From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55998C433DF for ; Mon, 3 Aug 2020 22:15:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6472120658 for ; Mon, 3 Aug 2020 22:15:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=posk.io header.i=@posk.io header.b="dUlaLNfU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728490AbgHCWPQ (ORCPT ); Mon, 3 Aug 2020 18:15:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48472 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726130AbgHCWPP (ORCPT ); Mon, 3 Aug 2020 18:15:15 -0400 Received: from mail-oi1-x241.google.com (mail-oi1-x241.google.com [IPv6:2607:f8b0:4864:20::241]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48BCFC06174A for ; Mon, 3 Aug 2020 15:15:15 -0700 (PDT) Received: by mail-oi1-x241.google.com with SMTP id j7so18269073oij.9 for ; Mon, 03 Aug 2020 15:15:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=posk.io; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=68OLwltgUQg9vRu6vY0+7ejuVFhq0Gr6CZjdfuZPmtg=; b=dUlaLNfUn8pSCsrSoGlCqiQOJzeiqHDmFXusW7XCapF3lUoJ94SHcoWA2Ht5NReB07 GWsS54MTXvSpw52wv0U2oLdjc41LlJrAWom/zf8LcTTiY3dH44EDEqySjwCnwnfm23c8 b/cZV0gCY8yR97F3+OcLfKmJd6semh8drm8VAEcuMQeTa2vdWoaaRIbgcKFdXqsjpDYI t7NMyTLIIyc1oJaJ2NXoRqHjSVkCGRq1WJ44f8+9Qk+wfUHk9p51pXA1T9nWmbqdAa+a vu941sh/ofga3/7LCjCJ/PH2SPlsSRdigFheVxmDuZTviDkwZh44cQ0qE3FgTV3qNImg R2mA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=68OLwltgUQg9vRu6vY0+7ejuVFhq0Gr6CZjdfuZPmtg=; b=bAwlIXg0FNdeig9idq4/+llJzYDOnBHM6xs0u0HNyVGFcIe6WT+tQvyAeO6ghiM8TV ZbUPuKZlirRRngHn0Xf29Xa+Eu1OB/tbJJRNYe/gMFLBfQwWZxjPrfLiHXWxOYYFjPNj yqLaC6Iz3MPReOeGM/dKhFUPn8MMFed/Yd14C3EfGyQdRkHHBk9YKcTJTKFXjRbRIoJY gRTHGIpEVkvsTH8w/LgbCtOuSQB+MtUYlCOnlr+o29X2j/FexsAMsNyFYE5id/LkxP8i 2SXZhlWgkmei5a1FQBmavOp58bFvZrnwXIVGKoT6pFrpuGeqw5jiDJSiucQPnMtGYREY DMEA== X-Gm-Message-State: AOAM530WzunbkXd/60FAm83SYcXKQlT1aGhFYvvyL/mYY7ieUNoD9O+M 1TcZulcjyqOZNbycXtRY2wu70yPgikU= X-Google-Smtp-Source: ABdhPJxaFCZHtmnCz6tocBNkOy2cvaG6wwVAISz5l8TnDLYgjwrMBkUvpyeyyX7Mhzcw4DEoRrSHmA== X-Received: by 2002:aca:ecd4:: with SMTP id k203mr1189833oih.116.1596492914361; Mon, 03 Aug 2020 15:15:14 -0700 (PDT) Received: from posk-x1c.lan (23-118-52-46.lightspeed.sntcca.sbcglobal.net. [23.118.52.46]) by smtp.gmail.com with ESMTPSA id m8sm3026624ote.55.2020.08.03.15.15.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Aug 2020 15:15:13 -0700 (PDT) From: Peter Oskolkov To: Linux Kernel Mailing List , Thomas Gleixner , Ingo Molnar , Ingo Molnar , Peter Zijlstra , Darren Hart , Vincent Guittot Cc: Peter Oskolkov , Andrei Vagin , Paul Turner , Ben Segall , Aaron Lu Subject: [PATCH for 5.9 v2 0/4] FUTEX_SWAP (tip/locking/core) Date: Mon, 3 Aug 2020 15:15:06 -0700 Message-Id: <20200803221510.170674-1-posk@posk.io> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Oskolkov This patchset introduces FUTEX_SWAP operation for fast task context switching (aided by futexes). Detailed use cases and reasoning are included in the commit message of the first patch in the patchset. v1->v2: - split two #defines in futex.h into a small first patch - detailed the use cases and reasoning in the commit message of the first patch - renamed wake_up_process_prefer_current_cpu into wake_up_swap. Peter Oskolkov (4): futex: introduce FUTEX_SWAP operation futex: implement FUTEX_SWAP as wake+wait. futex/sched: add wake_up_swap, use in FUTEX_SWAP selftests/futex: add futex_swap selftest include/linux/sched.h | 6 + include/uapi/linux/futex.h | 2 + kernel/futex.c | 86 +++++-- kernel/sched/core.c | 5 + kernel/sched/fair.c | 3 + kernel/sched/sched.h | 1 + .../selftests/futex/functional/.gitignore | 1 + .../selftests/futex/functional/Makefile | 1 + .../selftests/futex/functional/futex_swap.c | 209 ++++++++++++++++++ .../selftests/futex/include/futextest.h | 19 ++ 10 files changed, 318 insertions(+), 15 deletions(-) create mode 100644 tools/testing/selftests/futex/functional/futex_swap.c -- 2.25.1