From: Christoph Hellwig <hch@lst.de>
To: Robin Murphy <robin.murphy@arm.com>
Cc: hch@lst.de, m.szyprowski@samsung.com,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
cai@gmx.us, salil.mehta@huawei.com, john.garry@huawei.com
Subject: Re: [RFC 4/4] dma-debug: Make leak-like behaviour apparent
Date: Tue, 4 Dec 2018 15:31:06 +0100 [thread overview]
Message-ID: <20181204143106.GD2767@lst.de> (raw)
In-Reply-To: <7ec928f0bd92122f271c421e99aaeb593ccabdf5.1543856576.git.robin.murphy@arm.com>
On Mon, Dec 03, 2018 at 05:28:09PM +0000, Robin Murphy wrote:
> Now that we can dynamically allocate DMA debug entries to cope with
> drivers maintaining excessively large numbers of live mappings, a driver
> which *does* actually have a bug leaking mappings (and is not unloaded)
> will no longer trigger the "DMA-API: debugging out of memory - disabling"
> message until it gets to actual kernel OOM conditions, which means it
> could go unnoticed for a while. To that end, let's inform the user each
> time the pool has grown to a multiple of its initial size, which should
> make it apparent that they either have a leak or might want to increase
> the preallocation size.
>
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
>
> Tagging this one as RFC since people might think it's silly.
I think finding out the numbers is useful, but I'm a little worried
about claiming a possible leak. Maybe we just need to print a log message
for each new power of 2 of entries reached?
next prev parent reply other threads:[~2018-12-04 14:31 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-03 17:28 [PATCH 0/4] dma-debug: implement dynamic entry allocation Robin Murphy
2018-12-03 17:28 ` [PATCH 1/4] dma-debug: Use pr_fmt() Robin Murphy
2018-12-04 14:26 ` Christoph Hellwig
2018-12-04 17:35 ` Joe Perches
2018-12-03 17:28 ` [PATCH 2/4] dma-debug: Refactor dma_debug_entry allocation Robin Murphy
2018-12-04 14:27 ` Christoph Hellwig
2018-12-04 16:09 ` Robin Murphy
2018-12-03 17:28 ` [PATCH 3/4] dma-debug: Dynamically expand the dma_debug_entry pool Robin Murphy
2018-12-03 18:23 ` John Garry
2018-12-04 13:11 ` Robin Murphy
2018-12-04 14:17 ` Christoph Hellwig
2018-12-04 16:06 ` Robin Murphy
2018-12-04 16:30 ` John Garry
2018-12-04 17:19 ` Robin Murphy
2018-12-04 17:38 ` John Garry
2018-12-04 14:29 ` Christoph Hellwig
2018-12-04 16:32 ` Robin Murphy
2018-12-03 17:28 ` [RFC 4/4] dma-debug: Make leak-like behaviour apparent Robin Murphy
2018-12-04 14:31 ` Christoph Hellwig [this message]
2018-12-03 17:34 ` [PATCH 0/4] dma-debug: implement dynamic entry allocation Christoph Hellwig
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