Mirror of the gdb-patches mailing list
 help / color / mirror / Atom feed
From: Michael Snyder <msnyder@vmware.com>
To: Hui Zhu <teawater@gmail.com>
Cc: "gdb-patches@sourceware.org" <gdb-patches@sourceware.org>
Subject: Re: [RFA] record.c - save some memory in record log.
Date: Sun, 18 Oct 2009 03:56:00 -0000	[thread overview]
Message-ID: <4ADA908C.1030808@vmware.com> (raw)
In-Reply-To: <daef60380910171850m1de9d507v7d85b9360ad5526a@mail.gmail.com>

Hui Zhu wrote:
> Thanks Michael, This patch is very cool.
> 
> +struct record_reg_entry
> +{
> +  unsigned short num;
> +  unsigned short len;
> +  union
> +  {
> +    gdb_byte *ptr;
> +    gdb_byte buf[2 * sizeof (gdb_byte *)];
> 
> Why this part use "2 * sizeof (gdb_byte *)"?

Oh, no strong reason.  I just noticed that mem_entry is larger
than reg_entry, and since it is used in a union, that space is
otherwise going to waste.

I do not assume that a target general register is the same size
as a host pointer -- only that the larger we make this buf, the
less likely that we have to use malloc.

> 
> +    rec->u.reg.u.ptr = (gdb_byte *) xmalloc (MAX_REGISTER_SIZE);
> I suggest change MAX_REGISTER_SIZE to rec->u.reg.len.

Ah, good idea, thanks.  I'll make that change.

Any other comments?


  reply	other threads:[~2009-10-18  3:56 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-15 17:59 Michael Snyder
2009-10-15 19:17 ` Joel Brobecker
2009-10-18  1:53   ` Hui Zhu
2009-10-18 16:10     ` Joel Brobecker
2009-10-18 16:14       ` Michael Snyder
2009-10-18  1:50 ` Hui Zhu
2009-10-18  3:56   ` Michael Snyder [this message]
2009-10-18  4:46     ` Hui Zhu
2009-10-18 16:11       ` Michael Snyder

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=4ADA908C.1030808@vmware.com \
    --to=msnyder@vmware.com \
    --cc=gdb-patches@sourceware.org \
    --cc=teawater@gmail.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