From: Arnd Bergmann <arnd@arndb.de> To: linuxppc-dev@lists.ozlabs.org Cc: sparclinux@vger.kernel.org, paulus@samba.org, David Miller <davem@davemloft.net>, Sowmini Varadhan <sowmini.varadhan@oracle.com> Subject: Re: Generic IOMMU pooled allocator Date: Mon, 23 Mar 2015 18:45:13 +0000 [thread overview] Message-ID: <201503231945.13719.arnd@arndb.de> (raw) In-Reply-To: <1427108695.4770.227.camel@kernel.crashing.org> On Monday 23 March 2015, Benjamin Herrenschmidt wrote: > On Mon, 2015-03-23 at 07:04 +0100, Arnd Bergmann wrote: > > > > My guess is that the ARM code so far has been concerned mainly with > > getting things to work in the first place, but scalability problems > > will only be seen when there are faster CPU cores become available. > > In any case, I think this is mostly a non-issue. The complexity of the > ARM code is in various areas related to making shit work (handling > coherent allocations mostly) but only remotely related to the actual > iommu DMA space allocator (iova in ARM as far as I understand the code) > which is pretty standard. Ok, got it. Thanks for explaining tht part. > The work Sowmini is doing is about specifically the allocator. Making > our (powerpc) allocator generic since it has some nice scalability > features. > > In fact, what Aik and I have been pushing and Sowmini is close to > achieving is to mostly disconnect that allocator from the rest of the > iommu management (the caller). > > So in the end, the allocator itself should be splitable into something > separate that resides in lib/ or similar, which ARM can chose to use as > well. Yes, this sounds like a good idea. I'm currently at ELC and will bring this up with the people working on ARM IOMMU support. Arnd
WARNING: multiple messages have this Message-ID (diff)
From: Arnd Bergmann <arnd@arndb.de> To: linuxppc-dev@lists.ozlabs.org Cc: sparclinux@vger.kernel.org, paulus@samba.org, David Miller <davem@davemloft.net>, Sowmini Varadhan <sowmini.varadhan@oracle.com> Subject: Re: Generic IOMMU pooled allocator Date: Mon, 23 Mar 2015 19:45:13 +0100 [thread overview] Message-ID: <201503231945.13719.arnd@arndb.de> (raw) In-Reply-To: <1427108695.4770.227.camel@kernel.crashing.org> On Monday 23 March 2015, Benjamin Herrenschmidt wrote: > On Mon, 2015-03-23 at 07:04 +0100, Arnd Bergmann wrote: > > > > My guess is that the ARM code so far has been concerned mainly with > > getting things to work in the first place, but scalability problems > > will only be seen when there are faster CPU cores become available. > > In any case, I think this is mostly a non-issue. The complexity of the > ARM code is in various areas related to making shit work (handling > coherent allocations mostly) but only remotely related to the actual > iommu DMA space allocator (iova in ARM as far as I understand the code) > which is pretty standard. Ok, got it. Thanks for explaining tht part. > The work Sowmini is doing is about specifically the allocator. Making > our (powerpc) allocator generic since it has some nice scalability > features. > > In fact, what Aik and I have been pushing and Sowmini is close to > achieving is to mostly disconnect that allocator from the rest of the > iommu management (the caller). > > So in the end, the allocator itself should be splitable into something > separate that resides in lib/ or similar, which ARM can chose to use as > well. Yes, this sounds like a good idea. I'm currently at ELC and will bring this up with the people working on ARM IOMMU support. Arnd
next prev parent reply other threads:[~2015-03-23 18:45 UTC|newest] Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-03-19 2:25 Generic IOMMU pooled allocator David Miller 2015-03-19 2:25 ` David Miller 2015-03-19 2:46 ` Benjamin Herrenschmidt 2015-03-19 2:46 ` Benjamin Herrenschmidt 2015-03-19 2:50 ` David Miller 2015-03-19 2:50 ` David Miller 2015-03-19 3:01 ` Benjamin Herrenschmidt 2015-03-19 3:01 ` Benjamin Herrenschmidt 2015-03-19 5:27 ` Alexey Kardashevskiy 2015-03-19 5:27 ` Alexey Kardashevskiy 2015-03-19 13:34 ` Sowmini Varadhan 2015-03-19 13:34 ` Sowmini Varadhan 2015-03-22 19:27 ` Sowmini Varadhan 2015-03-22 19:27 ` Sowmini Varadhan 2015-03-23 16:29 ` David Miller 2015-03-23 16:29 ` David Miller 2015-03-23 16:54 ` Sowmini Varadhan 2015-03-23 16:54 ` Sowmini Varadhan 2015-03-23 19:05 ` David Miller 2015-03-23 19:05 ` David Miller 2015-03-23 19:09 ` Sowmini Varadhan 2015-03-23 19:09 ` Sowmini Varadhan 2015-03-23 22:21 ` Benjamin Herrenschmidt 2015-03-23 22:21 ` Benjamin Herrenschmidt 2015-03-23 23:08 ` Sowmini Varadhan 2015-03-23 23:08 ` Sowmini Varadhan 2015-03-23 23:29 ` chase rayfield 2015-03-24 0:47 ` Benjamin Herrenschmidt 2015-03-24 0:47 ` Benjamin Herrenschmidt 2015-03-24 1:11 ` Sowmini Varadhan 2015-03-24 1:11 ` Sowmini Varadhan 2015-03-24 1:44 ` David Miller 2015-03-24 1:44 ` David Miller 2015-03-24 1:57 ` Sowmini Varadhan 2015-03-24 1:57 ` Sowmini Varadhan 2015-03-24 2:08 ` Benjamin Herrenschmidt 2015-03-24 2:08 ` Benjamin Herrenschmidt 2015-03-24 2:15 ` David Miller 2015-03-24 2:15 ` David Miller 2015-03-26 0:43 ` cascardo 2015-03-26 0:43 ` cascardo 2015-03-26 0:49 ` Benjamin Herrenschmidt 2015-03-26 0:49 ` Benjamin Herrenschmidt 2015-03-26 10:56 ` Sowmini Varadhan 2015-03-26 10:56 ` Sowmini Varadhan 2015-03-26 22:51 ` David Miller 2015-03-26 23:00 ` David Miller 2015-03-26 23:51 ` Benjamin Herrenschmidt 2015-03-26 23:51 ` Benjamin Herrenschmidt 2015-03-23 22:36 ` Benjamin Herrenschmidt 2015-03-23 22:36 ` Benjamin Herrenschmidt 2015-03-23 23:19 ` Sowmini Varadhan 2015-03-23 23:19 ` Sowmini Varadhan 2015-03-24 0:48 ` Benjamin Herrenschmidt 2015-03-24 0:48 ` Benjamin Herrenschmidt 2015-03-23 22:25 ` Benjamin Herrenschmidt 2015-03-23 22:25 ` Benjamin Herrenschmidt 2015-03-22 19:36 ` Arnd Bergmann 2015-03-22 19:36 ` Arnd Bergmann 2015-03-22 22:02 ` Benjamin Herrenschmidt 2015-03-22 22:02 ` Benjamin Herrenschmidt 2015-03-22 22:07 ` Sowmini Varadhan 2015-03-22 22:07 ` Sowmini Varadhan 2015-03-22 22:22 ` Benjamin Herrenschmidt 2015-03-22 22:22 ` Benjamin Herrenschmidt 2015-03-23 6:04 ` Arnd Bergmann 2015-03-23 6:04 ` Arnd Bergmann 2015-03-23 11:04 ` Benjamin Herrenschmidt 2015-03-23 11:04 ` Benjamin Herrenschmidt 2015-03-23 18:45 ` Arnd Bergmann [this message] 2015-03-23 18:45 ` Arnd Bergmann
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