From: Dan Williams <dan.j.williams@intel.com>
To: "Sosnowski, Maciej" <maciej.sosnowski@intel.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-raid@vger.kernel.org" <linux-raid@vger.kernel.org>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [PATCH 21/29] ioat2,3: dynamically resize descriptor ring
Date: Tue, 15 Sep 2009 16:07:05 -0700 [thread overview]
Message-ID: <e9c3a7c20909151607h5171784ence5e6722adab4ad7@mail.gmail.com> (raw)
In-Reply-To: <129600E5E5FB004392DDC3FB599660D7B5548192@irsmsx504.ger.corp.intel.com>
On Mon, Sep 14, 2009 at 8:00 AM, Sosnowski, Maciej
<maciej.sosnowski@intel.com> wrote:
> Making the max_alloc_order a module parameter gives impression
> that it can be modified by an user, including making it larger than default.
> The default is however its maximum value, which may be confusing.
> Why not to use parameter only as the upper limit?
It is the upper limit.
The user can limit the upper size of the descriptor ring by setting
this to a value less than 16. By default it is the maximum ring size
that the driver/hardware* supports. Specifying values greater than 16
are not supported by the so we need enforce a ceiling at 16.
--
Dan
* We could support ring sizes larger than 1 << 16 but we would need to
extra logic to ensure that the pending count never exceeded 1 << 16.
Simpler I think to just limit the maximum ring size.
next prev parent reply other threads:[~2009-09-15 23:07 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-04 2:30 [PATCH 00/29] ioatdma: towards raid support Dan Williams
2009-09-04 2:30 ` [PATCH 01/29] ioat: move to drivers/dma/ioat/ Dan Williams
2009-09-04 2:30 ` [PATCH 02/29] ioat: move definitions to dma.h Dan Williams
2009-09-04 2:30 ` [PATCH 03/29] ioat: convert ioat_probe to pcim/devm Dan Williams
2009-09-04 2:30 ` [PATCH 04/29] ioat: cleanup some long deref chains and 80 column collisions Dan Williams
2009-09-04 2:30 ` [PATCH 05/29] ioat: kill function prototype ifdef guards Dan Williams
2009-09-04 2:31 ` [PATCH 06/29] ioat: split ioat_dma_probe into core/version-specific routines Dan Williams
2009-09-04 2:31 ` [PATCH 07/29] ioat: fix type mismatch for ->dmacount Dan Williams
2009-09-04 2:31 ` [PATCH 08/29] ioat: define descriptor control bit-field Dan Williams
2009-09-04 2:31 ` [PATCH 09/29] ioat1: move descriptor allocation from submit to prep Dan Williams
2009-09-04 2:31 ` [PATCH 10/29] ioat: fix self test interrupts Dan Williams
2009-09-04 2:31 ` [PATCH 11/29] ioat: prepare the code for ioat[12]_dma_chan split Dan Williams
2009-09-04 2:31 ` [PATCH 12/29] ioat2,3: convert to a true ring buffer Dan Williams
2009-09-04 2:31 ` [PATCH 13/29] ioat1: kill unused unmap parameters Dan Williams
2009-09-04 2:31 ` [PATCH 14/29] ioat: add some dev_dbg() calls Dan Williams
2009-09-04 2:31 ` [PATCH 15/29] ioat: cleanup completion status reads Dan Williams
2009-09-04 2:31 ` [PATCH 16/29] ioat: ignore reserved bits for chancnt and xfercap Dan Williams
2009-09-04 2:31 ` [PATCH 17/29] ioat: preserve chanctrl bits when re-arming interrupts Dan Williams
2009-09-04 2:32 ` [PATCH 18/29] ioat: ___devinit annotate the initialization paths Dan Williams
2009-09-04 2:32 ` [PATCH 19/29] ioat1: trim ioat_dma_desc_sw Dan Williams
2009-09-14 14:55 ` Sosnowski, Maciej
2009-09-04 2:32 ` [PATCH 20/29] ioat: switch watchdog and reset handler from workqueue to timer Dan Williams
2009-09-14 14:59 ` Sosnowski, Maciej
2009-09-04 2:32 ` [PATCH 21/29] ioat2,3: dynamically resize descriptor ring Dan Williams
2009-09-14 15:00 ` Sosnowski, Maciej
2009-09-15 23:07 ` Dan Williams [this message]
2009-09-04 2:32 ` [PATCH 22/29] net_dma: poll for a descriptor after allocation failure Dan Williams
2009-09-14 15:00 ` Sosnowski, Maciej
2009-09-04 2:32 ` [PATCH 23/29] dw_dmac: implement a private tx_list Dan Williams
2009-09-04 2:32 ` [PATCH 24/29] fsldma: " Dan Williams
2009-09-04 19:42 ` Dan Williams
2009-09-04 2:32 ` [PATCH 25/29] iop-adma: " Dan Williams
2009-09-04 2:32 ` [PATCH 26/29] ioat: " Dan Williams
2009-09-14 15:01 ` Sosnowski, Maciej
2009-09-04 2:32 ` [PATCH 27/29] mv_xor: " Dan Williams
2009-09-04 2:32 ` [PATCH 28/29] dmaengine: kill tx_list Dan Williams
2009-09-14 15:01 ` Sosnowski, Maciej
2009-09-04 2:32 ` [PATCH 29/29] ioat2, 3: cacheline align software descriptor allocations Dan Williams
2009-09-14 15:02 ` Sosnowski, Maciej
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