From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f65.google.com ([209.85.215.65]:38689 "EHLO mail-lf0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751116AbeEDAP5 (ORCPT ); Thu, 3 May 2018 20:15:57 -0400 From: Timofey Titovets To: linux-raid@vger.kernel.org Cc: Timofey Titovets , linux-btrfs@vger.kernel.org Subject: [RFC PATCH] raid6_pq: Add module options to prefer algorithm Date: Fri, 4 May 2018 03:15:41 +0300 Message-Id: <20180504001541.2068-1-nefelim4ag@gmail.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: Skip testing unnecessary algorithms to speedup module initialization For my systems: Before: 1.510s (initrd) After: 977ms (initrd) # I set prefer to fastest algorithm Dmesg after patch: [ 1.190042] raid6: avx2x4 gen() 28153 MB/s [ 1.246683] raid6: avx2x4 xor() 19440 MB/s [ 1.246684] raid6: using algorithm avx2x4 gen() 28153 MB/s [ 1.246684] raid6: .... xor() 19440 MB/s, rmw enabled [ 1.246685] raid6: using avx2x2 recovery algorithm Signed-off-by: Timofey Titovets CC: linux-btrfs@vger.kernel.org --- lib/raid6/algos.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/lib/raid6/algos.c b/lib/raid6/algos.c index 5065b1e7e327..abfcb4107fc3 100644 --- a/lib/raid6/algos.c +++ b/lib/raid6/algos.c @@ -30,6 +30,11 @@ EXPORT_SYMBOL(raid6_empty_zero_page); #endif #endif +static char *prefer_name; + +module_param(prefer_name, charp, 0); +MODULE_PARM_DESC(prefer_name, "Prefer gen/xor() algorithm"); + struct raid6_calls raid6_call; EXPORT_SYMBOL_GPL(raid6_call); @@ -155,10 +160,27 @@ static inline const struct raid6_calls *raid6_choose_gen( { unsigned long perf, bestgenperf, bestxorperf, j0, j1; int start = (disks>>1)-1, stop = disks-3; /* work on the second half of the disks */ - const struct raid6_calls *const *algo; - const struct raid6_calls *best; + const struct raid6_calls *const *algo = NULL; + const struct raid6_calls *best = NULL; + + if (strlen(prefer_name)) { + for (algo = raid6_algos; strlen(prefer_name) && *algo; algo++) { + if (!strncmp(prefer_name, (*algo)->name, 8)) { + best = *algo; + break; + } + } + if (!best) + pr_info("raid6: %-8s prefer not found\n", prefer_name); + } + + + + if (!algo) { + algo = raid6_algos; + } - for (bestgenperf = 0, bestxorperf = 0, best = NULL, algo = raid6_algos; *algo; algo++) { + for (bestgenperf = 0, bestxorperf = 0; *algo; algo++) { if (!best || (*algo)->prefer >= best->prefer) { if ((*algo)->valid && !(*algo)->valid()) continue; -- 2.17.0