From patchwork Wed Jul 12 16:20:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 13310725 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88522EB64DA for ; Wed, 12 Jul 2023 16:21:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233182AbjGLQVp (ORCPT ); Wed, 12 Jul 2023 12:21:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51934 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230344AbjGLQVc (ORCPT ); Wed, 12 Jul 2023 12:21:32 -0400 Received: from mail-io1-xd2f.google.com (mail-io1-xd2f.google.com [IPv6:2607:f8b0:4864:20::d2f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06DA92D49 for ; Wed, 12 Jul 2023 09:20:28 -0700 (PDT) Received: by mail-io1-xd2f.google.com with SMTP id ca18e2360f4ac-780c89d1998so65375339f.1 for ; Wed, 12 Jul 2023 09:20:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20221208.gappssmtp.com; s=20221208; t=1689178825; x=1689783625; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=RY5+GbYjkQ8F3AhNYX1zBu/AgfgWHjnN3p/L+7LXa1c=; b=tMY9eVMmmz14rAjujFwmQ7tYA7VhYA+ljVfRFj0f7oDFx2oXil3dyZoEITmL66l3ca B3uHHjN+lHI1xbcNSDywy3rbl0V1sDNze98IEVWF7nfpr0IwKdHab/epFZmefbqxyyOC EJkiSvROtPvLi57TDwILXVQJ45JX+80MKq1kQmyir9VReA2fXVERKLFTQCyZcAZW5TNL CTwAOANTAS1M3Dp+67LNFhUIPMa86maSCBpgl0OTed8pNeoubsdkgrT2Bj2HZ5+sIan9 fx9oA/RGMoaAWiVDXthG/XEMXTQy0I9CeOsADG9bGnvCjqe8dV+v49YfUoADHbe2+1Um e6hA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689178825; x=1689783625; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=RY5+GbYjkQ8F3AhNYX1zBu/AgfgWHjnN3p/L+7LXa1c=; b=dHhcOCqxkF0sLx9pZCLUP+uQR1Ss6lCx4BcT5/HJFtFxzJhvUhNrREGuBeN+sJd9GB 1g7aVkHCBryY39uHm8xjPqN3GIpV+5XqtPd2smD4dCAn8OpLgZ0GvQtSch2lDZMsnMx8 qVUolLJJPE6vj8PPXoyJEgHLXTpWzJOMtMuC3P6BbQOdA9POJfydg8JNW81ytFjksYi+ m5Vre+dReWnAS3wSJQsG1Ewff2iS9CIetjlro5gEsiChHLI8rQ9b9+11bu6ijrm134SE khTdixcgelAQuQCinHCKRo+cdDdxlTBP1jRgarRGE9SUn0mUSU7DpCAPOGkn7sb5Ol1v dzgQ== X-Gm-Message-State: ABy/qLYb/28qv4q0iN+j2RfJ29BJp4z8xdosn3pIHVZTo9DStoP9pn0V QiX0fGNIasObjo5kS/6xbdzFhdLhch0IP7ZI4M8= X-Google-Smtp-Source: APBJJlH0YcxQzskAZgxY8LV2IoicfMMUMCI5mn4XoDC2tqZ8SyguVPAsdbUTEPFEr82tWRgbD8IT0A== X-Received: by 2002:a05:6602:3993:b0:780:c6bb:ad8d with SMTP id bw19-20020a056602399300b00780c6bbad8dmr20527261iob.0.1689178825676; Wed, 12 Jul 2023 09:20:25 -0700 (PDT) Received: from localhost.localdomain ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id x24-20020a029718000000b0042aec33bc26sm1328775jai.18.2023.07.12.09.20.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 12 Jul 2023 09:20:24 -0700 (PDT) From: Jens Axboe To: io-uring@vger.kernel.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, peterz@infradead.org, andres@anarazel.de, Jens Axboe Subject: [PATCH 2/8] futex: factor out the futex wake handling Date: Wed, 12 Jul 2023 10:20:11 -0600 Message-Id: <20230712162017.391843-3-axboe@kernel.dk> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230712162017.391843-1-axboe@kernel.dk> References: <20230712162017.391843-1-axboe@kernel.dk> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org In preparation for having another waker that isn't futex_wake_mark(), add a wake handler in futex_q. No extra data is associated with the handler outside of struct futex_q itself. futex_wake_mark() is defined as the standard wakeup helper, now set through futex_q_init like other defaults. Normal sync futex waiting relies on wake_q holding tasks that should be woken up. This is what futex_wake_mark() does, it'll unqueue the futex and add the associated task to the wake queue. For async usage of futex waiting, rather than having tasks sleeping on the futex, we'll need to deal with a futex wake differently. For the planned io_uring case, that means posting a completion event for the task in question. Having a definable wake handler can help support that use case. Signed-off-by: Jens Axboe --- kernel/futex/futex.h | 4 ++++ kernel/futex/requeue.c | 3 ++- kernel/futex/waitwake.c | 6 +++--- 3 files changed, 9 insertions(+), 4 deletions(-) diff --git a/kernel/futex/futex.h b/kernel/futex/futex.h index b8f454792304..54b7de21ef00 100644 --- a/kernel/futex/futex.h +++ b/kernel/futex/futex.h @@ -69,6 +69,9 @@ struct futex_pi_state { union futex_key key; } __randomize_layout; +struct futex_q; +typedef void (futex_wake_fn)(struct wake_q_head *wake_q, struct futex_q *q); + /** * struct futex_q - The hashed futex queue entry, one per waiting task * @list: priority-sorted list of tasks waiting on this futex @@ -98,6 +101,7 @@ struct futex_q { struct task_struct *task; spinlock_t *lock_ptr; + futex_wake_fn *wake; union futex_key key; struct futex_pi_state *pi_state; struct rt_mutex_waiter *rt_waiter; diff --git a/kernel/futex/requeue.c b/kernel/futex/requeue.c index cba8b1a6a4cc..e892bc6c41d8 100644 --- a/kernel/futex/requeue.c +++ b/kernel/futex/requeue.c @@ -58,6 +58,7 @@ enum { const struct futex_q futex_q_init = { /* list gets initialized in futex_queue()*/ + .wake = futex_wake_mark, .key = FUTEX_KEY_INIT, .bitset = FUTEX_BITSET_MATCH_ANY, .requeue_state = ATOMIC_INIT(Q_REQUEUE_PI_NONE), @@ -591,7 +592,7 @@ int futex_requeue(u32 __user *uaddr1, unsigned int flags, u32 __user *uaddr2, /* Plain futexes just wake or requeue and are done */ if (!requeue_pi) { if (++task_count <= nr_wake) - futex_wake_mark(&wake_q, this); + this->wake(&wake_q, this); else requeue_futex(this, hb1, hb2, &key2); continue; diff --git a/kernel/futex/waitwake.c b/kernel/futex/waitwake.c index ba01b9408203..3471af87cb7d 100644 --- a/kernel/futex/waitwake.c +++ b/kernel/futex/waitwake.c @@ -174,7 +174,7 @@ int futex_wake(u32 __user *uaddr, unsigned int flags, int nr_wake, u32 bitset) if (!(this->bitset & bitset)) continue; - futex_wake_mark(&wake_q, this); + this->wake(&wake_q, this); if (++ret >= nr_wake) break; } @@ -289,7 +289,7 @@ int futex_wake_op(u32 __user *uaddr1, unsigned int flags, u32 __user *uaddr2, ret = -EINVAL; goto out_unlock; } - futex_wake_mark(&wake_q, this); + this->wake(&wake_q, this); if (++ret >= nr_wake) break; } @@ -303,7 +303,7 @@ int futex_wake_op(u32 __user *uaddr1, unsigned int flags, u32 __user *uaddr2, ret = -EINVAL; goto out_unlock; } - futex_wake_mark(&wake_q, this); + this->wake(&wake_q, this); if (++op_ret >= nr_wake2) break; }