This changes the way we calculate how much space to reserve for the
pHyp dump. Currently we reserve 256MB only. With this change, the
code first checks to see if an amount has been specified on the boot
command line with the "phyp_dump_reserve_size" option, and if so, uses
that much.
Otherwise it computes 5% of total ram and rounds it down to a multiple
of 256MB, and uses the larger of that or 256MB.
This is for large systems with a lot of memory (10GB or more). The
aim is to have more space available for the kernel on reboot on
machines with more resources. Although the dump will be collected
pretty fast and the memory released really early on allowing the
machine to have the full memory available, this alleviates any issues
that can be caused by having way too little memory on very very large
systems during those few minutes.
Signed-off-by: Manish Ahuja <mahuja@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This adds a kernel command line option "phyp_dump", which takes a 0/1
value for disabling/ enabling phyp_dump at boot time. Kdump can use
this on cmdline (phyp_dump=0) to disable phyp-dump during boot when
enabling itself. This will ensure only one dumping mechanism is active
at any given time.
Signed-off-by: Manish Ahuja <mahuja@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This adds routines to
a. invalidate dump
b. calculate region that is reserved and needs to be freed. This is
exported through sysfs interface.
Unregister has been removed for now as it wasn't being used.
Signed-off-by: Manish Ahuja <mahuja@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Initial patch for reserving memory in early boot, and freeing it
later. If the previous boot had ended with a crash, the reserved
memory would contain a copy of the crashed kernel data.
Signed-off-by: Manish Ahuja <mahuja@us.ibm.com>
Signed-off-by: Linas Vepstas <linasvepstas@gmail.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
