From: Richard Henderson <richard.henderson@linaro.org>
To: Christian Ehrhardt <christian.ehrhardt@canonical.com>,
BALATON Zoltan <balaton@eik.bme.hu>
Cc: fam@euphon.net, "Daniel P. Berrange" <berrange@redhat.com>,
qemu-devel <qemu-devel@nongnu.org>,
f4bug@amsat.org, cota@braap.org, "Stefan Weil" <sw@weilnetz.de>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Alex Bennée" <alex.bennee@linaro.org>,
aurelien@aurel32.net
Subject: Re: [PATCH v1 4/5] util: add qemu_get_host_physmem utility function
Date: Fri, 17 Jul 2020 11:00:08 -0700 [thread overview]
Message-ID: <b565376b-a269-27c1-61c5-b010db963f9f@linaro.org> (raw)
In-Reply-To: <CAATJJ0+JV0PFcPBdr5CbMnQF2FZrSe7B0g0fGmzOobHhjOdfJg@mail.gmail.com>
On 7/17/20 7:24 AM, Christian Ehrhardt wrote:
> > +size_t qemu_get_host_physmem(void)
> > +{
> > +#ifdef _SC_PHYS_PAGES
> > + long pages = sysconf(_SC_PHYS_PAGES);
> > + if (pages > 0) {
> > + return pages * qemu_real_host_page_size;
>
> The Linux man page warns that this product may overflow so maybe you could
> return pages here.
>
>
> The caller might be even less aware of that than this function - so maybe
> better handle it here.
> How about handling overflows and cutting it to MiB before returning?
Indeed, the caller may be less aware, so we should handle it here. But I don't
think truncating to MiB helps at all, because again, the caller has to handle
overflow.
Better, I think, to saturate the result to ~(size_t)0 and leave it at that.
r~
next prev parent reply other threads:[~2020-07-17 18:01 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-17 10:51 [PATCH v1 0/5] candidate fixes for 5.1-rc1 (shippable, semihosting, OOM tcg) Alex Bennée
2020-07-17 10:51 ` [PATCH v1 1/5] shippable: add one more qemu to registry url Alex Bennée
2020-07-17 19:41 ` Philippe Mathieu-Daudé
2020-07-17 10:51 ` [PATCH v1 2/5] semihosting: defer connect_chardevs a little more to use serialx Alex Bennée
2020-07-17 17:41 ` Richard Henderson
2020-07-17 10:51 ` [PATCH v1 3/5] semihosting: don't send the trailing '\0' Alex Bennée
2020-07-17 17:47 ` Richard Henderson
2020-07-17 10:51 ` [PATCH v1 4/5] util: add qemu_get_host_physmem utility function Alex Bennée
2020-07-17 13:32 ` BALATON Zoltan
2020-07-17 14:24 ` Christian Ehrhardt
2020-07-17 18:00 ` Richard Henderson [this message]
2020-07-21 13:50 ` Alex Bennée
2020-07-17 18:05 ` Richard Henderson
2020-07-21 15:58 ` Alex Bennée
2020-07-17 10:51 ` [PATCH v1 5/5] accel/tcg: better handle memory constrained systems Alex Bennée
2020-07-17 14:23 ` Christian Ehrhardt
2020-07-17 14:39 ` Daniel P. Berrangé
2020-07-17 14:55 ` Alex Bennée
2020-07-17 15:00 ` Daniel P. Berrangé
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=b565376b-a269-27c1-61c5-b010db963f9f@linaro.org \
--to=richard.henderson@linaro.org \
--cc=alex.bennee@linaro.org \
--cc=aurelien@aurel32.net \
--cc=balaton@eik.bme.hu \
--cc=berrange@redhat.com \
--cc=christian.ehrhardt@canonical.com \
--cc=cota@braap.org \
--cc=f4bug@amsat.org \
--cc=fam@euphon.net \
--cc=pbonzini@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=sw@weilnetz.de \
/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).