system/linux
system/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux synced 2024-09-24 05:17:36 +00:00
Code Issues Packages Projects Releases Wiki Activity

x86: Improve Intel microcode loader performance

Browse source 
We've noticed that on large SGI UV system configurations,
running microcode.ctl can take very long periods of time.  This
is due to the large number of vmalloc/vfree calls made by the
Intel generic_load_microcode() logic.

By reusing allocated space, the following patch reduces the time
to run microcode.ctl on a 1024 cpu system from approximately 80
seconds down to 1 or 2 seconds.

Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Acked-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Bill Davidsen <davidsen@tmr.com>
LKML-Reference: <20100305174203.GA19638@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Dimitri Sivanich 2010-03-05 11:42:03 -06:00 committed by Ingo Molnar
parent 522dba7134
commit 938179b4f8
1 changed files with 16 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

22
arch/x86/kernel/microcode_intel.c
View file

@ -343,10 +343,11 @@ static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
int (*get_ucode_data)(void *, const void *, size_t))
{
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
u8 *ucode_ptr = data, *new_mc = NULL, *mc;
u8 *ucode_ptr = data, *new_mc = NULL, *mc = NULL;
int new_rev = uci->cpu_sig.rev;
unsigned int leftover = size;
enum ucode_state state = UCODE_OK;
unsigned int curr_mc_size = 0;
while (leftover) {
struct microcode_header_intel mc_header;
@ -361,9 +362,15 @@ static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
break;
}
mc = vmalloc(mc_size);
if (!mc)
break;
/* For performance reasons, reuse mc area when possible */
if (!mc || mc_size > curr_mc_size) {
if (mc)
vfree(mc);
mc = vmalloc(mc_size);
if (!mc)
break;
curr_mc_size = mc_size;
}
if (get_ucode_data(mc, ucode_ptr, mc_size) ||
microcode_sanity_check(mc) < 0) {
@ -376,13 +383,16 @@ static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
vfree(new_mc);
new_rev = mc_header.rev;
new_mc = mc;
} else
vfree(mc);
mc = NULL; /* trigger new vmalloc */
}
ucode_ptr += mc_size;
leftover -= mc_size;
}
if (mc)
vfree(mc);
if (leftover) {
if (new_mc)
vfree(new_mc);