Dwarves Archive on lore.kernel.org
 help / color / Atom feed
From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: Hao Luo <haoluo@google.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
	Arnaldo Carvalho de Melo <acme@redhat.com>,
	Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>,
	Andrii Nakryiko <andrii.nakryiko@gmail.com>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Martin KaFai Lau <kafai@fb.com>,
	dwarves@vger.kernel.org, Yonghong Song <yhs@fb.com>,
	bpf <bpf@vger.kernel.org>
Subject: Re: [PATCH v1] btf_encoder: Handle DW_TAG_variable that has DW_AT_specification
Date: Thu, 1 Oct 2020 14:07:23 -0700
Message-ID: <CAADnVQKJc45UhkRj_cjJLvW=crXhN-BpUN0rM4XK_KbLTioAow@mail.gmail.com> (raw)
In-Reply-To: <CA+khW7iVd3zUa0iwLuf=SwE3TtnNPB1ZGkUvWPfVt7JpJPcX5w@mail.gmail.com>

On Thu, Oct 1, 2020 at 1:57 PM Hao Luo <haoluo@google.com> wrote:
>
> Arnaldo, thanks for the update. In that case, I think on the kernel
> side I need to skip encoding percpu vars for this pahole release, and
> re-enable for the next pahole release. (assuming the flag for opt-out
> is in this release). Alexei, do you have any better idea?

I'm not following. Let's get this fix landed in pahole and
release new 1.18 with it.
The opt-out flag is orthogonal. I can be done in 1.19 or whenever.
With your kernel patches the kernel will reject percpu vars when pahole
is too old, because they will not be found in vmlinux btf,
so I don't see any compatibility issues.
There is no need to bump the required min version of pahole in
scripts/link-vmlinux.sh.
It can stay as v1.16. We only need clean verifier message that percpu BTF
is not found and the kernel needs to be rebuilt with pahole 1.18.

  reply index

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20200825004523.1353133-1-haoluo@google.com>
     [not found] ` <20200826131143.GF1059382@kernel.org>
     [not found]   ` <CA+khW7jf7Z=sMC1u5eyn6XOZDTFJaNjV-D0ogvQSyUGSKjC3LQ@mail.gmail.com>
     [not found]     ` <DEC4CC81-88CE-4476-A631-2BBB6E922F5C@gmail.com>
2020-09-30  6:52       ` Hao Luo
2020-10-01 15:47         ` Alexei Starovoitov
2020-10-01 18:24           ` Arnaldo Carvalho de Melo
2020-10-01 18:40             ` Hao Luo
2020-10-01 20:27               ` Arnaldo Carvalho de Melo
2020-10-01 20:57                 ` Hao Luo
2020-10-01 21:07                   ` Alexei Starovoitov [this message]
2020-10-01 21:31                     ` Hao Luo

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='CAADnVQKJc45UhkRj_cjJLvW=crXhN-BpUN0rM4XK_KbLTioAow@mail.gmail.com' \
    --to=alexei.starovoitov@gmail.com \
    --cc=acme@kernel.org \
    --cc=acme@redhat.com \
    --cc=andrii.nakryiko@gmail.com \
    --cc=arnaldo.melo@gmail.com \
    --cc=bpf@vger.kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=dwarves@vger.kernel.org \
    --cc=haoluo@google.com \
    --cc=kafai@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

Dwarves Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/dwarves/0 dwarves/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 dwarves dwarves/ https://lore.kernel.org/dwarves \
		dwarves@vger.kernel.org
	public-inbox-index dwarves

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.dwarves


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git