linux_dsm_epyc7002/arch
bob picco 7c21d533ab sparc64: mem boot option correction
The "mem" boot option can result in many unexpected consequences. This patch
attempts to prevent boot hangs which have been experienced on T4-4 and T5-8.
Basically the boot loader allocates vmlinuz and initrd higher in available
OBP physical memory. For example, on a 2Tb T5-8 it isn't possible to boot
with mem=20G.

The patch utilizes memblock to avoid reserved regions and trim memory which
is only free. Other improvements are possible for a multi-node machine.

This is a snippet of the boot log with mem=20G on T5-8 with the patch applied:
MEMBLOCK configuration:	<- before memory reduction
 memory size = 0x1ffad6ce000 reserved size = 0xa1adf44
 memory.cnt  = 0xb
 memory[0x0]    [0x00000030400000-0x00003fdde47fff], 0x3fada48000 bytes
 memory[0x1]    [0x00003fdde4e000-0x00003fdde4ffff], 0x2000 bytes
 memory[0x2]    [0x00080000000000-0x00083fffffffff], 0x4000000000 bytes
 memory[0x3]    [0x00100000000000-0x00103fffffffff], 0x4000000000 bytes
 memory[0x4]    [0x00180000000000-0x00183fffffffff], 0x4000000000 bytes
 memory[0x5]    [0x00200000000000-0x00203fffffffff], 0x4000000000 bytes
 memory[0x6]    [0x00280000000000-0x00283fffffffff], 0x4000000000 bytes
 memory[0x7]    [0x00300000000000-0x00303fffffffff], 0x4000000000 bytes
 memory[0x8]    [0x00380000000000-0x00383fffc71fff], 0x3fffc72000 bytes
 memory[0x9]    [0x00383fffc92000-0x00383fffca1fff], 0x10000 bytes
 memory[0xa]    [0x00383fffcb4000-0x00383fffcb5fff], 0x2000 bytes
 reserved.cnt  = 0x2
 reserved[0x0]  [0x00380000000000-0x0038000117e7f8], 0x117e7f9 bytes
 reserved[0x1]  [0x00380004000000-0x0038000d02f74a], 0x902f74b bytes
...
MEMBLOCK configuration:	<- after reduction of memory
 memory size = 0x50a1adf44 reserved size = 0xa1adf44
 memory.cnt  = 0x4
 memory[0x0]    [0x00380000000000-0x0038000117e7f8], 0x117e7f9 bytes
 memory[0x1]    [0x00380004000000-0x0038050d01d74a], 0x50901d74b bytes
 memory[0x2]    [0x00383fffc92000-0x00383fffca1fff], 0x10000 bytes
 memory[0x3]    [0x00383fffcb4000-0x00383fffcb5fff], 0x2000 bytes
 reserved.cnt  = 0x2
 reserved[0x0]  [0x00380000000000-0x0038000117e7f8], 0x117e7f9 bytes
 reserved[0x1]  [0x00380004000000-0x0038000d02f74a], 0x902f74b bytes
...
Early memory node ranges
  node   7: [mem 0x380000000000-0x38000117dfff]
  node   7: [mem 0x380004000000-0x380f0d01bfff]
  node   7: [mem 0x383fffc92000-0x383fffca1fff]
  node   7: [mem 0x383fffcb4000-0x383fffcb5fff]
Could not find start_pfn for node 0
Could not find start_pfn for node 1
Could not find start_pfn for node 2
Could not find start_pfn for node 3
Could not find start_pfn for node 4
Could not find start_pfn for node 5
Could not find start_pfn for node 6
.

The patch was tested on T4-1, T5-8 and Jalap?no.

Cc: sparclinux@vger.kernel.org
Signed-off-by: Bob Picco <bob.picco@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-16 18:23:11 -07:00
..
alpha alpha: io: implement relaxed accessor macros for writes 2014-08-29 11:18:45 -07:00
arc ARC: [mm] Fix compilation breakage 2014-09-03 10:08:50 -07:00
arm A smattering of bug fixes across most architectures. 2014-09-06 16:42:12 -07:00
arm64 A smattering of bug fixes across most architectures. 2014-09-06 16:42:12 -07:00
avr32 Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
blackfin Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
c6x Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
cris Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
frv frv: Define cpu_relax_lowlatency() 2014-08-19 09:40:08 -05:00
hexagon flush_icache_range: export symbol to fix build errors 2014-08-29 16:28:17 -07:00
ia64 kexec: remove CONFIG_KEXEC dependency on crypto 2014-08-29 16:28:16 -07:00
m32r Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
m68k m68k: Wire up memfd_create 2014-09-01 10:28:00 +02:00
metag Metag architecture changes for v3.17 2014-08-13 18:18:09 -06:00
microblaze microblaze: Fix number of syscalls 2014-09-09 13:14:47 +02:00
mips kexec: remove CONFIG_KEXEC dependency on crypto 2014-08-29 16:28:16 -07:00
mn10300 Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
openrisc Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
parisc Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
powerpc A smattering of bug fixes across most architectures. 2014-09-06 16:42:12 -07:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2014-09-08 08:27:00 -07:00
score Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
sh flush_icache_range: export symbol to fix build errors 2014-08-29 16:28:17 -07:00
sparc sparc64: mem boot option correction 2014-09-16 18:23:11 -07:00
tile flush_icache_range: export symbol to fix build errors 2014-08-29 16:28:17 -07:00
um Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2014-08-09 09:58:12 -07:00
unicore32 unicore32: Fix build error 2014-08-31 17:08:12 -07:00
x86 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-08-29 17:22:27 -07:00
xtensa Xtensa improvements for 3.17: 2014-08-31 17:08:42 -07:00
.gitignore
Kconfig seccomp: add "seccomp" syscall 2014-07-18 12:13:37 -07:00