From patchwork Wed May 19 14:13:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Begunkov X-Patchwork-Id: 12267449 X-Patchwork-Delegate: bpf@iogearbox.net 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 7322CC433B4 for ; Wed, 19 May 2021 14:14:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 52FF7611AD for ; Wed, 19 May 2021 14:14:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353970AbhESOPc (ORCPT ); Wed, 19 May 2021 10:15:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37570 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353908AbhESOPQ (ORCPT ); Wed, 19 May 2021 10:15:16 -0400 Received: from mail-wm1-x335.google.com (mail-wm1-x335.google.com [IPv6:2a00:1450:4864:20::335]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ACD58C061763; Wed, 19 May 2021 07:13:56 -0700 (PDT) Received: by mail-wm1-x335.google.com with SMTP id b7so6787134wmh.5; Wed, 19 May 2021 07:13:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=1LxYRWZUsnSIxOX2Qv7kHLFKMWp6NXKb/JCxteoPhi4=; b=ZFGdykG9VWTjZi5gupEJgX3FD/oRFvi4uH4Ko+eiMjEJW4yRLfyXH/OJiOAKd1q4yi 1+kKBEGdJuCZKkyDLC8k4uuC4JB5LU72XNU1VLdXgl+MMc0hDicBfgBiW3MTw2oI8v5g LF9Y0fHU56llWpvBOzIlBmV3TJYmQOvIv86gOmgFHgL7SsHicH7l4/XXO0/sB8y2+wlq QYPvOGnDvUEK2+u3WiCCWmeQFuoZelbGdzL1TZvLMaXNJpG2KdE63GtCBE2jbsx85zeC iIB2M/6PqCwnw9Ef11u0HUDtM2cpnrop9pzwh057QWKy+5+5G0769/BBTU1bgwlEJAoy pa1g== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=1LxYRWZUsnSIxOX2Qv7kHLFKMWp6NXKb/JCxteoPhi4=; b=nwgOcFLF/s/fod2ke37r2smu7kjjEq5pwNEIwmmeDtLSYWl/MHXnPoaqyDmSXbTeoJ 7qzNgpfQHi/i6rmrISnb6atlqPdGDreIY6FqMU+1SjUcVsJaX9YzCB9RGWTebkQdgwxh o+pl/UWmzMCUmnzYh4fhLZJmlYvW3yNxqW7v9ygdTjhIpvu8BMRo7d/0vObtgDhnY3If Nf4J6cwK2cudoLKLTY/xSSzUrTxiySo9CEsj98k3rroHMFiuO9qhLArgPQPjqvxtd++B IXUNxHBu/JW1qO8Eo7bTXB6I7LjBqiYqfF/6q5qjB5KESGNepq35PjPHCdjIATmQV8Ad BtwQ== X-Gm-Message-State: AOAM533DYoo98464gyttRladTs2UynKwDuglaFqMLXeeaHRigHBM34od hBye4HIvpR0G1U/uy4Lv4UrpALZE5JPfUbSx X-Google-Smtp-Source: ABdhPJzyGiyrMlenYIpS+THnOoIvHrkX2gj9WOMTuPD2+Qh++DG+o95t0zdKSz40zTawQlV6SgljOA== X-Received: by 2002:a05:600c:3654:: with SMTP id y20mr6103852wmq.184.1621433635073; Wed, 19 May 2021 07:13:55 -0700 (PDT) Received: from localhost.localdomain ([85.255.235.154]) by smtp.gmail.com with ESMTPSA id z3sm6233569wrq.42.2021.05.19.07.13.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 May 2021 07:13:54 -0700 (PDT) From: Pavel Begunkov To: io-uring@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jens Axboe , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Horst Schirmeier , "Franz-B . Tuneke" , Christian Dietrich Subject: [PATCH 04/23] io_uring: deduce cq_mask from cq_entries Date: Wed, 19 May 2021 15:13:15 +0100 Message-Id: X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org No need to cache cq_mask, it's exactly cq_entries - 1, so just deduce it to not carry it around. Signed-off-by: Pavel Begunkov --- fs/io_uring.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 15dc5dad1f7d..067c89e63fea 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -361,7 +361,6 @@ struct io_ring_ctx { u32 *sq_array; unsigned cached_sq_head; unsigned sq_entries; - unsigned sq_mask; unsigned sq_thread_idle; unsigned cached_sq_dropped; unsigned cached_cq_overflow; @@ -407,7 +406,6 @@ struct io_ring_ctx { struct { unsigned cached_cq_tail; unsigned cq_entries; - unsigned cq_mask; atomic_t cq_timeouts; unsigned cq_last_tm_flush; unsigned cq_extra; @@ -1363,7 +1361,7 @@ static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx) static inline struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx) { struct io_rings *rings = ctx->rings; - unsigned tail; + unsigned tail, mask = ctx->cq_entries - 1; /* * writes to the cq entry need to come after reading head; the @@ -1374,7 +1372,7 @@ static inline struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx) return NULL; tail = ctx->cached_cq_tail++; - return &rings->cqes[tail & ctx->cq_mask]; + return &rings->cqes[tail & mask]; } static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx) @@ -6677,7 +6675,7 @@ static void io_commit_sqring(struct io_ring_ctx *ctx) static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx) { u32 *sq_array = ctx->sq_array; - unsigned head; + unsigned head, mask = ctx->sq_entries - 1; /* * The cached sq head (or cq tail) serves two purposes: @@ -6687,7 +6685,7 @@ static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx) * 2) allows the kernel side to track the head on its own, even * though the application is the one updating it. */ - head = READ_ONCE(sq_array[ctx->cached_sq_head++ & ctx->sq_mask]); + head = READ_ONCE(sq_array[ctx->cached_sq_head++ & mask]); if (likely(head < ctx->sq_entries)) return &ctx->sq_sqes[head]; @@ -9493,8 +9491,6 @@ static int io_allocate_scq_urings(struct io_ring_ctx *ctx, rings->cq_ring_mask = p->cq_entries - 1; rings->sq_ring_entries = p->sq_entries; rings->cq_ring_entries = p->cq_entries; - ctx->sq_mask = rings->sq_ring_mask; - ctx->cq_mask = rings->cq_ring_mask; size = array_size(sizeof(struct io_uring_sqe), p->sq_entries); if (size == SIZE_MAX) {