From 8cf4e6a04f734e831c2ac7f405071d1cde690ba8 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Sat, 3 Feb 2018 11:25:20 +0100 Subject: [PATCH] firmware: dmi: Optimize dmi_matches Function dmi_matches can me made a bit faster: * The documented purpose of dmi_initialized is to catch too early calls to dmi_check_system(). I'm not fully convinced it justifies slowing down the initialization of all systems out there, but at least the check should not have been moved from dmi_check_system() to dmi_matches(). dmi_matches() is being called for every entry of the table passed to dmi_check_system(), causing the same redundant check to be performed again and again. So move it back to dmi_check_system(), reverting this specific portion of commit d7b1956fed33 ("DMI: Introduce dmi_first_match to make the interface more flexible"). * Don't check for the exact_match flag again when we already know its value. Signed-off-by: Jean Delvare Fixes: d7b1956fed33 ("DMI: Introduce dmi_first_match to make the interface more flexible") Cc: Jani Nikula Cc: Daniel Vetter Cc: Rafael J. Wysocki Cc: Jeff Garzik --- drivers/firmware/dmi_scan.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index 783041964439..84356d86f359 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -784,19 +784,20 @@ static bool dmi_matches(const struct dmi_system_id *dmi) { int i; - WARN(!dmi_initialized, KERN_ERR "dmi check: not initialized yet.\n"); - for (i = 0; i < ARRAY_SIZE(dmi->matches); i++) { int s = dmi->matches[i].slot; if (s == DMI_NONE) break; if (dmi_ident[s]) { - if (!dmi->matches[i].exact_match && - strstr(dmi_ident[s], dmi->matches[i].substr)) - continue; - else if (dmi->matches[i].exact_match && - !strcmp(dmi_ident[s], dmi->matches[i].substr)) - continue; + if (dmi->matches[i].exact_match) { + if (!strcmp(dmi_ident[s], + dmi->matches[i].substr)) + continue; + } else { + if (strstr(dmi_ident[s], + dmi->matches[i].substr)) + continue; + } } /* No match */ @@ -832,6 +833,8 @@ int dmi_check_system(const struct dmi_system_id *list) int count = 0; const struct dmi_system_id *d; + WARN(!dmi_initialized, KERN_ERR "dmi check: not initialized yet.\n"); + for (d = list; !dmi_is_end_of_table(d); d++) if (dmi_matches(d)) { count++;