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From: Shaohua Li <shli-b10kYP2dOMg@public.gmane.org>
To: "Woodhouse,
	David" <david.woodhouse-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org"
	<iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>,
	"jroedel-l3A5Bk7waGM@public.gmane.org"
	<jroedel-l3A5Bk7waGM@public.gmane.org>,
	"Kernel-team-b10kYP2dOMg@public.gmane.org"
	<Kernel-team-b10kYP2dOMg@public.gmane.org>
Subject: Re: [PATCH 2/4] iommu: add a bitmap based dma address allocator
Date: Tue, 24 Nov 2015 14:05:12 -0800	[thread overview]
Message-ID: <20151124220511.GA2106568@devbig084.prn1.facebook.com> (raw)
In-Reply-To: <1448402209.44976.109.camel-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

On Tue, Nov 24, 2015 at 09:56:50PM +0000, Woodhouse, David wrote:
> On Tue, 2015-11-24 at 13:54 -0800, Shaohua Li wrote:
> > 
> > This patch introduces a bitmap based allocator.
> 
> Why not just use the one in lib/iommu-common.c? I'd like to see
> intel-iommu completely drop the iova.c code.

The lib/iommu-common.c uses a bitmap and a lock. This implementation
actually uses a percpu_ida which completely avoids locking. It would be
possible to make lib/iommu-common.c use percpu_ida too if somebody wants
to do it, but I think this shouldn't be a blocker for these patches
giving it has huge performance gain.

Thanks,
Shaohua

  parent reply	other threads:[~2015-11-24 22:05 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-24 21:54 [PATCH 0/4] iommu: remove lock contention in iova allocation Shaohua Li
     [not found] ` <cover.1448401089.git.shli-b10kYP2dOMg@public.gmane.org>
2015-11-24 21:54   ` [PATCH 1/4] iommu: alloc_iova returns a pfn Shaohua Li
2015-11-24 21:54   ` [PATCH 2/4] iommu: add a bitmap based dma address allocator Shaohua Li
     [not found]     ` <4c0804c85404be81acfe81fcd402f1af484e9d5f.1448401089.git.shli-b10kYP2dOMg@public.gmane.org>
2015-11-24 21:56       ` Woodhouse, David
     [not found]         ` <1448402209.44976.109.camel-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2015-11-24 22:05           ` Shaohua Li [this message]
     [not found]             ` <20151124220511.GA2106568-tb7CFzD8y5b7E6g3fPdp/g2O0Ztt9esIQQ4Iyu8u01E@public.gmane.org>
2015-11-25 14:46               ` jroedel-l3A5Bk7waGM
     [not found]                 ` <20151125144613.GA3763-l3A5Bk7waGM@public.gmane.org>
2015-11-25 16:40                   ` Woodhouse, David
     [not found]                     ` <1448469599.44976.134.camel-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2015-11-25 16:43                       ` Jens Axboe
     [not found]                         ` <5655E545.1010509-b10kYP2dOMg@public.gmane.org>
2015-11-25 17:33                           ` Shaohua Li
     [not found]                             ` <20151125173320.GA92074-tb7CFzD8y5b7E6g3fPdp/g2O0Ztt9esIQQ4Iyu8u01E@public.gmane.org>
2015-11-25 17:38                               ` Jens Axboe
     [not found]                                 ` <5655F1F8.9070203-b10kYP2dOMg@public.gmane.org>
2015-11-25 18:57                                   ` Shaohua Li
2015-11-24 21:54   ` [PATCH 3/4] iommu: enable bitmap allocation for intel iommu Shaohua Li
2015-11-24 21:54   ` [PATCH 4/4] iommu: free_iova doesn't need lock twice Shaohua Li
2015-12-07 17:52   ` [PATCH 0/4] iommu: remove lock contention in iova allocation Shaohua Li

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