2019-09-08 13:01:04

by Anatoly Pugachev

Subject: [sparc64] Kernel unaligned access at TPC lzo1x_1_do_compress

Hello!

trying to use zram block device, shows the following:

# zramctl -f -s 16g
# cat /sys/block/zram0/comp_algorithm
lzo [lzo-rle] lz4 lz4hc 842 zstd
# zramctl
NAME ALGORITHM DISKSIZE DATA COMPR TOTAL STREAMS MOUNTPOINT
/dev/zram0 lzo-rle 16G 10.4M 4K 112K 32

# mkfs.xfs /dev/zram0
...

[ 71.095998] zram: Added device: zram0
[ 71.765591] zram0: detected capacity change from 0 to 17179869184
[ 80.058772] Kernel unaligned access at TPC[8f2534]
lzo1x_1_do_compress+0x1b4/0x820
[ 80.073832] Kernel unaligned access at TPC[8f2534]
lzo1x_1_do_compress+0x1b4/0x820
[ 80.073866] Kernel unaligned access at TPC[8f2534]
lzo1x_1_do_compress+0x1b4/0x820
[ 80.074709] Kernel unaligned access at TPC[8f2534]
lzo1x_1_do_compress+0x1b4/0x820
[ 80.074923] Kernel unaligned access at TPC[8f2534]
lzo1x_1_do_compress+0x1b4/0x820


all other tested compression algorithms (lzo, lz4, lz4hc, deflate,
842) work without producing kernel TPC.

2019-09-10 05:14:50

by Dave Rodgman

Subject: Re: [sparc64] Kernel unaligned access at TPC lzo1x_1_do_compress

Thanks Anatoly, I'll take a look at this. Could you please let me know the exact hardware you're running on?

thanks

Dave

________________________________________
From: [email protected] <[email protected]> on behalf of Anatoly Pugachev <[email protected]>
Sent: 08 September 2019 11:58:08
To: Sparc kernel list
Cc: Linux Kernel list
Subject: [sparc64] Kernel unaligned access at TPC lzo1x_1_do_compress

Hello!

trying to use zram block device, shows the following:

# zramctl -f -s 16g
# cat /sys/block/zram0/comp_algorithm
lzo [lzo-rle] lz4 lz4hc 842 zstd
# zramctl
NAME ALGORITHM DISKSIZE DATA COMPR TOTAL STREAMS MOUNTPOINT
/dev/zram0 lzo-rle 16G 10.4M 4K 112K 32

# mkfs.xfs /dev/zram0
...

[ 71.095998] zram: Added device: zram0
[ 71.765591] zram0: detected capacity change from 0 to 17179869184
[ 80.058772] Kernel unaligned access at TPC[8f2534]
lzo1x_1_do_compress+0x1b4/0x820
[ 80.073832] Kernel unaligned access at TPC[8f2534]
lzo1x_1_do_compress+0x1b4/0x820
[ 80.073866] Kernel unaligned access at TPC[8f2534]
lzo1x_1_do_compress+0x1b4/0x820
[ 80.074709] Kernel unaligned access at TPC[8f2534]
lzo1x_1_do_compress+0x1b4/0x820
[ 80.074923] Kernel unaligned access at TPC[8f2534]
lzo1x_1_do_compress+0x1b4/0x820


all other tested compression algorithms (lzo, lz4, lz4hc, deflate,
842) work without producing kernel TPC.
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

2019-09-10 20:10:27

by Anatoly Pugachev

Subject: Re: [sparc64] Kernel unaligned access at TPC lzo1x_1_do_compress

On Mon, Sep 9, 2019 at 1:11 PM Dave Rodgman <[email protected]> wrote:
>
> Thanks Anatoly, I'll take a look at this. Could you please let me know the exact hardware you're running on?

Dave,

machine is a LDOM on T5-2 server.

OS is debian unstable/sid linux with latest git kernel, currently :

$ uname -a
Linux ttip 5.3.0-rc8-dirty #1211 SMP Mon Sep 9 10:20:40 MSK 2019
sparc64 GNU/Linux

-dirty cause non-mainline (yet) fix for IPC [1] and reverted
HAVE_GENERIC_GUP patch [2].

$ gcc --version
gcc (Debian 9.2.1-7) 9.2.1 20190905

$ ld -V
GNU ld (GNU Binutils for Debian) 2.32.51.20190821

$ ldd --version
ldd (Debian GLIBC 2.28-10) 2.28


I could give you account on this box to test or fix kernel if you would like.

Thanks.

1. https://marc.info/?l=linux-kernel&m=156769723218727
2. https://marc.info/?l=linux-sparc&m=156026414826151