diff options
| author | Andres Salomon <dilinger@queued.net> | 2010-11-29 23:39:51 +0000 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2010-12-15 17:11:40 -0800 |
| commit | b5318d302f8a20eacbbfc01b0ee35b108085a363 (patch) | |
| tree | d16b882c326cbe95fde6f3fb46b5e5b2b1b93d49 /arch/x86/kernel/irq.c | |
| parent | c10d1e260f7cb6766dc76b4e36ed8f4be53f195a (diff) | |
x86, olpc: Speed up device tree creation during boot
Calling alloc_bootmem() for tiny chunks of memory over and over is really
slow; on an XO-1, it caused the time between when the kernel started
booting and when the display came alive (post-lxfb probe) to increase
to 44s. This patch optimizes the prom_early_alloc function by
calling alloc_bootmem for 4k-sized blocks of memory, and handing out
chunks of that to callers. With this patch, the time between kernel load
and display initialization decreased to 23s. If there's a better way to
do this early in the boot process, please let me know.
(Note: increasing the chunk size to 16k didn't noticably affect boot time,
and wasted 9k.)
v4: clarify comment, requested by hpa
v3: fix wasted memory buglet found by Milton Miller, and style fix.
v2: reorder prom_early_alloc as suggested by Grant.
Signed-off-by: Andres Salomon <dilinger@queued.net>
LKML-Reference: <20101129153951.74202a84@queued.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/kernel/irq.c')
0 files changed, 0 insertions, 0 deletions