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authorJohnny Lin <johnny_lin@wiwynn.com>2020-12-18 16:47:57 +0800
committerHung-Te Lin <hungte@chromium.org>2020-12-24 08:15:43 +0000
commit749a78d1794661cfbd72121484eb2b9b80361af8 (patch)
treea7ab3f74b903775bf5170cfa6b77279609bc5b7e /src
parenta858ec86e45fe658086cf6abf55066ca1b8d4c40 (diff)
soc/intel/xeon_sp/cpx: Disable isoch operation for performance
Isochronous operation negatively impacts memory performance, as per Intel MLC (Memory Latency Checker) benchmark results. Thus, disable isochronous operation, like analogous UEFI firmware does. The MLC results after disabling isoch: "--max_bandwidth" ALL Reads : 106948.17 3:1 Reads-Writes : 101580.46 2:1 Reads-Writes : 100523.26 1:1 Reads-Writes : 99059.44 Stream-triad like : 97762.47 "--peak_injection_bandwidth" ALL Reads : 105724.3 3:1 Reads-Writes : 100655.8 2:1 Reads-Writes : 99463 1:1 Reads-Writes : 98708 Stream-triad like : 91515 The MLC results before disabling isoch: "--max_bandwidth" ALL Reads : 88824.96 3:1 Reads-Writes : 94820.81 2:1 Reads-Writes : 94867.53 1:1 Reads-Writes : 92567.36 Stream-triad like : 91900.43 "--peak_injection_bandwidth" ALL Reads : 88859.6 3:1 Reads-Writes : 94064 2:1 Reads-Writes : 94186.2 1:1 Reads-Writes : 92516.1 Stream-triad like : 85147.4 TEST=On OCP Delta Lake, verify that MLC benchmark results have improved. Change-Id: I08c22ee001b601e607452b3f23fad969ecb484b4 Signed-off-by: Johnny Lin <johnny_lin@wiwynn.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/48738 Reviewed-by: Marc Jones <marc@marcjonesconsulting.com> Reviewed-by: Jonathan Zhang <jonzhang@fb.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Diffstat (limited to 'src')
-rw-r--r--src/soc/intel/xeon_sp/cpx/romstage.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/src/soc/intel/xeon_sp/cpx/romstage.c b/src/soc/intel/xeon_sp/cpx/romstage.c
index 6f47a30234..e423d0a6d1 100644
--- a/src/soc/intel/xeon_sp/cpx/romstage.c
+++ b/src/soc/intel/xeon_sp/cpx/romstage.c
@@ -163,5 +163,8 @@ void platform_fsp_memory_init_params_cb(FSPM_UPD *mupd, uint32_t version)
m_cfg->VtdSupport = config->vtd_support;
m_cfg->X2apic = config->x2apic;
+ /* Disable ISOC */
+ m_cfg->isocEn = 0;
+
mainboard_memory_init_params(mupd);
}