From patchwork Fri May 7 17:06:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= X-Patchwork-Id: 1475609 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=NkXVmIO2; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4FcH6y0gTFz9sXS for ; Sat, 8 May 2021 03:11:52 +1000 (AEST) Received: from localhost ([::1]:39452 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lf40z-0006Vb-HV for incoming@patchwork.ozlabs.org; Fri, 07 May 2021 13:11:49 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42970) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lf3w9-0003iB-7s for qemu-devel@nongnu.org; Fri, 07 May 2021 13:06:49 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:29427) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lf3w6-0008Pc-Ru for qemu-devel@nongnu.org; Fri, 07 May 2021 13:06:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1620407206; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IQcNAA9tRjy6cgYfLgq5D4uU843TCcUWyjVEQXH6Mlc=; b=NkXVmIO21D5oSYI5DsIxfExyPH/WeekoIP1roO22x7BMRXH5lQ6r7FLvi/JIofr6eTfcUT 4EKpl8bkjhpQW0hO3cqvZR3p/9/bHvS5DCXqjEgCKg9VZ7DQ1mKX48r29uzOwRk/bVSyXU Uj4TPIyAk1aoUzuzh9H7UNKwFKgrDm8= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-46-dgGDY_wkNO-ksvXCxe2EzA-1; Fri, 07 May 2021 13:06:43 -0400 X-MC-Unique: dgGDY_wkNO-ksvXCxe2EzA-1 Received: by mail-wm1-f70.google.com with SMTP id t6-20020a1cc3060000b0290146ea8f8661so2450166wmf.4 for ; Fri, 07 May 2021 10:06:43 -0700 (PDT) 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=IQcNAA9tRjy6cgYfLgq5D4uU843TCcUWyjVEQXH6Mlc=; b=Mo4ESsTwZriW5qJqC2qu8VZywVY2L5UrezM+KP8GRWSkTzTbttRf+CQNkfsQR7mfg2 7LhRoU690YJL+RGflSrPxo2Rpv+agell6GvLI/3jcPHmtLKDwYPdXg9muaCwrFxxV1rE GjK77hSCptpeHfG0M6huL4e6jU9vpvO6SLOPyVI1T9ufen053QPyzvelnymE0XjsSSSy uYKy2XTQSxgC9AyzI5v4HoVYExSqzAyC0K1AgXjqzAGHAX2Vjv8KntZS0dTEUB8VR7Fa OXvb43vai4OIWDL4yXh7v3R/Y1ZlFThKUeV9V7GZQoE3Rct2DxWdxeDaxsJ+axSiH9cb cE8A== X-Gm-Message-State: AOAM533fx90+/he/3/UUvNMfKVy6qNBMQ3cVmBfdNwcMjMlgZuovG0cj YkNdMv7jGAXhe5vQP3LxzqoHPP8j702IndvCd51VSQ1mCF7CffYzHosyJ7TV7KZhbcwUURs8kbo ERv0GRm+I7kAL0hgi8WfnFoSoWn2//BUFm1WY/HfB4cuDnOdcKZamztPIXq+rPpP4 X-Received: by 2002:a7b:c1c5:: with SMTP id a5mr22037117wmj.63.1620407202308; Fri, 07 May 2021 10:06:42 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwFAdms1v9lQvYAE+b4wDfhdOWIslvE9kh403/f8ZmkZXdFkfeQcaZ81vKyv82+MRMIALw0ng== X-Received: by 2002:a7b:c1c5:: with SMTP id a5mr22037090wmj.63.1620407202121; Fri, 07 May 2021 10:06:42 -0700 (PDT) Received: from localhost.localdomain (astrasbourg-652-1-219-60.w90-40.abo.wanadoo.fr. [90.40.114.60]) by smtp.gmail.com with ESMTPSA id p7sm8497070wrt.24.2021.05.07.10.06.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 May 2021 10:06:41 -0700 (PDT) From: =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= To: qemu-devel@nongnu.org Subject: [PATCH v2 1/2] bitops.h: Improve find_xxx_bit() documentation Date: Fri, 7 May 2021 19:06:33 +0200 Message-Id: <20210507170634.2058801-2-philmd@redhat.com> X-Mailer: git-send-email 2.26.3 In-Reply-To: <20210507170634.2058801-1-philmd@redhat.com> References: <20210507170634.2058801-1-philmd@redhat.com> MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=philmd@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.133.124; envelope-from=philmd@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.699, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Stefan Hajnoczi , Sergio Lopez , Richard Henderson , Max Reitz , Chai Wen , qemu-block@nongnu.org, =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Document the following functions return the bitmap size if not matching bit is found: - find_first_bit - find_next_bit - find_last_bit - find_first_zero_bit - find_next_zero_bit Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson --- include/qemu/bitops.h | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/include/qemu/bitops.h b/include/qemu/bitops.h index 3acbf3384c6..eb0fc5416a9 100644 --- a/include/qemu/bitops.h +++ b/include/qemu/bitops.h @@ -140,7 +140,8 @@ static inline int test_bit(long nr, const unsigned long *addr) * @addr: The address to start the search at * @size: The maximum size to search * - * Returns the bit number of the first set bit, or size. + * Returns the bit number of the last set bit, + * or @size if there is no set bit in the bitmap. */ unsigned long find_last_bit(const unsigned long *addr, unsigned long size); @@ -150,6 +151,9 @@ unsigned long find_last_bit(const unsigned long *addr, * @addr: The address to base the search on * @offset: The bitnumber to start searching at * @size: The bitmap size in bits + * + * Returns the bit number of the next set bit, + * or @size if there is no set bit in the bitmap. */ unsigned long find_next_bit(const unsigned long *addr, unsigned long size, @@ -160,6 +164,9 @@ unsigned long find_next_bit(const unsigned long *addr, * @addr: The address to base the search on * @offset: The bitnumber to start searching at * @size: The bitmap size in bits + * + * Returns the bit number of the next cleared bit, + * or @size if there is no clear bit in the bitmap. */ unsigned long find_next_zero_bit(const unsigned long *addr, @@ -171,7 +178,8 @@ unsigned long find_next_zero_bit(const unsigned long *addr, * @addr: The address to start the search at * @size: The maximum size to search * - * Returns the bit number of the first set bit. + * Returns the bit number of the first set bit, + * or @size if there is no set bit in the bitmap. */ static inline unsigned long find_first_bit(const unsigned long *addr, unsigned long size) @@ -194,7 +202,8 @@ static inline unsigned long find_first_bit(const unsigned long *addr, * @addr: The address to start the search at * @size: The maximum size to search * - * Returns the bit number of the first cleared bit. + * Returns the bit number of the first cleared bit, + * or @size if there is no clear bit in the bitmap. */ static inline unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size) From patchwork Fri May 7 17:06:34 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= X-Patchwork-Id: 1475608 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=UXAyQBQw; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4FcH6C4mYzz9sj5 for ; Sat, 8 May 2021 03:11:15 +1000 (AEST) Received: from localhost ([::1]:38680 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lf40P-0006Cg-Ng for incoming@patchwork.ozlabs.org; Fri, 07 May 2021 13:11:13 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:43026) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lf3wS-0004D3-O9 for qemu-devel@nongnu.org; Fri, 07 May 2021 13:07:08 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:29562) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lf3wR-00006e-99 for qemu-devel@nongnu.org; Fri, 07 May 2021 13:07:08 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1620407226; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TF0iLHO9qwO1+viQOX3X84axSRQvXosTSjRjqMFTfsA=; b=UXAyQBQw0QlorJq+FiX+tzvbZGyfRWjNMqBYmbhM23cMQ743Fyzb6vDObriF2Q/771Ybct GiwGaIoI6p5nNtJfA8/sTq4W3ztCfRREk2Pu+QH+tYAM3YYlGFYQvfYOD8aIaMdUir5dak EOTVIOwmfNwlXAaLB1IvecnMY2V84m8= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-468-vsa4iV5fOQmUj75mNQTk_Q-1; Fri, 07 May 2021 13:06:48 -0400 X-MC-Unique: vsa4iV5fOQmUj75mNQTk_Q-1 Received: by mail-wr1-f69.google.com with SMTP id s7-20020adfc5470000b0290106eef17cbdso3836831wrf.11 for ; Fri, 07 May 2021 10:06:48 -0700 (PDT) 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=TF0iLHO9qwO1+viQOX3X84axSRQvXosTSjRjqMFTfsA=; b=K63NRbkmi5okzIrD1i8VDM4fMcjeOzGAucYddimW0YNMhMYkxaXd6oQh0wtfAtBOQQ ZZqGSLI3LPpSGNb6789CoCceGHKuOhLNjc6xMr15yIt6AtYyaakL2wzwKn6939LuxIS2 GeHIjVQ0PaqXs029trwwydJUPysMAMEYtG6c/QgGWoYi4OPRV59ghLLNhUbZiVXblqqr lOV3NuGbyfiwKH0sAy3RyVd2kb74HDuIMFEr3oebEn5pYs2l8fi+z24cMCIGMwAvozkk fGwduUUEUZqeR0D6SwOznkhB3w1Jbsgz2FpiP/VNYtlnbPsd2w5bYYLGXkM2yGdwpeiY 3I2g== X-Gm-Message-State: AOAM530+2QZ+XjlNmkMJuw2r1nLAoHEDurcoasDgQa/QR9K0j4E7xF8p RDSu69L2p16jRWBR0pjObPWBzq5f0jRMQCh6P8gQNKpoweJcv2kRJCrroCmsvw1QwdJNO7SfEx0 J0tPUTXdDOUydejPyqJbFyO/ZjfcokGty2JMiHFrOn9OpLM69+T9LuOmaE1jdBVLN X-Received: by 2002:a05:6000:2ae:: with SMTP id l14mr13506915wry.155.1620407207402; Fri, 07 May 2021 10:06:47 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwbf9ADvINobrWZo84yL0kff1ES6G2m/29bDAW0KEuwQL1PbIpPAdj/kGaXO7JdC9CfRf1N6Q== X-Received: by 2002:a05:6000:2ae:: with SMTP id l14mr13506869wry.155.1620407207018; Fri, 07 May 2021 10:06:47 -0700 (PDT) Received: from localhost.localdomain (astrasbourg-652-1-219-60.w90-40.abo.wanadoo.fr. [90.40.114.60]) by smtp.gmail.com with ESMTPSA id o13sm8369179wrf.91.2021.05.07.10.06.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 May 2021 10:06:46 -0700 (PDT) From: =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= To: qemu-devel@nongnu.org Subject: [PATCH v2 2/2] virtio-blk: Convert QEMUBH callback to "bitops.h" API Date: Fri, 7 May 2021 19:06:34 +0200 Message-Id: <20210507170634.2058801-3-philmd@redhat.com> X-Mailer: git-send-email 2.26.3 In-Reply-To: <20210507170634.2058801-1-philmd@redhat.com> References: <20210507170634.2058801-1-philmd@redhat.com> MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=philmd@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.133.124; envelope-from=philmd@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.699, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Stefan Hajnoczi , Sergio Lopez , Richard Henderson , Max Reitz , Chai Wen , qemu-block@nongnu.org, =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" By directly using find_first_bit() and find_next_bit from the "bitops.h" API to iterate over the bitmap, we can remove the bitmap[] variable-length array copy on the stack and the complex manual bit testing/clearing logic. Suggested-by: Stefan Hajnoczi Suggested-by: Richard Henderson Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson --- hw/block/dataplane/virtio-blk.c | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-) diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c index e9050c8987e..a7b5bda06fc 100644 --- a/hw/block/dataplane/virtio-blk.c +++ b/hw/block/dataplane/virtio-blk.c @@ -60,23 +60,12 @@ static void notify_guest_bh(void *opaque) { VirtIOBlockDataPlane *s = opaque; unsigned nvqs = s->conf->num_queues; - unsigned long bitmap[BITS_TO_LONGS(nvqs)]; - unsigned j; - memcpy(bitmap, s->batch_notify_vqs, sizeof(bitmap)); - memset(s->batch_notify_vqs, 0, sizeof(bitmap)); + for (unsigned long i = find_first_bit(s->batch_notify_vqs, nvqs); + i < nvqs; i = find_next_bit(s->batch_notify_vqs, nvqs, i)) { + VirtQueue *vq = virtio_get_queue(s->vdev, i); - for (j = 0; j < nvqs; j += BITS_PER_LONG) { - unsigned long bits = bitmap[j / BITS_PER_LONG]; - - while (bits != 0) { - unsigned i = j + ctzl(bits); - VirtQueue *vq = virtio_get_queue(s->vdev, i); - - virtio_notify_irqfd(s->vdev, vq); - - bits &= bits - 1; /* clear right-most bit */ - } + virtio_notify_irqfd(s->vdev, vq); } }