From patchwork Fri Jul 28 16:42:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 13332127 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 80336C04A6A for ; Fri, 28 Jul 2023 16:43:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230342AbjG1Qnf (ORCPT ); Fri, 28 Jul 2023 12:43:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233542AbjG1Qmt (ORCPT ); Fri, 28 Jul 2023 12:42:49 -0400 Received: from mail-io1-xd2c.google.com (mail-io1-xd2c.google.com [IPv6:2607:f8b0:4864:20::d2c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1B92C4200 for ; Fri, 28 Jul 2023 09:42:45 -0700 (PDT) Received: by mail-io1-xd2c.google.com with SMTP id ca18e2360f4ac-7748ca56133so22688939f.0 for ; Fri, 28 Jul 2023 09:42:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20221208.gappssmtp.com; s=20221208; t=1690562564; x=1691167364; 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=1MuKSt6kQlqZtSb725uIc8Jh1HnDCZ6mt+Wvn40Ha5c=; b=fAIW8K+ZNnNqacGBmi1BV/Ct8dW/b2LtaoE7V4bEt8sG5on/ONzNQ59wRJeKSkFcpG 45NEPqZwbglWlHr0BH4sVi7EeuXg/sv8zLaDoB8d27rcLeJGyhFobtChC2gYCkz9Rsf2 lYozv4QRpmeWwmz2lifSNOOvgbTkIxIzRrITWMUv4/Fky9EFcb0suOEW4qDqaCiLg/Oz jNtTVSn7ol3l/MSwEhxvPltOTmBVok3UdLwSLKUV6H8Aynqvno484Rc2vJ5YyPWg+M/n A6YIQnFHhj+K4cNxAduvjC1BeDF+c5HiwCi4l4SWDWbRvEe32FHoqfGcnS4LKxK/Hyah L7Sg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690562564; x=1691167364; 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=1MuKSt6kQlqZtSb725uIc8Jh1HnDCZ6mt+Wvn40Ha5c=; b=kLgagg2dTnYgTHorIThTtZkdn93vpsrPmhJCU4BILJxDxKHgchUKwtSoMr4BX0fXyZ Ve7Cs+sWgP+ZWGsHYJO6MIH9tkkDXtqSn+oJ8tFlhNskiOWioKWtxYaNWkfTzQM9G7OP 7gs0UyvaqzmvyoV9JacaYQ7gnqQOV72lOZPZ3B9SbaLkHH9EUo3ZVXBrrPJcUZ1Gfp5f ZY04haKl1p6iQ9ori0kxbuVO8bI/w8F0xHTUrFEXt9dzLk7a7w7re0d9cX5OY4rTfWea TTruuZCE6pWgmGgOjmVUa9SPF5NogNx5GJ6GA1Uxv0Ja6MZmjzSldK//GqAAEJH0MsIX a2FQ== X-Gm-Message-State: ABy/qLbFBpDg3TzIQuGuZANNeXVuG/7viREonfyfYGPYgTVRpvhQo601 iDKAXA1X2Hix9S+xcA1U0Ejfbn4bn8oIyrycJK8= X-Google-Smtp-Source: APBJJlEg49u5vRtDyYVCxZrjpChMNnKxL4+W/qibW+rwerYEZNnHxE2HplZRmK1/GvUu1TdTwc2U+Q== X-Received: by 2002:a05:6602:2b91:b0:77a:ee79:652 with SMTP id r17-20020a0566022b9100b0077aee790652mr119454iov.1.1690562564241; Fri, 28 Jul 2023 09:42:44 -0700 (PDT) Received: from localhost.localdomain ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id b2-20020a029a02000000b0042b37dda71asm1158808jal.136.2023.07.28.09.42.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Jul 2023 09:42:43 -0700 (PDT) From: Jens Axboe To: io-uring@vger.kernel.org, linux-kernel@vger.kernel.org Cc: peterz@infradead.org, andres@anarazel.de, tglx@linutronix.de, Jens Axboe Subject: [PATCH 06/12] futex: factor out the futex wake handling Date: Fri, 28 Jul 2023 10:42:29 -0600 Message-Id: <20230728164235.1318118-7-axboe@kernel.dk> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230728164235.1318118-1-axboe@kernel.dk> References: <20230728164235.1318118-1-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 | 5 +++++ kernel/futex/requeue.c | 3 ++- kernel/futex/waitwake.c | 6 +++--- 3 files changed, 10 insertions(+), 4 deletions(-) diff --git a/kernel/futex/futex.h b/kernel/futex/futex.h index 2f8deaabc9bc..bfc1e3c260b0 100644 --- a/kernel/futex/futex.h +++ b/kernel/futex/futex.h @@ -137,11 +137,15 @@ 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 * @task: the task waiting on the futex * @lock_ptr: the hash bucket lock + * @wake: the wake handler for this queue * @key: the key the futex is hashed on * @pi_state: optional priority inheritance state * @rt_waiter: rt_waiter storage for use with requeue_pi @@ -166,6 +170,7 @@ 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 fa9757766103..0272b8c3b132 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; }