From: Matthew Wilcox <willy-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
To: Tony Battersby <tonyb-vFAe+i1/wJI5UWNf+nJyDw@public.gmane.org>
Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org,
iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>,
"linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH v4 4/9] dmapool: improve scalability of dma_pool_alloc
Date: Mon, 12 Nov 2018 22:19:17 -0800 [thread overview]
Message-ID: <20181113061917.GO21824@bombadil.infradead.org> (raw)
In-Reply-To: <e982cd38-a721-bd06-8da8-0d6a0480685c-vFAe+i1/wJI5UWNf+nJyDw@public.gmane.org>
On Mon, Nov 12, 2018 at 10:43:25AM -0500, Tony Battersby wrote:
> dma_pool_alloc() scales poorly when allocating a large number of pages
> because it does a linear scan of all previously-allocated pages before
> allocating a new one. Improve its scalability by maintaining a separate
> list of pages that have free blocks ready to (re)allocate. In big O
> notation, this improves the algorithm from O(n^2) to O(n).
>
> Signed-off-by: Tony Battersby <tonyb-vFAe+i1/wJI5UWNf+nJyDw@public.gmane.org>
Acked-by: Matthew Wilcox <willy-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
prev parent reply other threads:[~2018-11-13 6:19 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-12 15:43 [PATCH v4 4/9] dmapool: improve scalability of dma_pool_alloc Tony Battersby
[not found] ` <e982cd38-a721-bd06-8da8-0d6a0480685c-vFAe+i1/wJI5UWNf+nJyDw@public.gmane.org>
2018-11-13 6:19 ` Matthew Wilcox [this message]
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