From: Christoph Hellwig <hch@infradead.org>
To: "Thomas Hellström (VMware)" <thomas_os@shipmail.org>
Cc: Christoph Hellwig <hch@infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: dma api errors with swiotlb
Date: Wed, 4 Sep 2019 05:55:38 -0700 [thread overview]
Message-ID: <20190904125538.GA30177@infradead.org> (raw)
In-Reply-To: <4e21951d-025a-2b3d-14c8-878c6f237525@shipmail.org>
On Wed, Sep 04, 2019 at 02:54:26PM +0200, Thomas Hellström (VMware) wrote:
> On 9/4/19 2:17 PM, Christoph Hellwig wrote:
> > A call to dma_max_mapping_size() to limit the maximum I/O size solves
> > that problem. With the latest kernel that should actually be done
> > automatically by the SCSI midlayer for you.
>
> Hmm, OK. I guess with a sufficient queue depth and many mappings waiting for
> DMA completion, the SWIOTLB may fill up anyway...
>
> I'll see if I can come up with something.
You are supposed to return SCSI_MLQUEUE_HOST_BUSY in that case,
which means that the kernel won't send more commands until another
one completed.
next prev parent reply other threads:[~2019-09-04 12:55 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-04 7:59 dma api errors with swiotlb Thomas Hellström (VMware)
2019-09-04 12:17 ` Christoph Hellwig
2019-09-04 12:54 ` Thomas Hellström (VMware)
2019-09-04 12:55 ` Christoph Hellwig [this message]
2019-09-04 13:02 ` Thomas Hellström (VMware)
2019-09-04 13:16 ` Christoph Hellwig
2019-09-04 13:21 ` Thomas Hellström (VMware)
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