From: Bruce Richardson <bruce.richardson@intel.com>
To: Rafal Kozik <rk@semihalf.com>
Cc: dev@dpdk.org, mw@semihalf.com, mk@semihalf.com,
gtzalik@amazon.com, evgenys@amazon.com, matua@amazon.com,
igorch@amazon.com, ferruh.yigit@intel.com
Subject: Re: [dpdk-dev] [PATCH 0/4] support for write combining
Date: Wed, 11 Apr 2018 15:42:51 +0100 [thread overview]
Message-ID: <20180411144251.GA33124@bricha3-MOBL.ger.corp.intel.com> (raw)
In-Reply-To: <1523455637-31719-1-git-send-email-rk@semihalf.com>
On Wed, Apr 11, 2018 at 04:07:13PM +0200, Rafal Kozik wrote:
> Support for write combining.
>
> Rafal Kozik (4):
> igb_uio: add wc option
> bus/pci: reference driver structure
> eal: enable WC during resources mapping
> net/ena: enable WC
>
> drivers/bus/pci/linux/pci_uio.c | 39 ++++++++++++++++++++++++++++-----------
> drivers/bus/pci/pci_common.c | 13 ++++++++-----
> drivers/bus/pci/rte_bus_pci.h | 2 ++
> drivers/net/ena/ena_ethdev.c | 3 ++-
> kernel/linux/igb_uio/igb_uio.c | 17 ++++++++++++++---
> 5 files changed, 54 insertions(+), 20 deletions(-)
>
Couple of thoughts on this set.
You add an option to the kernel module to allow wc to be supported on a
device, but when we go to do PCI mapping, we either map the regular
resource file or the _wc one. Therefore:
1. Why not always have igb_uio support write-combining since it can be
controlled thereafter via userspace mapping one file or another?
2. Why not always map both resource and resource_wc files at the PCI level,
and make them available via different pointers to the driver? Then the
driver can choose at the per-access level which it wants to use. For
example, for init of a device, a driver may do all register access via
uncachable memory, and only use the write-combined support for
performance-critical parts. [I have a draft patch lying around here
somewhere that does something similar to that.]
One last question - if using vfio-pci kernel module, do the resource_wc
files present the bars as write-combined memory type, or are they
uncachable?
Regards,
/Bruce
next prev parent reply other threads:[~2018-04-11 14:42 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-11 14:07 Rafal Kozik
2018-04-11 14:07 ` [dpdk-dev] [PATCH 1/4] igb_uio: add wc option Rafal Kozik
2018-06-27 16:34 ` Ferruh Yigit
2018-06-28 13:08 ` Rafał Kozik
2018-06-28 13:15 ` [dpdk-dev] [PATCH v2 0/4] support for write combining Rafal Kozik
2018-06-28 13:15 ` [dpdk-dev] [PATCH v2 1/4] igb_uio: add wc option Rafal Kozik
2018-06-28 14:32 ` Ferruh Yigit
2018-06-29 8:35 ` Rafał Kozik
2018-06-29 10:08 ` Ferruh Yigit
2018-06-29 10:24 ` [dpdk-dev] [PATCH v3 0/4] support for write combining Rafal Kozik
2018-06-29 10:24 ` [dpdk-dev] [PATCH v3 1/4] igb_uio: add wc option Rafal Kozik
2018-06-29 10:53 ` Ferruh Yigit
2018-06-29 12:17 ` [dpdk-dev] [PATCH v4 0/4] Support for write combining Rafal Kozik
2018-06-29 12:17 ` [dpdk-dev] [PATCH v4 1/4] igb_uio: add wc option Rafal Kozik
2018-06-29 13:11 ` Rafał Kozik
2018-06-29 13:20 ` Ferruh Yigit
2018-06-29 13:40 ` Ferruh Yigit
2018-06-29 12:17 ` [dpdk-dev] [PATCH v4 2/4] bus/pci: reference driver structure Rafal Kozik
2018-06-29 12:17 ` [dpdk-dev] [PATCH v4 3/4] eal: enable WC during resources mapping Rafal Kozik
2018-06-29 12:17 ` [dpdk-dev] [PATCH v4 4/4] net/ena: enable WC Rafal Kozik
2018-06-29 13:54 ` [dpdk-dev] [PATCH v5 0/4] Support for write combining Rafal Kozik
2018-06-29 13:54 ` [dpdk-dev] [PATCH v5 1/4] igb_uio: add wc option Rafal Kozik
2018-06-29 13:54 ` [dpdk-dev] [PATCH v5 2/4] bus/pci: reference driver structure Rafal Kozik
2018-06-29 13:54 ` [dpdk-dev] [PATCH v5 3/4] eal: enable WC during resources mapping Rafal Kozik
2018-06-29 13:54 ` [dpdk-dev] [PATCH v5 4/4] net/ena: enable WC Rafal Kozik
2018-06-29 14:26 ` [dpdk-dev] [PATCH v5 0/4] Support for write combining Ferruh Yigit
2018-06-29 22:13 ` Thomas Monjalon
2018-06-29 10:24 ` [dpdk-dev] [PATCH v3 2/4] bus/pci: reference driver structure Rafal Kozik
2018-06-29 10:24 ` [dpdk-dev] [PATCH v3 3/4] eal: enable WC during resources mapping Rafal Kozik
2018-06-29 10:24 ` [dpdk-dev] [PATCH v3 4/4] net/ena: enable WC Rafal Kozik
2018-06-28 13:15 ` [dpdk-dev] [PATCH v2 2/4] bus/pci: reference driver structure Rafal Kozik
2018-06-28 13:15 ` [dpdk-dev] [PATCH v2 3/4] eal: enable WC during resources mapping Rafal Kozik
2018-06-28 14:50 ` Ferruh Yigit
2018-06-29 8:58 ` Rafał Kozik
2018-06-29 9:05 ` Ferruh Yigit
2018-06-29 10:28 ` Rafał Kozik
2018-06-29 10:37 ` Ferruh Yigit
2018-06-28 13:15 ` [dpdk-dev] [PATCH v2 4/4] net/ena: enable WC Rafal Kozik
2018-07-02 6:52 ` Michał Krawczyk
2018-04-11 14:07 ` [dpdk-dev] [PATCH 2/4] bus/pci: reference driver structure Rafal Kozik
2018-06-27 16:36 ` Ferruh Yigit
2018-06-28 13:05 ` Rafał Kozik
2018-04-11 14:07 ` [dpdk-dev] [PATCH 3/4] eal: enable WC during resources mapping Rafal Kozik
2018-06-27 16:41 ` Ferruh Yigit
2018-06-28 13:06 ` Rafał Kozik
2018-04-11 14:07 ` [dpdk-dev] [PATCH 4/4] net/ena: enable WC Rafal Kozik
2018-06-27 16:11 ` Thomas Monjalon
2018-06-28 13:04 ` Rafał Kozik
2018-04-11 14:42 ` Bruce Richardson [this message]
2018-04-16 11:36 ` [dpdk-dev] [PATCH 0/4] support for write combining Rafał Kozik
2018-04-27 8:27 ` Rafał Kozik
2018-04-27 11:30 ` Bruce Richardson
2018-04-30 8:07 ` Rafał Kozik
2018-04-30 8:58 ` Bruce Richardson
2018-06-11 9:32 Rafał Kozik
2018-06-26 7:27 ` Rafał Kozik
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