From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) (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 7A32339876 for ; Mon, 22 Jan 2024 08:18:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705911532; cv=none; b=hTtst/aTXsnJG3Gpk0mrz67d1qtLXweO8wEWvy6+Oy+vQy8XuOKA+gF6blelst5SIAkbG8WxKPZeFGm7RqnA/uHo+wOGtFOryjVyHsgF+C2hBhRx0E+pXCtA2cTnoGw9wYX1p5sAE1AF+wF5cCzV4+Ue69SIW5jW1tl2X/Yna54= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705911532; c=relaxed/simple; bh=gwo3fIftUbtA1n2Eq/gu4Scek5S5zvIIa9ZtpDxoFyY=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=MIbWP1HdqLPOGYKaaM/g1xhFqnUKDTiwhXpNrmdOLbx8WyLOSoAzmTRIMovtOHNVMQo79LesQMab3BpTh8KFHooJDfc+S2AOq8zSm6QNEY7ra7D0pxrvYu5xVm0JNLs5HgNAqs2tZxVQM1dspVGyXrqwkVsRFKbkS+l4bK8i4AA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.88.194]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4TJNQT63rTzbcG5; Mon, 22 Jan 2024 16:18:25 +0800 (CST) Received: from kwepemm600020.china.huawei.com (unknown [7.193.23.147]) by mail.maildlp.com (Postfix) with ESMTPS id E4E57140499; Mon, 22 Jan 2024 16:18:47 +0800 (CST) Received: from [10.174.179.160] (10.174.179.160) by kwepemm600020.china.huawei.com (7.193.23.147) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Mon, 22 Jan 2024 16:18:46 +0800 Message-ID: Date: Mon, 22 Jan 2024 16:18:45 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Subject: Re: [PATCH] swiotlb: add debugfs to track swiotlb transient pool usage Content-Language: en-US To: , , , , , CC: , References: <20240109070456.3999739-1-zhangpeng362@huawei.com> From: "zhangpeng (AS)" In-Reply-To: <20240109070456.3999739-1-zhangpeng362@huawei.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemm600020.china.huawei.com (7.193.23.147) Kindly ping. Could someone please review this patch? Comments are welcome. Thanks. On 2024/1/9 15:04, Peng Zhang wrote: > From: ZhangPeng > > Introduce a new debugfs interface io_tlb_transient_nslabs. The device > driver can create a new swiotlb transient memory pool once default > memory pool is full. To export the swiotlb transient memory pool usage > via debugfs would help the user estimate the size of transient swiotlb > memory pool or analyze device driver memory leak issue. > > Signed-off-by: ZhangPeng > --- > include/linux/swiotlb.h | 3 +++ > kernel/dma/swiotlb.c | 46 +++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 49 insertions(+) > > diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h > index ecde0312dd52..ea23097e351f 100644 > --- a/include/linux/swiotlb.h > +++ b/include/linux/swiotlb.h > @@ -120,6 +120,8 @@ struct io_tlb_pool { > * debugfs. > * @used_hiwater: The high water mark for total_used. Used only for reporting > * in debugfs. > + * @transient_nslabs: The total number of slots in all transient pools that > + * are currently used across all areas. > */ > struct io_tlb_mem { > struct io_tlb_pool defpool; > @@ -137,6 +139,7 @@ struct io_tlb_mem { > #ifdef CONFIG_DEBUG_FS > atomic_long_t total_used; > atomic_long_t used_hiwater; > + atomic_long_t transient_nslabs; > #endif > }; > > diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c > index b079a9a8e087..77974cea3e69 100644 > --- a/kernel/dma/swiotlb.c > +++ b/kernel/dma/swiotlb.c > @@ -956,6 +956,28 @@ static void dec_used(struct io_tlb_mem *mem, unsigned int nslots) > } > #endif /* CONFIG_DEBUG_FS */ > > +#ifdef CONFIG_SWIOTLB_DYNAMIC > +#ifdef CONFIG_DEBUG_FS > +static void inc_transient_used(struct io_tlb_mem *mem, unsigned int nslots) > +{ > + atomic_long_add(nslots, &mem->transient_nslabs); > +} > + > +static void dec_transient_used(struct io_tlb_mem *mem, unsigned int nslots) > +{ > + atomic_long_sub(nslots, &mem->transient_nslabs); > +} > + > +#else /* !CONFIG_DEBUG_FS */ > +static void inc_transient_used(struct io_tlb_mem *mem, unsigned int nslots) > +{ > +} > +static void dec_transient_used(struct io_tlb_mem *mem, unsigned int nslots) > +{ > +} > +#endif /* CONFIG_DEBUG_FS */ > +#endif /* CONFIG_SWIOTLB_DYNAMIC */ > + > /** > * swiotlb_search_pool_area() - search one memory area in one pool > * @dev: Device which maps the buffer. > @@ -1170,6 +1192,7 @@ static int swiotlb_find_slots(struct device *dev, phys_addr_t orig_addr, > spin_lock_irqsave(&dev->dma_io_tlb_lock, flags); > list_add_rcu(&pool->node, &dev->dma_io_tlb_pools); > spin_unlock_irqrestore(&dev->dma_io_tlb_lock, flags); > + inc_transient_used(mem, pool->nslabs); > > found: > WRITE_ONCE(dev->dma_uses_io_tlb, true); > @@ -1415,6 +1438,7 @@ static bool swiotlb_del_transient(struct device *dev, phys_addr_t tlb_addr) > > dec_used(dev->dma_io_tlb_mem, pool->nslabs); > swiotlb_del_pool(dev, pool); > + dec_transient_used(dev->dma_io_tlb_mem, pool->nslabs); > return true; > } > > @@ -1557,6 +1581,23 @@ phys_addr_t default_swiotlb_limit(void) > } > > #ifdef CONFIG_DEBUG_FS > +#ifdef CONFIG_SWIOTLB_DYNAMIC > +static unsigned long mem_transient_used(struct io_tlb_mem *mem) > +{ > + return atomic_long_read(&mem->transient_nslabs); > +} > + > +static int io_tlb_transient_used_get(void *data, u64 *val) > +{ > + struct io_tlb_mem *mem = data; > + > + *val = mem_transient_used(mem); > + return 0; > +} > + > +DEFINE_DEBUGFS_ATTRIBUTE(fops_io_tlb_transient_used, io_tlb_transient_used_get, > + NULL, "%llu\n"); > +#endif /* CONFIG_SWIOTLB_DYNAMIC */ > > static int io_tlb_used_get(void *data, u64 *val) > { > @@ -1605,6 +1646,11 @@ static void swiotlb_create_debugfs_files(struct io_tlb_mem *mem, > &fops_io_tlb_used); > debugfs_create_file("io_tlb_used_hiwater", 0600, mem->debugfs, mem, > &fops_io_tlb_hiwater); > +#ifdef CONFIG_SWIOTLB_DYNAMIC > + atomic_long_set(&mem->transient_nslabs, 0); > + debugfs_create_file("io_tlb_transient_nslabs", 0400, mem->debugfs, > + mem, &fops_io_tlb_transient_used); > +#endif > } > > static int __init swiotlb_create_default_debugfs(void) -- Best Regards, Peng