From patchwork Tue Apr 4 12:39:56 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Begunkov X-Patchwork-Id: 13199817 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 A36BAC761A6 for ; Tue, 4 Apr 2023 12:41:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234988AbjDDMlI (ORCPT ); Tue, 4 Apr 2023 08:41:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60190 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234496AbjDDMlB (ORCPT ); Tue, 4 Apr 2023 08:41:01 -0400 Received: from mail-ed1-x529.google.com (mail-ed1-x529.google.com [IPv6:2a00:1450:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4BBC31BCB; Tue, 4 Apr 2023 05:40:59 -0700 (PDT) Received: by mail-ed1-x529.google.com with SMTP id eh3so129968552edb.11; Tue, 04 Apr 2023 05:40:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680612057; 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=n5A3CaykmQoi1hwmp2XQWbZMbgV4kSoJXYsNmB3sL+Q=; b=Va0857XBhN3i/RceyFvKAGG9NyTjeRMoHgviPepMFyhspMvR5xQoNdjq6JcHUjpf28 WQmrGfLNDfk5aNTyPmbQ1sLVZGhlvo+ADJpX+iIE3O6ehr5J2yNyQU5893OVV4DQi8hF rFcfE41F0gzqJAhU996/e1mjAjhRr1n5g2vx1+BxZ4ujdJ/KY53hgLHA4lDJ+VL7Ut6G 0xNd/CH48gL4nDYivWdMqoWtnvL177k+quPFndCTV+D7B4aLnueFijUrhaWLex01WNHw QeiLlRrJqZvD9ZSL2WPV5S6hxIFY2prUFEruWMLIb927Pk0jR+YrLAfjwha2BdGLplnL TgCg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680612057; 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=n5A3CaykmQoi1hwmp2XQWbZMbgV4kSoJXYsNmB3sL+Q=; b=CaMCg7fn7xofEyxK+zgKP0FW7wE7KyqVLW79LFK/Jn2Hw0Peh6yO9tT2LUqq0LbeIr 2wPlxK83pbtK14PGrAyi0gCuiDDFteWLmQzAyS0Bgyori5ZpC5n+ztmJm+Pp4InYvfdY qTxqCPP8J54ilkTVve3Yu/6d3jRaiL6LJBEEFdVLq1bhXbvbOS6XExQeamCkdEgUKk7l yzGmlCdnJm9Sh/LpWihYnXN4O6DtDD6Vkpug/SznGCwjyVRtytu426aKLyBvgvZTJyOw hDp3s0a3+loT8odxw2kogYPyka6Be6qiGNLjEAXbOda0A9fSIiRit194rJ7parH2sCqY RnUQ== X-Gm-Message-State: AAQBX9dXIjzBvhawCEyesThhj7ytYAZzPrm0xt9/GYWyhHXMZb2X+TFx l75rEibnUxlvu4x1g7RwvFc4iKZ6vyE= X-Google-Smtp-Source: AKy350bcgGwgNQHvUCl9RKpAz/t63NcEYgt3QdivXcHIQ4llVt2OMza++p+KHQ6xZ5z8aSjREU8j3g== X-Received: by 2002:a17:907:a04e:b0:931:f132:5c61 with SMTP id gz14-20020a170907a04e00b00931f1325c61mr2130933ejc.47.1680612057264; Tue, 04 Apr 2023 05:40:57 -0700 (PDT) Received: from 127.com ([2620:10d:c092:600::2:2b22]) by smtp.gmail.com with ESMTPSA id g8-20020a170906394800b008cafeec917dsm5978851eje.101.2023.04.04.05.40.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 04 Apr 2023 05:40:56 -0700 (PDT) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: Jens Axboe , asml.silence@gmail.com, linux-kernel@vger.kernel.org Subject: [PATCH v2 12/13] io_uring/rsrc: optimise io_rsrc_data refcounting Date: Tue, 4 Apr 2023 13:39:56 +0100 Message-Id: X-Mailer: git-send-email 2.39.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Every struct io_rsrc_node takes a struct io_rsrc_data reference, which means all rsrc updates do 2 extra atomics. Replace atomics refcounting with a int as it's all done under ->uring_lock. Signed-off-by: Pavel Begunkov --- io_uring/rsrc.c | 30 ++++++++++++++++++------------ io_uring/rsrc.h | 2 +- 2 files changed, 19 insertions(+), 13 deletions(-) diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c index 95edc5f73204..74e13230fa0c 100644 --- a/io_uring/rsrc.c +++ b/io_uring/rsrc.c @@ -31,6 +31,11 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov, #define IORING_MAX_FIXED_FILES (1U << 20) #define IORING_MAX_REG_BUFFERS (1U << 14) +static inline bool io_put_rsrc_data_ref(struct io_rsrc_data *rsrc_data) +{ + return !--rsrc_data->refs; +} + int __io_account_mem(struct user_struct *user, unsigned long nr_pages) { unsigned long page_limit, cur_pages, new_pages; @@ -165,13 +170,13 @@ static void __io_rsrc_put_work(struct io_rsrc_node *ref_node) } io_rsrc_node_destroy(rsrc_data->ctx, ref_node); - if (atomic_dec_and_test(&rsrc_data->refs)) + if (io_put_rsrc_data_ref(rsrc_data)) complete(&rsrc_data->done); } void io_wait_rsrc_data(struct io_rsrc_data *data) { - if (data && !atomic_dec_and_test(&data->refs)) + if (data && !io_put_rsrc_data_ref(data)) wait_for_completion(&data->done); } @@ -234,7 +239,7 @@ void io_rsrc_node_switch(struct io_ring_ctx *ctx, rsrc_node->rsrc_data = data_to_kill; list_add_tail(&rsrc_node->node, &ctx->rsrc_ref_list); - atomic_inc(&data_to_kill->refs); + data_to_kill->refs++; /* put master ref */ io_put_rsrc_node(ctx, rsrc_node); ctx->rsrc_node = NULL; @@ -267,8 +272,8 @@ __cold static int io_rsrc_ref_quiesce(struct io_rsrc_data *data, return ret; io_rsrc_node_switch(ctx, data); - /* kill initial ref, already quiesced if zero */ - if (atomic_dec_and_test(&data->refs)) + /* kill initial ref */ + if (io_put_rsrc_data_ref(data)) return 0; data->quiesce = true; @@ -276,17 +281,19 @@ __cold static int io_rsrc_ref_quiesce(struct io_rsrc_data *data, do { ret = io_run_task_work_sig(ctx); if (ret < 0) { - atomic_inc(&data->refs); - /* wait for all works potentially completing data->done */ - reinit_completion(&data->done); mutex_lock(&ctx->uring_lock); + if (!data->refs) { + ret = 0; + } else { + /* restore the master reference */ + data->refs++; + } break; } - ret = wait_for_completion_interruptible(&data->done); if (!ret) { mutex_lock(&ctx->uring_lock); - if (atomic_read(&data->refs) <= 0) + if (!data->refs) break; /* * it has been revived by another thread while @@ -361,6 +368,7 @@ __cold static int io_rsrc_data_alloc(struct io_ring_ctx *ctx, data->nr = nr; data->ctx = ctx; data->do_put = do_put; + data->refs = 1; if (utags) { ret = -EFAULT; for (i = 0; i < nr; i++) { @@ -371,8 +379,6 @@ __cold static int io_rsrc_data_alloc(struct io_ring_ctx *ctx, goto fail; } } - - atomic_set(&data->refs, 1); init_completion(&data->done); *pdata = data; return 0; diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h index cf24c3fd701f..7ab9b2b2e757 100644 --- a/io_uring/rsrc.h +++ b/io_uring/rsrc.h @@ -33,8 +33,8 @@ struct io_rsrc_data { u64 **tags; unsigned int nr; rsrc_put_fn *do_put; - atomic_t refs; struct completion done; + int refs; bool quiesce; };