From: Richard Henderson <richard.henderson@linaro.org>
To: Wei Yang <richardw.yang@linux.intel.com>,
pbonzini@redhat.com, ehabkost@redhat.com, imammedo@redhat.com,
kwolf@redhat.com, mreitz@redhat.com, stefanha@redhat.com,
fam@euphon.net, den@openvz.org, marcandre.lureau@redhat.com,
kraxel@redhat.com, mst@redhat.com, cohuck@redhat.com,
pasic@linux.ibm.com, borntraeger@de.ibm.com,
mark.cave-ayland@ilande.co.uk, david@gibson.dropbear.id.au,
yuval.shaia@oracle.com, marcel.apfelbaum@gmail.com,
alex.williamson@redhat.com, quintela@redhat.com,
dgilbert@redhat.com, armbru@redhat.com, sw@weilnetz.de
Cc: qemu-s390x@nongnu.org, qemu-ppc@nongnu.org,
qemu-devel@nongnu.org, qemu-block@nongnu.org
Subject: Re: [PATCH 1/2] cpu: use ROUND_UP() to define xxx_PAGE_ALIGN
Date: Sun, 13 Oct 2019 11:56:35 -0400 [thread overview]
Message-ID: <41a924dc-f91b-c03b-4f82-570757105798@linaro.org> (raw)
In-Reply-To: <20191013021145.16011-2-richardw.yang@linux.intel.com>
On 10/12/19 10:11 PM, Wei Yang wrote:
> Use ROUND_UP() to define, which is a little bit easy to read.
>
> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
> ---
> include/exec/cpu-all.h | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h
> index ad9ab85eb3..255bb186ac 100644
> --- a/include/exec/cpu-all.h
> +++ b/include/exec/cpu-all.h
> @@ -220,7 +220,7 @@ extern int target_page_bits;
>
> #define TARGET_PAGE_SIZE (1 << TARGET_PAGE_BITS)
> #define TARGET_PAGE_MASK ~(TARGET_PAGE_SIZE - 1)
> -#define TARGET_PAGE_ALIGN(addr) (((addr) + TARGET_PAGE_SIZE - 1) & TARGET_PAGE_MASK)
> +#define TARGET_PAGE_ALIGN(addr) ROUND_UP((addr), TARGET_PAGE_SIZE)
>
> /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even
> * when intptr_t is 32-bit and we are aligning a long long.
> @@ -228,9 +228,8 @@ extern int target_page_bits;
> extern uintptr_t qemu_host_page_size;
> extern intptr_t qemu_host_page_mask;
>
> -#define HOST_PAGE_ALIGN(addr) (((addr) + qemu_host_page_size - 1) & qemu_host_page_mask)
> -#define REAL_HOST_PAGE_ALIGN(addr) (((addr) + qemu_real_host_page_size - 1) & \
> - qemu_real_host_page_mask)
> +#define HOST_PAGE_ALIGN(addr) ROUND_UP((addr), qemu_host_page_size)
> +#define REAL_HOST_PAGE_ALIGN(addr) ROUND_UP((addr), qemu_real_host_page_size)
No, please.
(1) The compiler does not know that qemu_*host_page_size is a power of 2, and
will generate a real division at runtime. The same is true for
TARGET_PAGE_SIZE when TARGET_PAGE_BITS_VARY.
(2) The first hunk conflicts with an in-flight patch of mine:
https://lists.gnu.org/archive/html/qemu-devel/2019-09/msg04526.html
r~
next prev parent reply other threads:[~2019-10-13 15:57 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-13 2:11 [PATCH 0/2] cleanup on page size Wei Yang
2019-10-13 2:11 ` [PATCH 1/2] cpu: use ROUND_UP() to define xxx_PAGE_ALIGN Wei Yang
2019-10-13 6:34 ` Michael S. Tsirkin
2019-10-13 9:27 ` David Gibson
2019-10-13 15:56 ` Richard Henderson [this message]
2019-10-13 23:36 ` David Gibson
2019-10-14 1:01 ` Wei Yang
2019-10-14 2:38 ` Richard Henderson
2019-10-14 3:19 ` Wei Yang
2019-10-14 16:25 ` Juan Quintela
2019-10-13 2:11 ` [PATCH 2/2] core: replace getpagesize() with qemu_real_host_page_size Wei Yang
2019-10-13 6:35 ` Michael S. Tsirkin
2019-10-13 9:28 ` David Gibson
2019-10-16 1:25 ` Wei Yang
2019-10-13 16:03 ` Richard Henderson
2019-10-14 9:15 ` Dr. David Alan Gilbert
2019-10-14 21:36 ` Wei Yang
2019-10-14 23:12 ` Richard Henderson
2019-10-15 11:45 ` Yuval Shaia
2019-10-16 1:07 ` Wei Yang
2019-10-23 9:19 ` Paolo Bonzini
2019-10-13 6:36 ` [PATCH 0/2] cleanup on page size Michael S. Tsirkin
2019-10-14 21:59 ` Wei Yang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=41a924dc-f91b-c03b-4f82-570757105798@linaro.org \
--to=richard.henderson@linaro.org \
--cc=alex.williamson@redhat.com \
--cc=armbru@redhat.com \
--cc=borntraeger@de.ibm.com \
--cc=cohuck@redhat.com \
--cc=david@gibson.dropbear.id.au \
--cc=den@openvz.org \
--cc=dgilbert@redhat.com \
--cc=ehabkost@redhat.com \
--cc=fam@euphon.net \
--cc=imammedo@redhat.com \
--cc=kraxel@redhat.com \
--cc=kwolf@redhat.com \
--cc=marcandre.lureau@redhat.com \
--cc=marcel.apfelbaum@gmail.com \
--cc=mark.cave-ayland@ilande.co.uk \
--cc=mreitz@redhat.com \
--cc=mst@redhat.com \
--cc=pasic@linux.ibm.com \
--cc=pbonzini@redhat.com \
--cc=qemu-block@nongnu.org \
--cc=qemu-devel@nongnu.org \
--cc=qemu-ppc@nongnu.org \
--cc=qemu-s390x@nongnu.org \
--cc=quintela@redhat.com \
--cc=richardw.yang@linux.intel.com \
--cc=stefanha@redhat.com \
--cc=sw@weilnetz.de \
--cc=yuval.shaia@oracle.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).