From 938179b4f8cf8a4f11234ebf2dff2eb48400acfe Mon Sep 17 00:00:00 2001 From: Dimitri Sivanich <sivanich@sgi.com> Date: Fri, 5 Mar 2010 11:42:03 -0600 Subject: x86: Improve Intel microcode loader performance 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> --- arch/x86/kernel/microcode_intel.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/microcode_intel.c b/arch/x86/kernel/microcode_intel.c index 85a343e2893..356170262a9 100644 --- a/arch/x86/kernel/microcode_intel.c +++ b/arch/x86/kernel/microcode_intel.c @@ -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); -- cgit v1.2.2