Jens found the following crash/regression:
[ 0.000000] found SMP MP-table at [ffff8800000fdd80] fdd80
[ 0.000000] Kernel panic - not syncing: Overlapping early reservations 12-f011 MP-table mpc to 0-fff BIOS data page
and
[ 0.000000] Kernel panic - not syncing: Overlapping early reservations 12-f011 MP-table mpc to 6000-7fff TRAMPOLINE
and bisected it to b24c2a9 ("x86: Move find_smp_config()
earlier and avoid bootmem usage").
It turns out the BIOS is using the first 64k for mptable,
without reserving it.
So try to find good range for the real-mode trampoline instead of
hard coding it, in case some bios tries to use that range for sth.
Reported-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Tested-by: Jens Axboe <jens.axboe@oracle.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
LKML-Reference: <4B21630A.6000308@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix trampoline sizing bug, save space
While debugging a suspend-to-RAM related issue it occured to me that
if the trampoline code had grown past 4 KB, we would have been
allocating too little memory for it, since the 4 KB size of the
trampoline is hardcoded into arch/x86/kernel/e820.c . Change that
by making the kernel compute the trampoline size and allocate as much
memory as necessary.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
