From: Elena Afanasova <eafanasova@gmail.com>
To: David Gibson <david@gibson.dropbear.id.au>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: qemu-trivial@nongnu.org, Thomas Huth <thuth@redhat.com>,
qemu-ppc@nongnu.org, jasowang@redhat.com, qemu-devel@nongnu.org
Subject: Re: [PATCH] hw/net: move allocation to the heap due to very large stack frame
Date: Wed, 14 Oct 2020 07:15:47 -0700 [thread overview]
Message-ID: <96fa5d23ca57363e063b9b5006ad8f71e6b1b307.camel@gmail.com> (raw)
In-Reply-To: <20201013053250.GV71119@yekko.fritz.box>
On Tue, 2020-10-13 at 16:32 +1100, David Gibson wrote:
> On Mon, Oct 12, 2020 at 03:45:02PM +0200, Paolo Bonzini wrote:
> > On 12/10/20 12:44, Thomas Huth wrote:
> > > I think this is one of the tasks from:
> > >
> > >
> > > https://wiki.qemu.org/Contribute/BiteSizedTasks#Compiler-driven_cleanups
> > >
> > > It has been added by Paolo in 2016:
> > >
> > >
> > > https://wiki.qemu.org/index.php?title=Contribute/BiteSizedTasks&diff=5368&oldid=5367
> > >
> > > ... so maybe Paolo can comment on the size that has been chosen
> > > here...?
> >
> > I used 16K, mostly because it is a nice round number. 8k is too
> > small
> > due to PATH_MAX-sized variables. 16k seemed to be plenty and
> > triggered
> > in few-enough places that the cleanup is viable.
>
> Ok. Why are large stack frames bad in qemu?
>
I think that the main issue here is alloca() because it can lead to UB.
next prev parent reply other threads:[~2020-10-14 14:17 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-09 14:02 [PATCH] hw/net: move allocation to the heap due to very large stack frame Elena Afanasova
2020-10-09 14:14 ` Richard Henderson
2020-10-09 14:25 ` Philippe Mathieu-Daudé
2020-10-09 14:48 ` Greg Kurz
2020-10-09 14:55 ` Li Qiang
2020-10-10 6:07 ` David Gibson
2020-10-10 15:53 ` Elena Afanasova
2020-10-12 5:30 ` David Gibson
2020-10-12 10:44 ` Thomas Huth
2020-10-12 13:45 ` Paolo Bonzini
2020-10-13 5:32 ` David Gibson
2020-10-14 14:15 ` Elena Afanasova [this message]
2020-10-16 0:32 ` David Gibson
2020-10-11 2:23 ` Li Qiang
2020-10-12 5:28 ` David Gibson
2020-10-12 11:09 ` Philippe Mathieu-Daudé
2020-10-12 11:48 ` Philippe Mathieu-Daudé
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=96fa5d23ca57363e063b9b5006ad8f71e6b1b307.camel@gmail.com \
--to=eafanasova@gmail.com \
--cc=david@gibson.dropbear.id.au \
--cc=jasowang@redhat.com \
--cc=pbonzini@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=qemu-ppc@nongnu.org \
--cc=qemu-trivial@nongnu.org \
--cc=thuth@redhat.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).