From nobody Mon Aug 29 16:13:52 2022 X-Original-To: dev-commits-src-main@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4MGb8x029xz4bQdj; Mon, 29 Aug 2022 16:13:53 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4MGb8w6cdkz3F29; Mon, 29 Aug 2022 16:13:52 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1661789632; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=EZWAsP7Yc92sgF4rONib+jCWteEdv9HHRzAJA07RDys=; b=UgB6J8+RjRaKT+QfrEtHb3XhdT3d428aZBIV0sUeFdKdbV2xEb75YZmg8pugoBxXB59kkj DzBNQ3PhiPP5hl4xHosgcrbEmqRThuuUCsHaTNfhH2RNdozjm6UPCOvEPgy90mmS95Z0Oa Xhzn9q1regRLF760oJMW3MjgZ21hKG5p3wJot46nQzPS7lIMzof+Xff2qvZ9cOkydIKaem cBOT7MGFan9tVh2OO0eXGvIX4GXJABzhD5R/e5Buh3WynM7m3rm71kytGydAlBzZMiLCIS CoxxU4z2V6m5BzebRqZR8Cl6ikz8Ubn86WjJqmgViPplNWjbi0b6Z6wWPtW9Jw== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4MGb8w5j5dzTfg; Mon, 29 Aug 2022 16:13:52 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 27TGDqT5050664; Mon, 29 Aug 2022 16:13:52 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 27TGDqSO050663; Mon, 29 Aug 2022 16:13:52 GMT (envelope-from git) Date: Mon, 29 Aug 2022 16:13:52 GMT Message-Id: <202208291613.27TGDqSO050663@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Doug Moore Subject: git: 5d91386826d0 - main - rb_tree: avoid extra reads in rebalancing List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-main@freebsd.org X-BeenThere: dev-commits-src-main@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: dougm X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 5d91386826d0f360d87ce3f39c9ebf266f149325 Auto-Submitted: auto-generated ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1661789632; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=EZWAsP7Yc92sgF4rONib+jCWteEdv9HHRzAJA07RDys=; b=sLEnZGbO8SNJOnzOdkTZpeXGEduWWOkepfykjVKzBFRd9Y+uauHxJogNKYWf4wgCg9nV39 +Om/B2N1n6DTqc7Fvh79RbU2b+a7kxH8fqgKx80mj6uFicVeVE+E6zeOFGyHIFa8YF3nWz ou4X/Mq+/BoKJBG5c4v0n6vCCjuv69zgwn2j5H2e567XQpqaBnpos/QJDm9UxU7eQQ055N MzaLlwGMaOPyECn007VXa3TcBWGFiIU02QXq2mAjgF+1jUiZxGdakUk9RQ/Kp9h8k7hWUf ZaRx2emAH82YrdG7LXqUIMkPANFG9mL0j3zIOU+E0gznOhwlwpOQvn2/WkLW5w== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1661789632; a=rsa-sha256; cv=none; b=G0UJxDEg3s0LQ9MZXKNX3+iiUjgxtzxGKjDmaOquK5JIqZ8TNtd64BLy0hshu+Rs5aen7D MyEPfWtYN/De6fJxpven2EdRqhY9Fg6Y5x1BvZNvZscoSe1UPVK9rB0I+1s342D3heAKpb dzpJ+Tn8tnHCxwZPysq600qTueiGNmj6mrMeqgSESiN0X8V3OHVsxAFkialF/jJ2RTMddJ fcyxhty3+5Cq8B625Fi5d+a7yPbjzFFQobm6VuiAYYwPr8pzhOczbZ2/tA1GTlfqeoyuQi e8tBfjqEnOXr4Nnblqy/BhwlW1rwoCsIa1KZvIp0efUNPtVV5KtULKhjPZxhQw== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-ThisMailContainsUnwantedMimeParts: N The branch main has been updated by dougm: URL: https://cgit.FreeBSD.org/src/commit/?id=5d91386826d0f360d87ce3f39c9ebf266f149325 commit 5d91386826d0f360d87ce3f39c9ebf266f149325 Author: Doug Moore AuthorDate: 2022-08-29 16:11:31 +0000 Commit: Doug Moore CommitDate: 2022-08-29 16:11:31 +0000 rb_tree: avoid extra reads in rebalancing In RB_INSERT_COLOR and RB_REMOVE_COLOR, avoid reading a parent pointer from memory, and then reading the left-color bit from memory, and then reading the right-color bit from memory, since they're all in the same field. The compiler can't infer that only the first read is really necessary, so write the code in a way so that it doesn't have to. Drop RB_RED_LEFT and RB_RED_RIGHT macros that reach into memory to get those bits. Drop RB_COLOR, the only thing left using RB_RED_LEFT and RB_RED_RIGHT after the other changes, and go straight to DIAGNOSTIC code in subr_stats to implement RB_COLOR for its single, dubious use there. Reviewed by: alc MFC after: 3 weeks Differential Revision: https://reviews.freebsd.org/D36353 --- sys/kern/subr_stats.c | 9 +++++- sys/sys/tree.h | 82 +++++++++++++++++++++++++++------------------------ 2 files changed, 52 insertions(+), 39 deletions(-) diff --git a/sys/kern/subr_stats.c b/sys/kern/subr_stats.c index 946999263898..0984d2a21014 100644 --- a/sys/kern/subr_stats.c +++ b/sys/kern/subr_stats.c @@ -3406,6 +3406,13 @@ stats_v1_vsd_tdgst_add(enum vsd_dtype vs_dtype, struct voistatdata_tdgst *tdgst, Q_TOSTR(rbctd64->mu, -1, 10, qstr, sizeof(qstr)); + struct voistatdata_tdgstctd64 *parent; + parent = RB_PARENT(rbctd64, rblnk); + int rb_color = + parent == NULL ? 0 : + RB_LEFT(parent, rblnk) == rbctd64 ? + (RB_BITS(parent, rblnk) & RB_RED_L) != 0 : + (RB_BITS(parent, rblnk) & RB_RED_R) != 0; printf(" RB ctd=%3d p=%3d l=%3d r=%3d c=%2d " "mu=%s\n", (int)ARB_SELFIDX(ctd64tree, rbctd64), @@ -3415,7 +3422,7 @@ stats_v1_vsd_tdgst_add(enum vsd_dtype vs_dtype, struct voistatdata_tdgst *tdgst, RB_LEFT(rbctd64, rblnk)), (int)ARB_SELFIDX(ctd64tree, RB_RIGHT(rbctd64, rblnk)), - RB_COLOR(rbctd64, rblnk), + rb_color, qstr); panic("RB@%p and ARB@%p trees differ\n", diff --git a/sys/sys/tree.h b/sys/sys/tree.h index bd804c1a64db..971562a5c121 100644 --- a/sys/sys/tree.h +++ b/sys/sys/tree.h @@ -341,8 +341,6 @@ struct { \ #define RB_FLIP_LEFT(elm, field) (RB_BITS(elm, field) ^= RB_RED_L) #define RB_FLIP_RIGHT(elm, field) (RB_BITS(elm, field) ^= RB_RED_R) #define RB_FLIP_ALL(elm, field) (RB_BITS(elm, field) ^= RB_RED_MASK) -#define RB_RED_LEFT(elm, field) ((RB_BITS(elm, field) & RB_RED_L) != 0) -#define RB_RED_RIGHT(elm, field) ((RB_BITS(elm, field) & RB_RED_R) != 0) #define _RB_PARENT_ONLY(elm) (__typeof(elm)) \ ((__uintptr_t)elm & ~RB_RED_MASK) #define RB_PARENT(elm, field) _RB_PARENT_ONLY(RB_UP(elm, field)) @@ -359,11 +357,6 @@ struct { \ RB_LEFT(elm, field) = RB_RIGHT(elm, field) = NULL; \ } while (/*CONSTCOND*/ 0) -#define RB_COLOR(elm, field) (RB_PARENT(elm, field) == NULL ? 0 : \ - RB_LEFT(RB_PARENT(elm, field), field) == elm ? \ - RB_RED_LEFT(RB_PARENT(elm, field), field) : \ - RB_RED_RIGHT(RB_PARENT(elm, field), field)) - /* * Something to be invoked in a loop at the root of every modified subtree, * from the bottom up to the root, to update augmented node data. @@ -489,67 +482,72 @@ name##_RB_INSERT_COLOR(struct name *head, struct type *elm) \ * when a value has been assigned to 'child' in the previous \ * one. \ */ \ - struct type *child, *gpar, *parent; \ - while ((parent = RB_PARENT(elm, field)) != NULL) { \ - gpar = RB_PARENT(parent, field); \ + struct type *child, *gpar = RB_UP(elm, field), *parent; \ + __uintptr_t red; \ + \ + while ((parent = gpar) != NULL) { \ + red = RB_BITS(parent, field); \ + gpar = RB_UP(parent, field); \ if (RB_LEFT(parent, field) == elm) { \ - if (RB_RED_LEFT(parent, field)) { \ + if (red & RB_RED_L) { \ RB_FLIP_LEFT(parent, field); \ return; \ } \ RB_FLIP_RIGHT(parent, field); \ - if (RB_RED_RIGHT(parent, field)) { \ + if ((red & RB_RED_MASK) == 0) { \ child = elm; \ elm = parent; \ continue; \ } \ - if (RB_RED_RIGHT(elm, field)) \ + red = RB_BITS(elm, field); \ + if (red & RB_RED_R) \ child = elm; \ else { \ /* coverity[uninit_use] */ \ RB_ROTATE_LEFT(elm, child, field); \ - if (RB_RED_RIGHT(child, field)) \ + red = RB_BITS(child, field); \ + if (red & RB_RED_R) \ RB_FLIP_LEFT(parent, field); \ - if (RB_RED_LEFT(child, field)) \ + if (red & RB_RED_L) \ RB_FLIP_ALL(elm, field); \ else \ RB_FLIP_LEFT(elm, field); \ - if ((RB_BITS(child, field) & \ - RB_RED_MASK) == 0) \ + if ((red & RB_RED_MASK) == 0) \ elm = child; \ } \ RB_ROTATE_RIGHT(parent, child, field); \ } else { \ - if (RB_RED_RIGHT(parent, field)) { \ + if (red & RB_RED_R) { \ RB_FLIP_RIGHT(parent, field); \ return; \ } \ RB_FLIP_LEFT(parent, field); \ - if (RB_RED_LEFT(parent, field)) { \ + if ((red & RB_RED_MASK) == 0) { \ child = elm; \ elm = parent; \ continue; \ } \ - if (RB_RED_LEFT(elm, field)) \ + red = RB_BITS(elm, field); \ + if (red & RB_RED_L) \ child = elm; \ else { \ /* coverity[uninit_use] */ \ RB_ROTATE_RIGHT(elm, child, field); \ - if (RB_RED_LEFT(child, field)) \ + red = RB_BITS(child, field); \ + if (red & RB_RED_L) \ RB_FLIP_RIGHT(parent, field); \ - if (RB_RED_RIGHT(child, field)) \ + if (red & RB_RED_R) \ RB_FLIP_ALL(elm, field); \ else \ RB_FLIP_RIGHT(elm, field); \ - if ((RB_BITS(child, field) & \ - RB_RED_MASK) == 0) \ + if ((red & RB_RED_MASK) == 0) \ elm = child; \ } \ RB_ROTATE_LEFT(parent, child, field); \ } \ - RB_SET_PARENT(child, gpar, field); \ + gpar = _RB_PARENT_ONLY(gpar); \ + RB_UP(child, field) = gpar; \ RB_SWAP_CHILD(head, gpar, parent, child, field); \ - RB_BITS(child, field) &= ~RB_RED_MASK; \ if (elm != child) \ RB_AUGMENT(elm); \ RB_AUGMENT(parent); \ @@ -574,6 +572,8 @@ name##_RB_REMOVE_COLOR(struct name *head, \ struct type *parent, struct type *elm) \ { \ struct type *gpar, *sib; \ + __uintptr_t red; \ + \ if (RB_LEFT(parent, field) == elm && \ RB_RIGHT(parent, field) == elm) { \ RB_BITS(parent, field) &= ~RB_RED_MASK; \ @@ -583,19 +583,21 @@ name##_RB_REMOVE_COLOR(struct name *head, \ return; \ } \ do { \ - gpar = RB_PARENT(parent, field); \ + red = RB_BITS(parent, field); \ + gpar = RB_UP(parent, field); \ if (RB_LEFT(parent, field) == elm) { \ - if (!RB_RED_LEFT(parent, field)) { \ + if (~red & RB_RED_L) { \ RB_FLIP_LEFT(parent, field); \ return; \ } \ - if (RB_RED_RIGHT(parent, field)) { \ + if ((~red & RB_RED_MASK) == 0) { \ RB_FLIP_RIGHT(parent, field); \ elm = parent; \ continue; \ } \ sib = RB_RIGHT(parent, field); \ - switch (RB_BITS(sib, field) & RB_RED_MASK) { \ + red = RB_BITS(sib, field); \ + switch (red & RB_RED_MASK) { \ case RB_RED_MASK: \ RB_FLIP_ALL(sib, field); \ elm = parent; \ @@ -603,11 +605,12 @@ name##_RB_REMOVE_COLOR(struct name *head, \ case RB_RED_R: \ elm = RB_LEFT(sib, field); \ RB_ROTATE_RIGHT(sib, elm, field); \ - if (RB_RED_LEFT(elm, field)) \ + red = RB_BITS(elm, field); \ + if (red & RB_RED_L) \ RB_FLIP_ALL(parent, field); \ else \ RB_FLIP_LEFT(parent, field); \ - if (RB_RED_RIGHT(elm, field)) \ + if (red & RB_RED_R) \ RB_FLIP_ALL(sib, field); \ else \ RB_FLIP_RIGHT(sib, field); \ @@ -629,17 +632,18 @@ name##_RB_REMOVE_COLOR(struct name *head, \ } \ RB_ROTATE_LEFT(parent, elm, field); \ } else { \ - if (!RB_RED_RIGHT(parent, field)) { \ + if (~red & RB_RED_R) { \ RB_FLIP_RIGHT(parent, field); \ return; \ } \ - if (RB_RED_LEFT(parent, field)) { \ + if ((~red & RB_RED_MASK) == 0) { \ RB_FLIP_LEFT(parent, field); \ elm = parent; \ continue; \ } \ sib = RB_LEFT(parent, field); \ - switch (RB_BITS(sib, field) & RB_RED_MASK) { \ + red = RB_BITS(sib, field); \ + switch (red & RB_RED_MASK) { \ case RB_RED_MASK: \ RB_FLIP_ALL(sib, field); \ elm = parent; \ @@ -647,11 +651,12 @@ name##_RB_REMOVE_COLOR(struct name *head, \ case RB_RED_L: \ elm = RB_RIGHT(sib, field); \ RB_ROTATE_LEFT(sib, elm, field); \ - if (RB_RED_RIGHT(elm, field)) \ + red = RB_BITS(elm, field); \ + if (red & RB_RED_R) \ RB_FLIP_ALL(parent, field); \ else \ RB_FLIP_RIGHT(parent, field); \ - if (RB_RED_LEFT(elm, field)) \ + if (red & RB_RED_L) \ RB_FLIP_ALL(sib, field); \ else \ RB_FLIP_LEFT(sib, field); \ @@ -673,12 +678,13 @@ name##_RB_REMOVE_COLOR(struct name *head, \ } \ RB_ROTATE_RIGHT(parent, elm, field); \ } \ + gpar = _RB_PARENT_ONLY(gpar); \ RB_SET_PARENT(elm, gpar, field); \ RB_SWAP_CHILD(head, gpar, parent, elm, field); \ if (sib != elm) \ RB_AUGMENT(sib); \ break; \ - } while ((parent = RB_PARENT(elm, field)) != NULL); \ + } while ((parent = _RB_PARENT_ONLY(gpar)) != NULL); \ } #define RB_GENERATE_REMOVE(name, type, field, attr) \