[Letux-kernel] 2GB vs. 4GB Pyra RAM tests

Michael Mrozek EvilDragon at openpandora.org
Wed Jul 26 17:17:49 CEST 2017


Am Mittwoch, den 26.07.2017, 17:00 +0200 schrieb H. Nikolaus Schaller:

Well, yes. But when U-Boot loads the kernel, a LOT less is going on in
the system (not all hardware is initialized).

So if there really is some noise from somewhere, it could be it runs
more stable with less clockspeed.

> But please consider in a theory that boot problems/hangup is only
> seen
> in kernel. I always got working DRAM in U-Boot to load the kernel at
> default DRAM speed.
> 
> > 
> > > 
> > > > Hi,
> > > > finally I found enough undisturbed time to run the tests
> > > > I had planned for a long time.
> > > > 
> > > > I tested with a single SD card with Letux-Debian8.9-LXDE
> > > > rootfs and overwriting kernel/U-Boot as required by:
> > > > 
> > > > a) letux-4.13-rc2 standard kernel - http://download.goldelico.c
> > > > om/let
> > > > ux-kernel/letux-4.13-rc2/
> > > > b) letux-4.13-rc2 LPAE kernel - http://download.goldelico.com/l
> > > > etux-k
> > > > ernel/letux-4.13-rc2-lpae/
> > > > 
> > > > A) U-Boot with 2GB RAM config - http://download.goldelico.com/l
> > > > etux-u
> > > > -boot/Pyra+LC15/latest/
> > > > B) U-Boot with 4GB RAM config - http://download.goldelico.com/l
> > > > etux-u
> > > > -boot/Pyra+LC15-4GB/latest/
> > > > 
> > > > The 4GB EMIF config is here:
> > > > 
> > > > <http://git.goldelico.com/?p=gta04-uboot.git;a=blobdiff;f=board
> > > > /golde
> > > > lico/letux-
> > > > cortex15/lc15.c;h=280da2095da9a780475fe3d59e79d283b050f02d;hp=7
> > > > 09865c
> > > > be0f10d389634924d3b57c5731c184429;hb=0c5e26e7886ea7d2d934f65e2e
> > > > 6cbf15
> > > > a2b52bc8;hpb=be096ca0c2b204897b84c45e709511184b3a4059>
> > > > 
> > > > 1) 2GB Pyra (C22 + M04)
> > > > 2) 4GB Pyra (C48 + M28)
> > > > 
> > > > For each combination, I did try to boot, login and run
> > > > "memtester
> > > > 1500MB".
> > > > memtester 3000MB is rejected for 2GB modes of course.
> > > > 
> > > > Here are the results:
> > > > 
> > > > Aa1)	2GB RAM visible, everything ok, memtester 1500M
> > > > successful
> > > > Aa2)	2GB RAM visible, boot sometimes hangs, memtester
> > > > 1500M
> > > > successful
> > > > Ab1)	2GB RAM visible, everything ok, memtester 1500M
> > > > successful
> > > > Ab2)	2GB RAM visible, boot sometimes hangs, memtester
> > > > 1500M
> > > > successful
> > > > Ba1)	U-Boot rejects device (SDRAM: identified size not
> > > > same as
> > > > expected)
> > > > Ba2)	2GB RAM visible, boot sometimes hangs, memtester
> > > > 1500M
> > > > successful
> > > > Bb1)	U-Boot rejects device (SDRAM: identified size not
> > > > same as
> > > > expected)
> > > > Bb2)	4GB RAM visible, boot more often hangs, memtester
> > > > 1500M
> > > > successful,
> > > > 	memtester 3000M sometimes hangs after requesting 3GB,
> > > > sometimes
> > > > successful
> > > > 
> > > > Now comes the difficult interpretation.
> > > > * generally this 4GB Pyra is less stable. Could be RAM induced
> > > > or something else. The test does not give a clear indication.
> > > > * the 2GB Pyra runs stable in all configurations
> > > > * 4GB and LPAE makes Linux boot fail more often
> > > > * it is possible to use the complete 4GB RAM, but not reliably
> > > > 
> > > > So I suspect a mixture of multiple effects. One makes the 4GB
> > > > device I have tested less stable.
> > > > 
> > > > And the other could be an LPAE issue that makes 4GB only
> > > > useable
> > > > in certain good cases (I could imagine it depends on how the
> > > > virtual paging mechanism randomly allocates RAM). But it could
> > > > still be the 4GB RAM chips or config being less stable due to
> > > > higher noise or power consumption or whatever.
> > > > 
> > > > Attached is an excerpt of the boot log and successful 3GB
> > > > memtester
> > > > output (the "BUG" occurs for non-lpae kernel as well - so it is
> > > > not
> > > > influencing the outcome).
> > > > 
> > > > BR,
> > > > Nikolaus
> > > > 
> > > > 
> > > > Starting kernel ...
> > > > 
> > > > [    0.000000] Booting Linux on physical CPU 0x0
> > > > [    0.000000] Linux version 4.13.0-rc2-letux-lpae+ (hns at iMac.l
> > > > ocal)
> > > > (gcc version 4.9.2 (GCC)) #1297 SMP PREEMPT Mon Jul 24 13:08:10
> > > > CEST
> > > > 2017
> > > > [    0.000000] CPU: ARMv7 Processor [412fc0f2] revision 2
> > > > (ARMv7),
> > > > cr=30c5387d
> > > > [    0.000000] CPU: div instructions available: patching
> > > > division
> > > > code
> > > > [    0.000000] CPU: PIPT / VIPT nonaliasing data cache, PIPT
> > > > instruction cache
> > > > [    0.000000] OF: fdt: Machine model: Pyra-Handheld-V5.1
> > > > [    0.000000] debug: ignoring loglevel setting.
> > > > [    0.000000] Memory policy: Data cache writealloc
> > > > [    0.000000] cma: Reserved 16 MiB at 0x00000000fe000000
> > > > [    0.000000] OMAP4: Map 0x000000027fd00000 to fe600000 for
> > > > dram
> > > > barrier
> > > > [    0.000000] On node 0 totalpages: 1043712
> > > > [    0.000000] free_area_init_node: node 0, pgdat c108c240,
> > > > node_mem_map ebff7000
> > > > [    0.000000]   DMA zone: 1536 pages used for memmap
> > > > [    0.000000]   DMA zone: 0 pages reserved
> > > > [    0.000000]   DMA zone: 196608 pages, LIFO batch:31
> > > > [    0.000000]   HighMem zone: 847104 pages, LIFO batch:31
> > > > [    0.000000] OMAP5432 ES2.0
> > > > [    0.000000] percpu: Embedded 17 pages/cpu @ebf8f000 s40704
> > > > r8192
> > > > d20736 u69632
> > > > [    0.000000] pcpu-alloc: s40704 r8192 d20736 u69632
> > > > alloc=17*4096
> > > > [    0.000000] pcpu-alloc: [0] 0 [0] 1 
> > > > [    0.000000] Built 1 zonelists in Zone order, mobility
> > > > grouping
> > > > on.  Total pages: 1042176
> > > > [    0.000000] Kernel command line: console=
> > > > root=PARTUUID=6c9bc324-
> > > > 02 rw rootfstype=ext4 rootwait console=ttyO2,115200n8 vram=12M
> > > > omapfb.vram=0:8M,1:4M omapfb.rotate_type=0 omapdss.def_disp=lcd
> > > > rootwait twl4030_charger.allow_usb=1 musb_hdrc.preserve_vbus=1
> > > > log_buf_len=8M ignore_loglevel earlyprintk
> > > > [    0.000000] log_buf_len: 8388608 bytes
> > > > [    0.000000] early log buf free: 63840(97%)
> > > > [    0.000000] PID hash table entries: 4096 (order: 2, 16384
> > > > bytes)
> > > > [    0.000000] Dentry cache hash table entries: 131072 (order:
> > > > 7,
> > > > 524288 bytes)
> > > > [    0.000000] Inode-cache hash table entries: 65536 (order: 6,
> > > > 262144 bytes)
> > > > [    0.000000] Memory: 4093388K/4174848K available (8192K
> > > > kernel
> > > > code, 586K rwdata, 2240K rodata, 2048K init, 7999K bss, 65076K
> > > > reserved, 16384K cma-reserved, 3372032K highmem)
> > > > [    0.000000] Virtual kernel memory layout:
> > > > [    0.000000]     vector  : 0xffff0000 - 0xffff1000   (   4
> > > > kB)
> > > > [    0.000000]     fixmap  : 0xffc00000 - 0xfff00000   (3072
> > > > kB)
> > > > [    0.000000]     vmalloc : 0xf0800000 - 0xff800000   ( 240
> > > > MB)
> > > > [    0.000000]     lowmem  : 0xc0000000 - 0xf0000000   ( 768
> > > > MB)
> > > > [    0.000000]     pkmap   : 0xbfe00000 - 0xc0000000   (   2
> > > > MB)
> > > > [    0.000000]     modules : 0xbf000000 - 0xbfe00000   (  14
> > > > MB)
> > > > [    0.000000]       .text : 0xc0008000 - 0xc0a00000   (10208
> > > > kB)
> > > > [    0.000000]       .init : 0xc0e00000 - 0xc1000000   (2048
> > > > kB)
> > > > [    0.000000]       .data : 0xc1000000 - 0xc1092900   ( 587
> > > > kB)
> > > > [    0.000000]        .bss : 0xc1092900 - 0xc1862684   (8000
> > > > kB)
> > > > [    0.000000] Running RCU self tests
> > > > [    0.000000] Preemptible hierarchical RCU implementation.
> > > > [    0.000000]  RCU lockdep checking is enabled.
> > > > [    0.000000] NR_IRQS: 16, nr_irqs: 16, preallocated irqs: 16
> > > > [    0.000000] GIC: Using split EOI/Deactivate mode
> > > > [    0.000000] OMAP clockevent source: timer1 at 32768 Hz
> > > > [    0.000000] arch_timer: cp15 timer(s) running at 6.14MHz
> > > > (phys).
> > > > [    0.000000] clocksource: arch_sys_counter: mask:
> > > > 0xffffffffffffff
> > > > max_cycles: 0x16ac02862, max_idle_ns: 440795202218 ns
> > > > [    0.000006] sched_clock: 56 bits at 6MHz, resolution 162ns,
> > > > wraps
> > > > every 4398046511085ns
> > > > [    0.000024] Switching to timer-based delay loop, resolution
> > > > 162ns
> > > > 
> > > > ...
> > > > 
> > > > [    2.220127] Power Management for TI OMAP4+ devices.
> > > > [    2.225399] BUG: using smp_processor_id() in preemptible
> > > > [00000000] code: swapper/0/1
> > > > [    2.233704] caller is pwrdm_set_next_pwrst+0x48/0x1d8
> > > > [    2.239024] CPU: 0 PID: 1 Comm: swapper/0 Not tainted
> > > > 4.13.0-rc2-
> > > > letux-lpae+ #1297
> > > > [    2.246970] Hardware name: Generic OMAP5 (Flattened Device
> > > > Tree)
> > > > [    2.253288] [<c020eaf0>] (unwind_backtrace) from
> > > > [<c020afec>]
> > > > (show_stack+0x10/0x14)
> > > > [    2.261417] [<c020afec>] (show_stack) from [<c084c048>]
> > > > (dump_stack+0x98/0xd0)
> > > > [    2.269000] [<c084c048>] (dump_stack) from [<c055270c>]
> > > > (check_preemption_disabled+0xec/0x124)
> > > > [    2.278042] [<c055270c>] (check_preemption_disabled) from
> > > > [<c022032c>] (pwrdm_set_next_pwrst+0x48/0x1d8)
> > > > [    2.287990] [<c022032c>] (pwrdm_set_next_pwrst) from
> > > > [<c0e0cdd0>]
> > > > (omap4_mpuss_init+0xb4/0x23c)
> > > > [    2.297123] [<c0e0cdd0>] (omap4_mpuss_init) from
> > > > [<c0e0d1ec>]
> > > > (omap4_pm_init+0xf4/0x164)
> > > > [    2.305611] [<c0e0d1ec>] (omap4_pm_init) from [<c0e0a3f4>]
> > > > (omap5_init_late+0x10/0x18)
> > > > [    2.313920] [<c0e0a3f4>] (omap5_init_late) from [<c0e03560>]
> > > > (init_machine_late+0x1c/0x90)
> > > > [    2.322595] [<c0e03560>] (init_machine_late) from
> > > > [<c02018d8>]
> > > > (do_one_initcall+0xa8/0x150)
> > > > [    2.331356] [<c02018d8>] (do_one_initcall) from [<c0e00d94>]
> > > > (kernel_init_freeable+0x110/0x1d4)
> > > > [    2.340482] [<c0e00d94>] (kernel_init_freeable) from
> > > > [<c085d678>]
> > > > (kernel_init+0x8/0x10c)
> > > > [    2.349067] [<c085d678>] (kernel_init) from [<c0206ee8>]
> > > > (ret_from_fork+0x14/0x2c)
> > > > [    2.357093] BUG: using smp_processor_id() in preemptible
> > > > [00000000] code: swapper/0/1
> > > > [    2.357491] ata1: SATA link down (SStatus 0 SControl 300)
> > > > 
> > > > ...
> > > > 
> > > > letux login: root
> > > > Password: 
> > > > Last login: Sat Jan  1 01:38:48 UTC 2000 on console
> > > > Linux letux 4.13.0-rc2-letux-lpae+ #1297 SMP PREEMPT Mon Jul 24
> > > > 13:08:10 CEST 2017 armv7l
> > > > 
> > > > The programs included with the Debian GNU/Linux system are free
> > > > software;
> > > > the exact distribution terms for each program are described in
> > > > the
> > > > individual files in /usr/share/doc/*/copyright.
> > > > 
> > > > Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the
> > > > extent
> > > > permitted by applicable law.
> > > > root at letux:~# cat /proc/meminfo 
> > > > MemTotal:        4111820 kB
> > > > MemFree:         3840616 kB
> > > > MemAvailable:    4022440 kB
> > > > Buffers:            9284 kB
> > > > Cached:           213588 kB
> > > > SwapCached:            0 kB
> > > > Active:           145492 kB
> > > > Inactive:          91496 kB
> > > > Active(anon):      14208 kB
> > > > Inactive(anon):     5392 kB
> > > > Active(file):     131284 kB
> > > > Inactive(file):    86104 kB
> > > > Unevictable:           0 kB
> > > > Mlocked:               0 kB
> > > > HighTotal:       3388416 kB
> > > > HighFree:        3156312 kB
> > > > LowTotal:         723404 kB
> > > > LowFree:          684304 kB
> > > > SwapTotal:             0 kB
> > > > SwapFree:              0 kB
> > > > Dirty:                32 kB
> > > > Writeback:             0 kB
> > > > AnonPages:         14056 kB
> > > > Mapped:             8260 kB
> > > > Shmem:              5488 kB
> > > > Slab:                 32 kB
> > > > SReclaimable:          0 kB
> > > > SUnreclaim:           32 kB
> > > > KernelStack:         720 kB
> > > > PageTables:          280 kB
> > > > NFS_Unstable:          0 kB
> > > > Bounce:                0 kB
> > > > WritebackTmp:          0 kB
> > > > CommitLimit:     2055908 kB
> > > > Committed_AS:      47460 kB
> > > > VmallocTotal:     245760 kB
> > > > VmallocUsed:           0 kB
> > > > VmallocChunk:          0 kB
> > > > CmaTotal:          16384 kB
> > > > CmaFree:           13704 kB
> > > > root at letux:~# memtester 3000m
> > > > memtester version 4.3.0 (32-bit)
> > > > Copyright (C) 2001-2012 Charles Cazabon.
> > > > Licensed under the GNU General Public License version 2 (only).
> > > > 
> > > > pagesize is 4096
> > > > pagesizemask is 0xfffff000
> > > > want 3000MB (3145728000 bytes)
> > > > got  2924MB (3067002880 bytes), trying mlock ...locked.
> > > > Loop 1:
> > > > Stuck Address       : ok         
> > > > Random Value        : ok
> > > > Compare XOR         : ok
> > > > Compare SUB         : ok
> > > > Compare MUL         : ok
> > > > Compare DIV         : ok
> > > > Compare OR          : ok
> > > > Compare AND         : ok
> > > > Sequential Increment: ok
> > > > Solid Bits          : ok         
> > > > Block Sequential    : ok         
> > > > Checkerboard        : ok         
> > > > Bit Spread          : ok         
> > > > Bit Flip            : ok         
> > > > Walking Ones        : ok         
> > > > Walking Zeroes      : ok         
> > > > 8-bit Writes        : ok
> > > > 16-bit Writes       : ok
> > > > 
> > > > Loop 2:
> > > > Stuck Address       : setting  14^C
> > > > root at letux:~# 
> > > > _______________________________________________
> > > > Kernel mailing list
> > > > Kernel at pyra-handheld.com
> > > > http://pyra-handheld.com/cgi-bin/mailman/listinfo/kernel
> > > 
> > > -- 
> > > Mit freundlichen Grüßen,
> > > 
> > > Michael Mrozek
> > > 
> > > -----------------------
> > > OpenPandora GmbH
> > > Geschäftsführer: Michael Mrozek
> > > 
> > > Schäffbräustr. 11
> > > 85049 Ingolstadt
> > > Deutschland
> > > Tel.: 0841 / 990 5548
> > > http://www.openpandora.de/
> > > HRB 4879, Amtsgericht Ingolstadt
> > > -----------------------
> > > eMail: mrozek at openpandora.org
> > 
> > _______________________________________________
> > http://projects.goldelico.com/p/gta04-kernel/
> > Letux-kernel mailing list
> > Letux-kernel at openphoenux.org
> > http://lists.goldelico.com/mailman/listinfo.cgi/letux-kernel
> 
> 
-- 
Mit freundlichen Grüßen,

Michael Mrozek

-----------------------
OpenPandora GmbH
Geschäftsführer: Michael Mrozek

Schäffbräustr. 11
85049 Ingolstadt
Deutschland
Tel.: 0841 / 990 5548
http://www.openpandora.de/
HRB 4879, Amtsgericht Ingolstadt
-----------------------
eMail: mrozek at openpandora.org


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