From: "Marc-André Lureau" <marcandre.lureau@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Sergio Lopez Pascual <slp@redhat.com>,
Baoquan He <bhe@redhat.com>, "Somlo, Gabriel" <somlo@cmu.edu>,
xiaolong.ye@intel.com
Subject: Re: [PATCH v15 11/11] RFC: fw_cfg: do DMA read operation
Date: Wed, 28 Feb 2018 17:00:58 +0100 [thread overview]
Message-ID: <CAMxuvaw-v3BagJ6-50sxW24X3c=S-4Xfd5e1Unq8ScNbxKvkSQ@mail.gmail.com> (raw)
In-Reply-To: <20180228174635-mutt-send-email-mst@kernel.org>
Hi
On Wed, Feb 28, 2018 at 4:48 PM, Michael S. Tsirkin <mst@redhat.com> wrote:
> On Wed, Feb 28, 2018 at 04:41:51PM +0100, Marc-André Lureau wrote:
>> I don't know if it's always safe to enable dma in read_raw(), how
>> could we know? Is there a check we could use to choose one or ther
>> other (and thus avoiding explicit dma/readfn argument)?
>
> I'm not sure - but does it really matter? Is anyone reading large files
> like this in production where speed matters?
> Why even bother with DMA?
The difference is quite significante for not so small files, as shown above.
And if they access the fw_cfg entries at boot time, or when starting
things etc, this may speed things up.
next prev parent reply other threads:[~2018-02-28 16:01 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-15 21:33 [PATCH v15 00/11] fw_cfg: add DMA operations & etc/vmcoreinfo support Marc-André Lureau
2018-02-15 21:33 ` [PATCH v15 01/11] crash: export paddr_vmcoreinfo_note() Marc-André Lureau
2018-02-15 21:33 ` [PATCH v15 02/11] fw_cfg: add a public uapi header Marc-André Lureau
2018-02-27 0:06 ` Michael S. Tsirkin
2018-02-28 11:50 ` Marc-André Lureau
2018-02-15 21:33 ` [PATCH v15 03/11] fw_cfg: fix sparse warnings in fw_cfg_sel_endianness() Marc-André Lureau
2018-02-15 21:33 ` [PATCH v15 04/11] fw_cfg: fix sparse warnings with fw_cfg_file Marc-André Lureau
2018-02-15 21:33 ` [PATCH v15 05/11] fw_cfg: fix sparse warning reading FW_CFG_ID Marc-André Lureau
2018-02-15 21:33 ` [PATCH v15 06/11] fw_cfg: fix sparse warnings around FW_CFG_FILE_DIR read Marc-André Lureau
2018-02-15 21:33 ` [PATCH v15 07/11] fw_cfg: remove inline from fw_cfg_read_blob() Marc-André Lureau
2018-02-15 21:33 ` [PATCH v15 08/11] fw_cfg: handle fw_cfg_read_blob() error Marc-André Lureau
2018-02-27 0:20 ` Michael S. Tsirkin
2018-02-28 11:49 ` Marc-André Lureau
2018-02-28 13:01 ` Gabriel Somlo
2018-02-28 15:32 ` Michael S. Tsirkin
2018-02-28 23:25 ` Gabriel Somlo
2018-02-28 23:58 ` Michael S. Tsirkin
2018-02-28 23:58 ` Michael S. Tsirkin
2018-03-01 0:49 ` Gabriel Somlo
2018-03-01 0:35 ` Gabriel Somlo
2018-02-15 21:33 ` [PATCH v15 09/11] fw_cfg: add DMA register Marc-André Lureau
2018-02-15 21:33 ` [PATCH v15 10/11] fw_cfg: write vmcoreinfo details Marc-André Lureau
2018-02-27 0:28 ` Michael S. Tsirkin
2018-02-28 12:22 ` Marc-André Lureau
2018-02-28 15:34 ` Michael S. Tsirkin
2018-02-15 21:33 ` [PATCH v15 11/11] RFC: fw_cfg: do DMA read operation Marc-André Lureau
2018-02-27 0:04 ` Michael S. Tsirkin
2018-02-28 12:27 ` Marc-André Lureau
2018-02-28 15:35 ` Michael S. Tsirkin
2018-02-28 15:41 ` Marc-André Lureau
2018-02-28 15:48 ` Michael S. Tsirkin
2018-02-28 16:00 ` Marc-André Lureau [this message]
2018-02-28 17:16 ` Michael S. Tsirkin
2018-02-28 17:17 ` Michael S. Tsirkin
2018-02-28 17:22 ` Marc-André Lureau
2018-02-27 0:29 ` [PATCH v15 00/11] fw_cfg: add DMA operations & etc/vmcoreinfo support Michael S. Tsirkin
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