From patchwork Fri Feb 17 15:55:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 13144968 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 4C971C05027 for ; Fri, 17 Feb 2023 15:56:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230136AbjBQP4m (ORCPT ); Fri, 17 Feb 2023 10:56:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51742 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229736AbjBQP4k (ORCPT ); Fri, 17 Feb 2023 10:56:40 -0500 Received: from mail-io1-xd33.google.com (mail-io1-xd33.google.com [IPv6:2607:f8b0:4864:20::d33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5334271480 for ; Fri, 17 Feb 2023 07:56:10 -0800 (PST) Received: by mail-io1-xd33.google.com with SMTP id f11so371828ioz.3 for ; Fri, 17 Feb 2023 07:56:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; t=1676649369; 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=dxEL1/q2EaMAGy2jb8nUV7Ltni048cKqSOvvDVCI/cI=; b=U5Jm9FZepPr4NbBiRTI0eNo/vqmMqo3ewNSAS++5cct9FrcwNcONsk92EpvHcXC3MK /g4+nvBbKC79U/1nL1nuAbp9g3hwH0lXEP5wg7gM81lG9jUg/UJMpoEA4yGApXb4WWNy 9GpC34WlnIbgCvcF/kUnSCcr+LKkyqJ04vuxCVBfgT6VMT6K6aOu7P1C0nhehsWhxzPn 7NBPAZywLm8HQpOnbMU6GSBj/B4LONjfroxoGR8u0xPgjwCY666lchzIwUjpMdK7DyKR KOJo42GXTZ8q0xVIT8JWtMqxD5ojojp8pohiSWdwgZPsQj67dupyv4HS6jmBI3HUv93+ b5kA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1676649369; 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=dxEL1/q2EaMAGy2jb8nUV7Ltni048cKqSOvvDVCI/cI=; b=mwTtXF1/o0bq5HU5OLRuInfyCcn/cwryk0ynVpaYo7JmmlUWT5Eh0wgAN/l+AyOM7L m95n92woqm2gzxPsDGn9zLv08vw/nSCX6cOKdn01m5tmAa4Hk/38qzbo+/RZFsnItoTA 1HAV2GjIJirKwi2olHQUzEIWYtIp6q35c8sxzfCMjXDVX1i4IhRgHg8qsw1d7lU5GBXB lWvrMP629czLBKlHraU+W2PsvBIWmdxtdWHppGAS6KbzSS6lWHHD/MU1WSpuoL8m4dsP ZiNNq9gP4VsUfliX473j7jTvdzGT+RmI3U/m2++rRqQX6vEeJEdFUrfckx92AWq1t6yq l7LA== X-Gm-Message-State: AO0yUKWGzAXl74HiOgX4RqkqQ6hjYLbr1W35dhM5Q5OFoca+OFx+eEye ps+9EBmQjXCgOVtTsj6nKeRN9QQNeGEW0Yj9 X-Google-Smtp-Source: AK7set8PzalkbK9Dm7G9uluqqaDdCgzv3GE3Ru/F3WZcXM+9S3ZMhuVJQ1aqIjqTW7pEz6n8/s4EtA== X-Received: by 2002:a05:6602:2e13:b0:73a:397b:e311 with SMTP id o19-20020a0566022e1300b0073a397be311mr1633033iow.0.1676649368730; Fri, 17 Feb 2023 07:56:08 -0800 (PST) Received: from localhost.localdomain ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id d22-20020a0566022d5600b007046e9e138esm1551156iow.22.2023.02.17.07.56.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Feb 2023 07:56:08 -0800 (PST) From: Jens Axboe To: io-uring@vger.kernel.org Cc: Jens Axboe Subject: [PATCH 3/4] io_uring: cache task cancelation state in the ctx Date: Fri, 17 Feb 2023 08:55:59 -0700 Message-Id: <20230217155600.157041-4-axboe@kernel.dk> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230217155600.157041-1-axboe@kernel.dk> References: <20230217155600.157041-1-axboe@kernel.dk> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org It can be quite expensive for the fast paths to deference req->task->io_uring->in_cancel for the (very) unlikely scenario that we're currently undergoing cancelations. Add a ctx bit to indicate if we're currently canceling or not, so that the hot path may check this rather than dip into the remote task state. Signed-off-by: Jens Axboe Reviewed-by: Gabriel Krisman Bertazi --- include/linux/io_uring_types.h | 2 ++ io_uring/io_uring.c | 44 ++++++++++++++++++++++++++++++++-- 2 files changed, 44 insertions(+), 2 deletions(-) diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h index 00689c12f6ab..42d704adb9c6 100644 --- a/include/linux/io_uring_types.h +++ b/include/linux/io_uring_types.h @@ -211,6 +211,8 @@ struct io_ring_ctx { enum task_work_notify_mode notify_method; struct io_rings *rings; struct task_struct *submitter_task; + /* local ctx cache of task cancel state */ + unsigned long in_cancel; struct percpu_ref refs; } ____cacheline_aligned_in_smp; diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 64e07df034d1..0fcb532db1fc 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -3192,6 +3192,46 @@ static s64 tctx_inflight(struct io_uring_task *tctx, bool tracked) return percpu_counter_sum(&tctx->inflight); } +static __cold void io_uring_dec_cancel(struct io_uring_task *tctx, + struct io_sq_data *sqd) +{ + if (!atomic_dec_return(&tctx->in_cancel)) + return; + + if (!sqd) { + struct io_tctx_node *node; + unsigned long index; + + xa_for_each(&tctx->xa, index, node) + clear_bit(0, &node->ctx->in_cancel); + } else { + struct io_ring_ctx *ctx; + + list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) + clear_bit(0, &ctx->in_cancel); + } +} + +static __cold void io_uring_inc_cancel(struct io_uring_task *tctx, + struct io_sq_data *sqd) +{ + if (atomic_inc_return(&tctx->in_cancel) != 1) + return; + + if (!sqd) { + struct io_tctx_node *node; + unsigned long index; + + xa_for_each(&tctx->xa, index, node) + set_bit(0, &node->ctx->in_cancel); + } else { + struct io_ring_ctx *ctx; + + list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) + set_bit(0, &ctx->in_cancel); + } +} + /* * Find any io_uring ctx that this task has registered or done IO on, and cancel * requests. @sqd should be not-null IFF it's an SQPOLL thread cancellation. @@ -3210,7 +3250,7 @@ __cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd) if (tctx->io_wq) io_wq_exit_start(tctx->io_wq); - atomic_inc(&tctx->in_cancel); + io_uring_inc_cancel(tctx, sqd); do { bool loop = false; @@ -3263,7 +3303,7 @@ __cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd) * We shouldn't run task_works after cancel, so just leave * ->in_cancel set for normal exit. */ - atomic_dec(&tctx->in_cancel); + io_uring_dec_cancel(tctx, sqd); /* for exec all current's requests should be gone, kill tctx */ __io_uring_free(current); }