From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 7844) id 7C8083858415; Tue, 12 Sep 2023 03:48:30 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 7C8083858415 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1694490510; bh=th6k3ax/I48XnKZ9rPQeOm6GKFuRWRDOlhi9cKdHuIg=; h=From:To:Subject:Date:From; b=IaKEljNWAEpcxP+nu3t9sF/bmUYcJySfueezzOYMR0WJUA/XmCX9c4rSCd/4rhsoi VDXByNpBgZqjNgyTrjgSyKMzfnYJHA/KMNNvTRYvET/Zgt2fPu/d9C3Qiozz474lcE 1Gm1AYPjcJCRe+vr1R/Lz1+S9tdEewsDGINNnuCM= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Noah Goldstein To: glibc-cvs@sourceware.org Subject: [glibc/release/2.30/master] x86: Fix slight bug in `shared_per_thread` cache size calculation. X-Act-Checkin: glibc X-Git-Author: Noah Goldstein X-Git-Refname: refs/heads/release/2.30/master X-Git-Oldrev: e8132392cd5733e269c2e8c9026716c95bc2b247 X-Git-Newrev: 863fc577db623c4d14a889d38c5f73e2d61dc8e5 Message-Id: <20230912034830.7C8083858415@sourceware.org> Date: Tue, 12 Sep 2023 03:48:30 +0000 (GMT) List-Id: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=863fc577db623c4d14a889d38c5f73e2d61dc8e5 commit 863fc577db623c4d14a889d38c5f73e2d61dc8e5 Author: Noah Goldstein Date: Fri Aug 11 18:48:18 2023 -0500 x86: Fix slight bug in `shared_per_thread` cache size calculation. After: ``` commit af992e7abdc9049714da76cae1e5e18bc4838fb8 Author: Noah Goldstein Date: Wed Jun 7 13:18:01 2023 -0500 x86: Increase `non_temporal_threshold` to roughly `sizeof_L3 / 4` ``` Split `shared` (cumulative cache size) from `shared_per_thread` (cache size per socket), the `shared_per_thread` *can* be slightly off from the previous calculation. Previously we added `core` even if `threads_l2` was invalid, and only used `threads_l2` to divide `core` if it was present. The changed version only included `core` if `threads_l2` was valid. This change restores the old behavior if `threads_l2` is invalid by adding the entire value of `core`. Reviewed-by: DJ Delorie (cherry picked from commit 47f747217811db35854ea06741be3685e8bbd44d) Diff: --- sysdeps/x86/cacheinfo.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/sysdeps/x86/cacheinfo.c b/sysdeps/x86/cacheinfo.c index ac98741ac6..62986a7327 100644 --- a/sysdeps/x86/cacheinfo.c +++ b/sysdeps/x86/cacheinfo.c @@ -696,8 +696,8 @@ init_cacheinfo (void) /* Account for non-inclusive L2 and L3 caches. */ if (!inclusive_cache) { - if (threads_l2 > 0) - shared_per_thread += core / threads_l2; + long int core_per_thread = threads_l2 > 0 ? (core / threads_l2) : core; + shared_per_thread += core_per_thread; shared += core; } }