From nobody Wed Dec 17 10:47:59 2025 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9194C1EB18D; Mon, 12 May 2025 01:28:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747013294; cv=none; b=PVKvmHQQmtTZXP3AwCtfNZpBgKHy/Iy8nbEt+EEZ9KRbPTbz9Xzalg+DsWlqcvp8VV36AyUm/3JbA+0REsYNTP09IVQ6S8RK5yUPZc68fOSPRwz2xB6mzZdtKqWNuOJltkYlmUbvRRosJbREEiJtpJ7m3jR/tDL7ZlCtM0GMpH4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747013294; c=relaxed/simple; bh=ELvkmyOJBVEyNAiLctJDaPZmLafbprHc9jlgLasppsQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=hYVFkrqCt0tpdX1iUwLxRwa9NepXQN5qONDT8hG4Pyi4EJQNT6jgXtUi1xMFh7osCv/gJg4iTZSj2C247jMnDtNK/tc8BKTGXSgSSSTwHeSTkVGVUKWSWZ4a0bfQC6xrDUhkc+UKNfI3/psUQA/ogg7f6fOzQqwcwYc1doUNs+w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4Zwhmv3RCCz4f3lVX; Mon, 12 May 2025 09:27:43 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id A16FF1A0359; Mon, 12 May 2025 09:28:09 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgCnC2CdTiFoNFCWMA--.55093S17; Mon, 12 May 2025 09:28:09 +0800 (CST) From: Yu Kuai To: hch@lst.de, xni@redhat.com, colyli@kernel.org, agk@redhat.com, snitzer@kernel.org, mpatocka@redhat.com, song@kernel.org, yukuai3@huawei.com Cc: linux-kernel@vger.kernel.org, dm-devel@lists.linux.dev, linux-raid@vger.kernel.org, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com, johnny.chenyi@huawei.com Subject: [PATCH RFC md-6.16 v3 13/19] md/md-llbitmap: implement APIs for page level dirty bits synchronization Date: Mon, 12 May 2025 09:19:21 +0800 Message-Id: <20250512011927.2809400-14-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20250512011927.2809400-1-yukuai1@huaweicloud.com> References: <20250512011927.2809400-1-yukuai1@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: gCh0CgCnC2CdTiFoNFCWMA--.55093S17 X-Coremail-Antispam: 1UD129KBjvJXoWxAry8tF1DXF43JF18Cr4DJwb_yoW5XF15pF WxXr15Gr45tF1xWw43ArW7AFyrtr4kt39agasak34F9F1jkrZagF4xCFyDZw4UWrn5GFnr Aan8Cw1fGw48XF7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUmS14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F 4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq 3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7 IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4U M4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2 kIc2xKxwCY1x0262kKe7AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkE bVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67 AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVW8JVW5JwCI 42IY6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF 4lIxAIcVC2z280aVAFwI0_Gr0_Cr1lIxAIcVC2z280aVCY1x0267AKxVW8Jr0_Cr1UYxBI daVFxhVjvjDU0xZFpf9x0JUQFxUUUUUU= X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ Content-Type: text/plain; charset="utf-8" From: Yu Kuai IO fast path will set bits to dirty, and those dirty bits will be cleared by daemon after IO is done. llbitmap_barrier is used to synchronize between IO path and daemon; IO path: 1) try to grab a reference, if succeed, set expire time after 5s and return; 2) if failed to grab a reference, wait for daemon to finish clearing dirty bits; Daemon(Daemon will be waken up every daemon_sleep seconds): For each page: 1) check if page expired, if not skip this page; for expired page: 2) suspend the page and wait for inflight write IO to be done; 3) change dirty page to clean; 4) resume the page; Signed-off-by: Yu Kuai --- drivers/md/md-llbitmap.c | 46 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) diff --git a/drivers/md/md-llbitmap.c b/drivers/md/md-llbitmap.c index 315a4eb7627c..994ca0be3d17 100644 --- a/drivers/md/md-llbitmap.c +++ b/drivers/md/md-llbitmap.c @@ -435,6 +435,14 @@ static void llbitmap_write_page(struct llbitmap *llbit= map, int idx) } } =20 +static void active_release(struct percpu_ref *ref) +{ + struct llbitmap_barrier *barrier =3D + container_of(ref, struct llbitmap_barrier, active); + + wake_up(&barrier->wait); +} + static int llbitmap_cache_pages(struct llbitmap *llbitmap) { int nr_pages =3D (llbitmap->chunks + BITMAP_SB_SIZE + PAGE_SIZE - 1) / PA= GE_SIZE; @@ -562,3 +570,41 @@ static enum llbitmap_state llbitmap_state_machine(stru= ct llbitmap *llbitmap, =20 return state; } + +static void llbitmap_raise_barrier(struct llbitmap *llbitmap, int page_idx) +{ + struct llbitmap_barrier *barrier =3D &llbitmap->barrier[page_idx]; + +retry: + if (likely(percpu_ref_tryget_live(&barrier->active))) { + WRITE_ONCE(barrier->expire, jiffies + BARRIER_IDLE * HZ); + return; + } + + wait_event(barrier->wait, !percpu_ref_is_dying(&barrier->active)); + goto retry; +} + +static void llbitmap_release_barrier(struct llbitmap *llbitmap, int page_i= dx) +{ + struct llbitmap_barrier *barrier =3D &llbitmap->barrier[page_idx]; + + percpu_ref_put(&barrier->active); +} + +static void llbitmap_suspend(struct llbitmap *llbitmap, int page_idx) +{ + struct llbitmap_barrier *barrier =3D &llbitmap->barrier[page_idx]; + + percpu_ref_kill(&barrier->active); + wait_event(barrier->wait, percpu_ref_is_zero(&barrier->active)); +} + +static void llbitmap_resume(struct llbitmap *llbitmap, int page_idx) +{ + struct llbitmap_barrier *barrier =3D &llbitmap->barrier[page_idx]; + + barrier->expire =3D LONG_MAX; + percpu_ref_resurrect(&barrier->active); + wake_up(&barrier->wait); +} --=20 2.39.2