s390/zcore: remove /sys/kernel/debug/zcore/mem

New versions of the SCSI dumper use the /dev/vmcore interface instead
of zcore mem. Remove the outdated interface.

Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky
2015-10-28 09:47:58 +01:00
parent bbfed511c2
commit ffa52d02c5
4 changed files with 17 additions and 402 deletions

View File

@@ -15,19 +15,15 @@ the s390-tools package) to make the device bootable. The operator of a Linux
system can then trigger a SCSI dump by booting the SCSI disk, where zfcpdump
resides on.
The kernel part of zfcpdump is implemented as a debugfs file under "zcore/mem",
which exports memory and registers of the crashed Linux in an s390
standalone dump format. It can be used in the same way as e.g. /dev/mem. The
dump format defines a 4K header followed by plain uncompressed memory. The
register sets are stored in the prefix pages of the respective CPUs. To build a
dump enabled kernel with the zcore driver, the kernel config option
CONFIG_CRASH_DUMP has to be set. When reading from "zcore/mem", the part of
memory, which has been saved by hardware is read by the driver via the SCLP
hardware interface. The second part is just copied from the non overwritten real
memory.
The user space dump tool accesses the memory of the crashed system by means
of the /proc/vmcore interface. This interface exports the crashed system's
memory and registers in ELF core dump format. To access the memory which has
been saved by the hardware SCLP requests will be created at the time the data
is needed by /proc/vmcore. The tail part of the crashed systems memory which
has not been stashed by hardware can just be copied from real memory.
Since kernel version 3.12 also the /proc/vmcore file can also be used to access
the dump.
To build a dump enabled kernel the kernel config option CONFIG_CRASH_DUMP
has to be set.
To get a valid zfcpdump kernel configuration use "make zfcpdump_defconfig".