From: Bruce Richardson <bruce.richardson@intel.com>
To: Tony Lu <zlu@ezchip.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v3 08/12] mempool: allow config override on element alignment
Date: Tue, 7 Jul 2015 11:10:31 +0100 [thread overview]
Message-ID: <20150707101031.GA7040@bricha3-MOBL3> (raw)
In-Reply-To: <000f01d0b895$8ccbf8c0$a663ea40$@com>
On Tue, Jul 07, 2015 at 05:15:41PM +0800, Tony Lu wrote:
>
>
> >-----Original Message-----
> >From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Bruce Richardson
> >Sent: Monday, July 06, 2015 11:38 PM
> >To: Zhigang Lu
> >Cc: dev@dpdk.org
> >Subject: Re: [dpdk-dev] [PATCH v3 08/12] mempool: allow config override on
> >element alignment
> >
> >On Mon, Jul 06, 2015 at 04:51:33PM +0800, Zhigang Lu wrote:
> >> On TILE-Gx and TILE-Mx platforms, the buffers fed into the hardware
> >> buffer manager require a 128-byte alignment. With this change, we
> >> allow configuration based override of the element alignment, and
> >> default to RTE_CACHE_LINE_SIZE if left unspecified.
> >>
> >> Change-Id: I9cd789d92b0bc9c8f44a633de59bb04d45d927a7
> >> Signed-off-by: Zhigang Lu <zlu@ezchip.com>
> >
> >This looks an OK change. However, would it be worthwhile making this a
> runtime
> >parameter rather than a compile-time one? Is it likely that we will ever
> have a
> >case where someone wants two mempools with different alignments (and
> >where using the larger of the two would be problematic)?
>
> For now, I don't think it is very much worthwhile making this a runtime
> parameter,
> since doing so requires changing the mempool library API, and also the users
> of mempool
> do not quite care about the underlying alignments. Currently, the alignment
> for mempool
> objects is mostly a hardware requirement (currently RTE_CACHE_LINE_SIZE for
> good
> performance). And now we are defining a new RTE_MEMPOOL_ALIGN for mempool
> alignment requirement for cases where someone needs other alignments than
> RTE_CACHE_LINE_SIZE.
>
> If someone wants two mempools with different alignments, using the larger
> one would
> not be a problem in current mempool implementation. Because even for the
> case where
> there is one alignment requirement RTE_CACHE_LINE_SIZE, we would provide
> larger one
> (2* RTE_CACHE_LINE_SIZE and larger) for allocated mempool objects, as those
> objects
> are continuous in memory. So we could not avoid larger one in current
> implementation.
>
> Thanks again for reviewing!
> -Zhigang
>
> >/Bruce
>
Ok, makes sense.
/Bruce
next prev parent reply other threads:[~2015-07-07 10:10 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-06 8:51 [dpdk-dev] [PATCH v3 00/12] Introducing the TILE-Gx platform Zhigang Lu
2015-07-06 8:51 ` [dpdk-dev] [PATCH v3 01/12] test: limit x86 cpuflags checks to x86 builds Zhigang Lu
2015-07-06 10:53 ` Bruce Richardson
2015-07-07 8:21 ` Tony Lu
2015-07-06 8:51 ` [dpdk-dev] [PATCH v3 02/12] hash: fix compilation on non-X86 platforms Zhigang Lu
2015-07-06 11:15 ` Bruce Richardson
2015-07-07 8:24 ` Tony Lu
2015-07-07 14:52 ` Sanford, Robert
2015-07-08 8:21 ` Tony Lu
2015-07-06 8:51 ` [dpdk-dev] [PATCH v3 03/12] hash: check SSE flags only on x86 builds Zhigang Lu
2015-07-06 15:32 ` Bruce Richardson
2015-07-06 8:51 ` [dpdk-dev] [PATCH v3 04/12] eal: allow empty compile time flags Zhigang Lu
2015-07-06 15:33 ` Bruce Richardson
2015-07-09 0:46 ` Thomas Monjalon
2015-07-09 4:20 ` Tony Lu
2015-07-09 6:49 ` damu
2015-07-06 8:51 ` [dpdk-dev] [PATCH v3 05/12] config: remove RTE_LIBNAME definition Zhigang Lu
2015-07-06 15:34 ` Bruce Richardson
2015-07-06 8:51 ` [dpdk-dev] [PATCH v3 06/12] memzone: refactor rte_memzone_reserve() variants Zhigang Lu
2015-07-09 0:51 ` Thomas Monjalon
2015-07-06 8:51 ` [dpdk-dev] [PATCH v3 07/12] memzone: allow multiple pagesizes to be requested Zhigang Lu
2015-07-06 8:51 ` [dpdk-dev] [PATCH v3 08/12] mempool: allow config override on element alignment Zhigang Lu
2015-07-06 15:37 ` Bruce Richardson
2015-07-07 9:15 ` Tony Lu
2015-07-07 10:10 ` Bruce Richardson [this message]
2015-07-06 8:51 ` [dpdk-dev] [PATCH v3 09/12] tile: add page sizes for TILE-Gx/Mx platforms Zhigang Lu
2015-07-06 8:51 ` [dpdk-dev] [PATCH v3 10/12] tile: initial TILE-Gx support Zhigang Lu
2015-07-06 8:51 ` [dpdk-dev] [PATCH v3 11/12] tile: Add TILE-Gx mPIPE poll mode driver Zhigang Lu
2015-07-06 8:51 ` [dpdk-dev] [PATCH v3 12/12] maintainers: claim responsibility for TILE-Gx platform Zhigang Lu
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