new interface driver usbhidusbhid: USB HID core driverIPv4 over IPv4 tunneling driverTCP bic registeredTCP cubic registeredTCP westwood registeredTCP highspeed registeredTCP hybla registeredTCP htcp registeredTCP vegas registeredTCP veno registeredTCP scalable registeredTCP lp registeredTCP yeah registeredTCP illinois registeredNET: Registered protocol family 10IPv6 over IPv4 tunneling driverNET: Registered protocol family 17NET: Registered protocol family 15802.1Q VLAN SupportVFS: Mounted root (ext2 filesystem) on device 31:1.devtmpfs: mountedFreeing unused kernel memory: 172k inituserland initeth0: link is up, 100 FDX, pause enabled

author: legacy
author_rank: Super Contributor
timestamp: March 01, 2018, 11:09:35 pm
content: Code:myramfs: devname=myramfs, devstart=0x3000000, devlength=0x4000000myramfs: Registered device myramfs from 49152KiB to 114688KiBmyramfs: Mapped from 0xc4180000 to 0xc8180000Code:myramswap: devname=myramswap, devstart=0x7000000, devlength=0x1000000myramswap: Registered device myramswap from 114688KiB to 131072KiBmyramswap: Mapped from 0xc8200000 to 0xc9200000these two kernel-modules are physical ram handlers.in the dmesg:- myramswap (/dev/myramdev2) has allocated ram, the MMU can't touch it, but it's not used.- myramfs (/dev/myramdev1) has allocated ram, the MMU can't touch it, and it's used as ram-rootfs.Code:/dev/myramdev1 on / type ext2 (rw)mpme on /dev/pts type devpts (rw)/mnt/disk0 on /var type none (rw,bind)/var/tmp on /tmp type none (rw,bind)

author: Bruce Abbott
author_rank: Frequent Contributor
timestamp: March 02, 2018, 05:20:35 pm
content: Quote from: legacy on March 01, 2018, 07:07:33 pmIs there some other test you can do to measure the SDRAM speed (eg. create a large array and read data from it)?QuoteSDRAM controller properly initialized? Data cache enabled?

author: legacy
author_rank: Super Contributor
timestamp: March 02, 2018, 06:42:07 pm
content: Quote from: Bruce Abbott on March 02, 2018, 05:20:35 pmCode:~ # ramspeed -b3 -m2RAMspeed/SMP (GENERIC) v3.5.0 by Rhett M. Hollander and Paul V. Bolotoff, 2002-098Gb per pass mode, 2 processesINTEGER Copy: 104.74 MB/sINTEGER Scale: 99.29 MB/sINTEGER Add: 86.03 MB/sQuote from: Bruce Abbott on March 02, 2018, 05:20:35 pmThat is hard to be verified at the moment since it involves both the firmware and the kernel.uboot on bootstrap saysCode:U-Boot 1.2.0 (Nov 7 2010 - 18:54:57)CPU: AMCC PowerPC 405GP Rev. E at 266.640 MHz (PLB=66, OPB=33, EBC=33 MHz)Internal PCI arbiter enabled, PCI async ext clock used16 kB I-Cache 8 kB D-Cacheand the linux kernel doesn't say moremy doubt: if the devicetree has something to do with the correct re-initialization of the dram controller

author: Bruce Abbott
author_rank: Frequent Contributor
timestamp: March 03, 2018, 06:03:20 am
content: 104.74 MB/s when copying from one array to another indicates that your memory is fine. The fact that your ramdisk is slow and doesn't speed up with larger transfer sizes suggests a problem in the driver or how it was tested.Is there some way you can profile the code to find out what proportion of the time is spent in memory transfers to/from the ramdisk memory, and how much in other stuff?

author: legacy
author_rank: Super Contributor
timestamp: March 03, 2018, 06:53:16 am
content: Quote from: Bruce Abbott on March 03, 2018, 06:03:20 amthat is the question to be addressed to "linux experts". Anyone here?DENX's guys are not answering my emails (who? they were THE guys whose signature you can still find in Linux sources)

author: legacy
author_rank: Super Contributor
timestamp: March 03, 2018, 06:56:17 am
content: Code:dd if=/dev/zero of=10Mbyte bs=1k count=10000time cp 10Mbyte theretime says ~ 10Mbyte/sec on kernel 2.6.39 (it's around 0.99 sec), and 5Mbyte/sec on kernel 4.11 (it's around 1.99sec), and it's more interesting than the output of dd because it's a "true" application

author: VintageTekFan
author_rank: Regular Contributor
timestamp: March 03, 2018, 08:13:03 am
content: I am curious which I/O scheduler you are using. Some of them are optimized for high (relatively) latency devices.Typical choices are: NOOP, CFQ, Anticipatory, Deadline...A good read on them:https://www.safaribooksonline.com/library/view/linux-system-programming/0596009585/ch04s06.html

author: legacy
author_rank: Super Contributor
timestamp: March 03, 2018, 09:02:09 am
content: Quote from: VintageTekFan on March 03, 2018, 08:13:03 amkernel 2.6.39: Deadline IO schedulerkernel 4.11: Deadline IO scheduler

author: Bruce Abbott
author_rank: Frequent Contributor
timestamp: March 03, 2018, 07:46:37 pm
content: Quote from: legacy on March 03, 2018, 09:02:09 amTry NOOP.Choosing I/O SchedulingQuote

author: bson
author_rank: Unknown
timestamp: March 03, 2018, 11:35:40 pm
content: You might be getting large numbers of alignment traps, either in the kernel ram block device driver or dd.Even if the memory bus is 8-bit wide the PPCs still don't won't permit unaligned accesses, and those will trap into the kernel and get emulated. You can make them produce a SIGBUS for user space programs, see e.g. (it's been over 10 years since I had to track down similar problems so this may be out of date):https://www.kernel.org/doc/Documentation/arm/mem_alignmentVerify that your ram disk starts at an 8-byte alignment, although in reality the driver should page align it unless it's buggy.

author: legacy
author_rank: Super Contributor
timestamp: March 04, 2018, 11:39:17 am
content: Quote from: bson on March 03, 2018, 11:35:40 pmI will investigate, but ... on kernel 2.6.39? kernel 4.11? shouldn't they be a bit "modern"- enough to have those problems already fixed?