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From: Rusty Russell <rusty@rustcorp.com.au>
To: Amit Shah <amit.shah@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
	"Linus Walleij" <linus.walleij@linaro.org>,
	linux-kernel@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	"Masami Hiramatsu" <masami.hiramatsu.pt@hitachi.com>,
	"Sjur Brændeland" <sjur.brandeland@stericsson.com>
Subject: Re: [PATCHv7 2/4] virtio_console: Use kmalloc instead of kzalloc
Date: Tue, 23 Oct 2012 12:06:34 +1030	[thread overview]
Message-ID: <87d30ahsv1.fsf@rustcorp.com.au> (raw)
In-Reply-To: <1350287856-5284-3-git-send-email-sjur.brandeland@stericsson.com>

sjur.brandeland@stericsson.com writes:

> From: Sjur Brændeland <sjur.brandeland@stericsson.com>
>
> Avoid the more cpu expensive kzalloc when allocating buffers.
> Originally kzalloc was intended for isolating the guest from
> the host by not sending random guest data to the host. But device
> isolation is not yet in place so kzalloc is not really needed.
>
> Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>

This looks fine to me.  This is *why* the device gives us the length
which was written; we can trust that, even if we can't trust the
writer of data.

(In theory: noone has implemented such a system, yet).

Applied.
Rusty.

> diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
> index c36b2f6..301d17e 100644
> --- a/drivers/char/virtio_console.c
> +++ b/drivers/char/virtio_console.c
> @@ -349,7 +349,7 @@ static struct port_buffer *alloc_buf(size_t buf_size)
>  	buf = kmalloc(sizeof(*buf), GFP_KERNEL);
>  	if (!buf)
>  		goto fail;
> -	buf->buf = kzalloc(buf_size, GFP_KERNEL);
> +	buf->buf = kmalloc(buf_size, GFP_KERNEL);
>  	if (!buf->buf)
>  		goto free_buf;
>  	buf->len = 0;
> -- 
> 1.7.5.4
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WARNING: multiple messages have this Message-ID (diff)
From: Rusty Russell <rusty@rustcorp.com.au>
To: sjur.brandeland@stericsson.com, Amit Shah <amit.shah@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
	"Linus Walleij" <linus.walleij@linaro.org>,
	"Masami Hiramatsu" <masami.hiramatsu.pt@hitachi.com>,
	"Ohad Ben-Cohen" <ohad@wizery.com>,
	linux-kernel@vger.kernel.org,
	virtualization@lists.linux-foundation.org, sjurbren@gmail.com,
	"Sjur Brændeland" <sjur.brandeland@stericsson.com>
Subject: Re: [PATCHv7 2/4] virtio_console: Use kmalloc instead of kzalloc
Date: Tue, 23 Oct 2012 12:06:34 +1030	[thread overview]
Message-ID: <87d30ahsv1.fsf@rustcorp.com.au> (raw)
In-Reply-To: <1350287856-5284-3-git-send-email-sjur.brandeland@stericsson.com>

sjur.brandeland@stericsson.com writes:

> From: Sjur Brændeland <sjur.brandeland@stericsson.com>
>
> Avoid the more cpu expensive kzalloc when allocating buffers.
> Originally kzalloc was intended for isolating the guest from
> the host by not sending random guest data to the host. But device
> isolation is not yet in place so kzalloc is not really needed.
>
> Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>

This looks fine to me.  This is *why* the device gives us the length
which was written; we can trust that, even if we can't trust the
writer of data.

(In theory: noone has implemented such a system, yet).

Applied.
Rusty.

> diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
> index c36b2f6..301d17e 100644
> --- a/drivers/char/virtio_console.c
> +++ b/drivers/char/virtio_console.c
> @@ -349,7 +349,7 @@ static struct port_buffer *alloc_buf(size_t buf_size)
>  	buf = kmalloc(sizeof(*buf), GFP_KERNEL);
>  	if (!buf)
>  		goto fail;
> -	buf->buf = kzalloc(buf_size, GFP_KERNEL);
> +	buf->buf = kmalloc(buf_size, GFP_KERNEL);
>  	if (!buf->buf)
>  		goto free_buf;
>  	buf->len = 0;
> -- 
> 1.7.5.4

  reply	other threads:[~2012-10-23  1:36 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-15  7:57 [PATCHv7 0/4] virtio_console: Add rproc_serial driver sjur.brandeland
2012-10-15  7:57 ` sjur.brandeland
2012-10-15  7:57 ` [PATCHv7 1/4] virtio_console: Free buffer if splice fails sjur.brandeland
2012-10-15  7:57 ` sjur.brandeland
2012-10-23  0:12   ` Rusty Russell
2012-10-23  0:12     ` Rusty Russell
2012-10-15  7:57 ` [PATCHv7 2/4] virtio_console: Use kmalloc instead of kzalloc sjur.brandeland
2012-10-15  7:57   ` sjur.brandeland
2012-10-23  1:36   ` Rusty Russell [this message]
2012-10-23  1:36     ` Rusty Russell
2012-10-15  7:57 ` [PATCHv7 3/4] virtio_console: Merge struct buffer_token into struct port_buffer sjur.brandeland
2012-10-15  7:57   ` sjur.brandeland
2012-10-23  0:19   ` Rusty Russell
2012-10-23  0:19     ` Rusty Russell
2012-10-15  7:57 ` [PATCHv7 4/4] virtio_console: Add support for remoteproc serial sjur.brandeland
2012-10-15  7:57   ` sjur.brandeland
2012-10-23  1:47   ` Rusty Russell
2012-10-28 21:58     ` Sjur Brændeland
2012-10-28 21:58       ` Sjur Brændeland
2012-11-01  7:39     ` Amit Shah
2012-11-01  7:39     ` Amit Shah
2012-11-01 23:22       ` Rusty Russell
2012-11-01 23:22         ` Rusty Russell
2012-11-02 10:20         ` Amit Shah
2012-11-02 10:20           ` Amit Shah
2012-11-02 10:44           ` Sjur BRENDELAND
2012-11-02 10:44             ` Sjur BRENDELAND
2012-11-07 13:43           ` [PATCH resend] virtio_console: Free buffers from out-queue upon close sjur.brandeland
2012-11-07 13:43             ` sjur.brandeland
2012-11-07 23:58             ` Rusty Russell
2012-11-07 23:58             ` Rusty Russell
2012-11-08  8:59               ` Amit Shah
2012-11-08  8:59                 ` Amit Shah
2012-11-08  9:25                 ` Sjur Brændeland
2012-11-08  9:25                   ` Sjur Brændeland
2012-11-07 14:22           ` sjur.brandeland
2012-11-07 14:22             ` sjur.brandeland
2012-10-23  1:47   ` [PATCHv7 4/4] virtio_console: Add support for remoteproc serial Rusty Russell
2012-10-22 13:00 ` [PATCHv7 0/4] virtio_console: Add rproc_serial driver Amit Shah
2012-10-22 13:00   ` Amit Shah

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