From: Eduard Zingerman <eddyz87@gmail.com>
To: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc: dwarves@vger.kernel.org, bpf@vger.kernel.org, kernel-team@fb.com,
ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
yhs@fb.com, mykolal@fb.com
Subject: Re: [PATCH dwarves] pahole: avoid adding same struct structure to two rb trees
Date: Mon, 05 Jun 2023 17:39:19 +0300 [thread overview]
Message-ID: <2b4372428cd1e56de3b79791160cdd3afdc7df6a.camel@gmail.com> (raw)
In-Reply-To: <ZH3nalodXmup6pEF@kernel.org>
On Mon, 2023-06-05 at 10:47 -0300, Arnaldo Carvalho de Melo wrote:
> Em Fri, Jun 02, 2023 at 09:08:51PM +0300, Eduard Zingerman escreveu:
> > On Fri, 2023-06-02 at 15:04 -0300, Arnaldo Carvalho de Melo wrote:
> > > Em Fri, Jun 02, 2023 at 04:52:40PM +0300, Eduard Zingerman escreveu:
> > > > Right, you are correct.
> > > > The 'structures__tree = RB_ROOT' part is still necessary, though.
> > > > If you are ok with overall structure of the patch I can resend it w/o bzero().
>
> > > Humm, so basically this boils down to the following patch?
>
> > > +++ b/pahole.c
> > > @@ -674,7 +674,12 @@ static void print_ordered_classes(void)
> > > __print_ordered_classes(&structures__tree);
> > > } else {
> > > struct rb_root resorted = RB_ROOT;
> > > -
> > > +#ifdef DEBUG_CHECK_LEAKS
> > > + // We'll delete structures from structures__tree, since we're
> > > + // adding them to ther resorted list, better not keep
> > > + // references there.
> > > + structures__tree = RB_ROOT;
> > > +#endif
>
> > But __structures__delete iterates over structures__tree,
> > so it won't delete anything if code like this, right?
>
> > > resort_classes(&resorted, &structures__list);
> > > __print_ordered_classes(&resorted);
> > > }
>
> Yeah, I tried to be minimalistic, my version avoids the crash, but
> defeats the DEBUG_CHECK_LEAKS purpose :-\
>
> How about:
>
> diff --git a/pahole.c b/pahole.c
> index 6fc4ed6a721b97ab..e843999fde2a8a37 100644
> --- a/pahole.c
> +++ b/pahole.c
> @@ -673,10 +673,10 @@ static void print_ordered_classes(void)
> if (!need_resort) {
> __print_ordered_classes(&structures__tree);
> } else {
> - struct rb_root resorted = RB_ROOT;
> + structures__tree = RB_ROOT;
>
> - resort_classes(&resorted, &structures__list);
> - __print_ordered_classes(&resorted);
> + resort_classes(&structures__tree, &structures__list);
> + __print_ordered_classes(&structures__tree);
> }
> }
>
That would work, but I still think that there is no need to replicate call
to __print_ordered_classes, as long as the same list is passed as an argument,
e.g.:
@@ -670,14 +671,11 @@ static void resort_classes(struct rb_root *resorted, struct list_head *head)
static void print_ordered_classes(void)
{
- if (!need_resort) {
- __print_ordered_classes(&structures__tree);
- } else {
- struct rb_root resorted = RB_ROOT;
-
- resort_classes(&resorted, &structures__list);
- __print_ordered_classes(&resorted);
+ if (need_resort) {
+ structures__tree = RB_ROOT;
+ resort_classes(&structures__tree, &structures__list);
}
+ __print_ordered_classes(&structures__tree);
}
next prev parent reply other threads:[~2023-06-05 14:39 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-25 23:59 [PATCH dwarves] pahole: avoid adding same struct structure to two rb trees Eduard Zingerman
2023-06-02 13:42 ` Arnaldo Carvalho de Melo
2023-06-02 13:52 ` Eduard Zingerman
2023-06-02 18:04 ` Arnaldo Carvalho de Melo
2023-06-02 18:08 ` Eduard Zingerman
2023-06-05 13:47 ` Arnaldo Carvalho de Melo
2023-06-05 14:39 ` Eduard Zingerman [this message]
2023-06-05 18:54 ` Arnaldo Carvalho de Melo
2023-07-10 13:13 ` Arnaldo Carvalho de Melo
2023-07-10 13:15 ` Eduard Zingerman
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=2b4372428cd1e56de3b79791160cdd3afdc7df6a.camel@gmail.com \
--to=eddyz87@gmail.com \
--cc=andrii@kernel.org \
--cc=arnaldo.melo@gmail.com \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=dwarves@vger.kernel.org \
--cc=kernel-team@fb.com \
--cc=mykolal@fb.com \
--cc=yhs@fb.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).