From: david.vrabel@citrix•com (David Vrabel)
To: linux-arm-kernel@lists•infradead.org
Subject: [Xen-devel] [PATCH v4 00/20] xen/arm64: Add support for 64KB page in Linux
Date: Tue, 15 Sep 2015 14:14:09 +0100 [thread overview]
Message-ID: <55F819A1.8070609@citrix.com> (raw)
In-Reply-To: <2415578.qstFX0Ux2G@wuerfel>
On 14/09/15 12:32, Arnd Bergmann wrote:
> On Monday 14 September 2015 13:04:59 Roger Pau Monn? wrote:
>>> TBH, I'm expecting a small impact to the performance. It would be hard
>>> to get the exactly the same performance as today if we keep the helpers
>>> to avoid the backend dealing himself with the splitting and page
>>> granularity.
>>>
>>> Although, if the performance impact is not acceptable, it may be
>>> possible to optimize gnttab_foreach_grant_in_range by moving the
>>> function inline. The current way to the loop is the fastest I've found
>>> (I've wrote a small program to test different way) and we will need it
>>> when different of size will be supported.
>>
>> I don't expect the performance to drop massively with this patches
>> applied, but it would be good to al least have an idea of the impact.
>
> Note that using 64kb pages in Linux tends to destroy performance
> in Linux in any case, as the memory consumption for most workloads
> explodes. In a virtualized environment you already tend to be
> memory constrained, so any measurement should take that into account
> and put the extra overhead into perspective to the massive overhead
> of running 64kb pages when RAM is tight.
If this is the case, why are some distros using 64 KiB pages then?
David
next prev parent reply other threads:[~2015-09-15 13:14 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-07 15:33 [PATCH v4 00/20] xen/arm64: Add support for 64KB page in Linux Julien Grall
2015-09-07 15:33 ` [PATCH v4 01/20] net/xen-netback: xenvif_gop_frag_copy: move GSO check out of the loop Julien Grall
2015-09-07 15:33 ` [PATCH v4 02/20] arm/xen: Drop pte_mfn and mfn_pte Julien Grall
2015-09-07 15:33 ` [PATCH v4 03/20] xen: Add Xen specific page definition Julien Grall
2015-09-07 15:33 ` [PATCH v4 04/20] xen/grant: Introduce helpers to split a page into grant Julien Grall
2015-09-07 15:33 ` [PATCH v4 05/20] xen/grant: Add helper gnttab_page_grant_foreign_access_ref_one Julien Grall
2015-09-07 15:33 ` [PATCH v4 06/20] block/xen-blkfront: Split blkif_queue_request in 2 Julien Grall
2015-09-07 15:33 ` [PATCH v4 07/20] block/xen-blkfront: Store a page rather a pfn in the grant structure Julien Grall
2015-09-07 15:33 ` [PATCH v4 08/20] block/xen-blkfront: split get_grant in 2 Julien Grall
2015-09-07 15:33 ` [PATCH v4 09/20] xen/biomerge: Don't allow biovec's to be merged when Linux is not using 4KB pages Julien Grall
2015-09-07 15:33 ` [PATCH v4 10/20] xen/xenbus: Use Xen page definition Julien Grall
2015-09-07 15:33 ` [PATCH v4 11/20] tty/hvc: xen: Use xen " Julien Grall
2015-09-07 15:33 ` [PATCH v4 12/20] xen/balloon: Don't rely on the page granularity is the same for Xen and Linux Julien Grall
2015-09-07 16:39 ` Stefano Stabellini
2015-09-07 15:33 ` [PATCH v4 13/20] xen/events: fifo: Make it running on 64KB granularity Julien Grall
2015-09-07 15:33 ` [PATCH v4 14/20] xen/grant-table: " Julien Grall
2015-09-07 15:33 ` [PATCH v4 15/20] block/xen-blkfront: Make it running on 64KB page granularity Julien Grall
2015-09-07 15:33 ` [PATCH v4 16/20] block/xen-blkback: " Julien Grall
2015-09-07 15:33 ` [PATCH v4 17/20] net/xen-netfront: " Julien Grall
2015-09-07 15:33 ` [PATCH v4 18/20] net/xen-netback: " Julien Grall
2015-09-07 16:57 ` Wei Liu
2015-09-08 11:07 ` [Xen-devel] " Julien Grall
2015-09-08 11:09 ` Wei Liu
2015-09-07 15:33 ` [PATCH v4 19/20] xen/privcmd: Add support for Linux " Julien Grall
2015-09-07 15:33 ` [PATCH v4 20/20] arm/xen: Add support for " Julien Grall
2015-09-11 19:39 ` [Xen-devel] [PATCH v4 00/20] xen/arm64: Add support for 64KB page in Linux Julien Grall
2015-09-14 8:56 ` Roger Pau Monné
2015-09-14 10:40 ` Julien Grall
2015-09-14 11:04 ` Roger Pau Monné
2015-09-14 11:21 ` Julien Grall
2015-09-14 12:08 ` Roger Pau Monné
2015-09-14 12:47 ` Julien Grall
2015-09-14 14:29 ` Roger Pau Monné
2015-09-14 14:46 ` Julien Grall
2015-09-14 14:54 ` Stefano Stabellini
2015-09-14 15:23 ` Roger Pau Monné
2015-09-22 10:59 ` Ian Campbell
2015-10-06 9:28 ` Roger Pau Monné
2015-10-06 10:17 ` Ian Campbell
2015-10-06 13:55 ` Stefano Stabellini
2015-09-18 14:10 ` Julien Grall
2015-09-14 11:32 ` Arnd Bergmann
2015-09-15 13:14 ` David Vrabel [this message]
2015-09-15 13:24 ` [Xen-devel] " Arnd Bergmann
2015-09-29 16:27 ` David Vrabel
2015-09-29 16:33 ` Julien Grall
2015-09-29 16:36 ` David Vrabel
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