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From: julien.grall@citrix•com (Julien Grall)
To: linux-arm-kernel@lists•infradead.org
Subject: [Xen-devel] [PATCH v2 13/20] xen/events: fifo: Make it running on 64KB granularity
Date: Thu, 16 Jul 2015 17:18:29 +0100	[thread overview]
Message-ID: <55A7D955.5090203@citrix.com> (raw)
In-Reply-To: <alpine.DEB.2.02.1507161642130.17378@kaball.uk.xensource.com>

Hi Stefano,

On 16/07/2015 16:43, Stefano Stabellini wrote:
> On Thu, 9 Jul 2015, Julien Grall wrote:
>> Only use the first 4KB of the page to store the events channel info. It
>> means that we will wast 60KB every time we allocate page for:
>                        ^ waste
>
>>       * control block: a page is allocating per CPU
>>       * event array: a page is allocating everytime we need to expand it
>>
>> I think we can reduce the memory waste for the 2 areas by:
>>
>>      * control block: sharing between multiple vCPUs. Although it will
>>      require some bookkeeping in order to not free the page when the CPU
>>      goes offline and the other CPUs sharing the page still there
>>
>>      * event array: always extend the array event by 64K (i.e 16 4K
>>      chunk). That would require more care when we fail to expand the
>>      event channel.
>
> But this is not implemented in this series, right?

Yes, it's some ideas to improve the code.

>
>
>> Signed-off-by: Julien Grall <julien.grall@citrix•com>
>> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle•com>
>> Cc: Boris Ostrovsky <boris.ostrovsky@oracle•com>
>> Cc: David Vrabel <david.vrabel@citrix•com>
>> ---
>>   drivers/xen/events/events_base.c | 2 +-
>>   drivers/xen/events/events_fifo.c | 2 +-
>>   2 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
>> index 96093ae..858d2f6 100644
>> --- a/drivers/xen/events/events_base.c
>> +++ b/drivers/xen/events/events_base.c
>> @@ -40,11 +40,11 @@
>>   #include <asm/idle.h>
>>   #include <asm/io_apic.h>
>>   #include <asm/xen/pci.h>
>> -#include <xen/page.h>
>>   #endif
>>   #include <asm/sync_bitops.h>
>>   #include <asm/xen/hypercall.h>
>>   #include <asm/xen/hypervisor.h>
>> +#include <xen/page.h>
>>
>>   #include <xen/xen.h>
>>   #include <xen/hvm.h>
>
> Spurious change?

No, xen/page.h was only included for x86 before. Now, it's included for 
every architecture.

This is required in order to get XEN_PAGE_SIZE.

Regards,

-- 
Julien Grall

  reply	other threads:[~2015-07-16 16:18 UTC|newest]

Thread overview: 87+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-09 20:42 [PATCH v2 00/20] xen/arm64: Add support for 64KB page Julien Grall
2015-07-09 20:42 ` [PATCH v2 01/20] xen: Add Xen specific page definition Julien Grall
2015-07-16 14:19   ` Stefano Stabellini
2015-07-16 14:52     ` Julien Grall
2015-07-24  9:28   ` [Xen-devel] " David Vrabel
2015-07-24  9:39     ` Julien Grall
2015-07-24  9:48       ` David Vrabel
2015-07-24  9:51         ` Julien Grall
2015-07-24 10:34           ` David Vrabel
2015-07-24 10:43             ` Ian Campbell
2015-07-24 13:03             ` Julien Grall
2015-07-09 20:42 ` [PATCH v2 02/20] xen: Introduce a function to split a Linux page into Xen page Julien Grall
2015-07-16 14:23   ` Stefano Stabellini
2015-07-16 14:54     ` [Xen-devel] " Julien Grall
2015-07-24  9:31   ` David Vrabel
2015-07-24  9:54     ` Julien Grall
2015-07-24 10:10       ` David Vrabel
2015-07-24 10:20         ` Julien Grall
2015-08-05 14:30         ` Julien Grall
2015-08-05 15:50           ` David Vrabel
2015-08-05 16:06             ` Julien Grall
2015-07-09 20:42 ` [PATCH v2 03/20] xen/grant: Introduce helpers to split a page into grant Julien Grall
2015-07-16 15:01   ` Stefano Stabellini
2015-07-16 16:07     ` Julien Grall
2015-07-17 13:10       ` [Xen-devel] " Julien Grall
2015-07-09 20:42 ` [PATCH v2 04/20] xen/grant: Add helper gnttab_page_grant_foreign_access_ref Julien Grall
2015-07-16 15:05   ` Stefano Stabellini
2015-07-16 16:12     ` [Xen-devel] " Julien Grall
2015-07-24  9:35   ` David Vrabel
2015-07-09 20:42 ` [PATCH v2 05/20] block/xen-blkfront: Split blkif_queue_request in 2 Julien Grall
2015-07-21  9:54   ` Roger Pau Monné
2015-07-21 11:12     ` [Xen-devel] " Julien Grall
2015-07-09 20:42 ` [PATCH v2 06/20] block/xen-blkfront: Store a page rather a pfn in the grant structure Julien Grall
2015-07-16 15:11   ` Stefano Stabellini
2015-07-23 17:18     ` Julien Grall
2015-07-21 10:16   ` Roger Pau Monné
2015-07-21 11:19     ` [Xen-devel] " Julien Grall
2015-07-09 20:42 ` [PATCH v2 07/20] block/xen-blkfront: split get_grant in 2 Julien Grall
2015-07-21 10:30   ` Roger Pau Monné
2015-07-21 13:03     ` [Xen-devel] " Julien Grall
2015-07-09 20:42 ` [PATCH v2 08/20] net/xen-netback: xenvif_gop_frag_copy: move GSO check out of the loop Julien Grall
2015-07-09 20:42 ` [PATCH v2 09/20] xen/biomerge: Don't allow biovec to be merge when Linux is not using 4KB page Julien Grall
2015-07-10 19:12   ` Konrad Rzeszutek Wilk
2015-07-15  8:56     ` [Xen-devel] " Julien Grall
2015-07-16 15:33     ` Stefano Stabellini
2015-07-16 16:15       ` [Xen-devel] " Julien Grall
2015-07-16 18:30         ` Konrad Rzeszutek Wilk
2015-07-17 13:20         ` Stefano Stabellini
2015-07-17 14:44           ` Julien Grall
2015-07-17 14:45             ` Stefano Stabellini
2015-07-17 14:46               ` Julien Grall
2015-07-09 20:42 ` [PATCH v2 10/20] xen/xenbus: Use Xen page definition Julien Grall
2015-07-16 15:35   ` Stefano Stabellini
2015-07-24  9:49   ` David Vrabel
2015-07-09 20:42 ` [PATCH v2 11/20] tty/hvc: xen: Use xen " Julien Grall
2015-07-16 15:36   ` Stefano Stabellini
2015-07-24  9:52   ` David Vrabel
2015-07-09 20:42 ` [PATCH v2 12/20] xen/balloon: Don't rely on the page granularity is the same for Xen and Linux Julien Grall
2015-07-17 14:03   ` Stefano Stabellini
2015-07-17 14:32     ` Julien Grall
2015-07-09 20:42 ` [PATCH v2 13/20] xen/events: fifo: Make it running on 64KB granularity Julien Grall
2015-07-16 15:43   ` Stefano Stabellini
2015-07-16 16:18     ` Julien Grall [this message]
2015-07-17 13:06       ` [Xen-devel] " Stefano Stabellini
2015-07-24 10:36   ` David Vrabel
2015-08-06 15:43     ` [Xen-devel] " Julien Grall
2015-07-09 20:42 ` [PATCH v2 14/20] xen/grant-table: " Julien Grall
2015-07-16 15:47   ` Stefano Stabellini
2015-07-16 16:23     ` [Xen-devel] " Julien Grall
2015-07-17 13:37       ` Stefano Stabellini
2015-07-09 20:42 ` [PATCH v2 15/20] block/xen-blkfront: Make it running on 64KB page granularity Julien Grall
2015-07-21 11:06   ` Roger Pau Monné
2015-07-21 13:07     ` [Xen-devel] " Julien Grall
2015-07-09 20:42 ` [PATCH v2 16/20] block/xen-blkback: " Julien Grall
2015-07-09 20:42 ` [PATCH v2 17/20] net/xen-netfront: " Julien Grall
2015-07-20 17:26   ` [Xen-devel] " Julien Grall
2015-07-09 20:42 ` [PATCH v2 18/20] net/xen-netback: " Julien Grall
2015-07-09 20:42 ` [PATCH v2 19/20] xen/privcmd: Add support for Linux " Julien Grall
2015-07-13 20:13   ` Boris Ostrovsky
2015-07-13 22:05     ` Julien Grall
2015-07-14 15:28       ` Boris Ostrovsky
2015-07-14 15:37         ` Julien Grall
2015-07-16 17:12   ` Stefano Stabellini
2015-07-16 17:16     ` Stefano Stabellini
2015-07-17 12:50     ` [Xen-devel] " Julien Grall
2015-07-09 20:42 ` [PATCH v2 20/20] arm/xen: Add support for " Julien Grall
2015-07-20 17:54 ` [Xen-devel] [PATCH v2 00/20] xen/arm64: Add support for 64KB page Julien Grall

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