From: Yafang Shao <laoar.shao@gmail.com>
To: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Kees Cook <keescook@chromium.org>,
Steven Rostedt <rostedt@goodmis.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>,
Petr Mladek <pmladek@suse.com>,
Peter Zijlstra <peterz@infradead.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Valentin Schneider <valentin.schneider@arm.com>,
Qiang Zhang <qiang.zhang@windriver.com>,
robdclark <robdclark@chromium.org>,
christian <christian@brauner.io>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Ingo Molnar <mingo@redhat.com>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
David Miller <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>, Martin Lau <kafai@fb.com>,
Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
john fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>,
dennis.dalessandro@cornelisnetworks.com,
mike.marciniszyn@cornelisnetworks.com, dledford@redhat.com,
jgg@ziepe.ca, linux-rdma@vger.kernel.org,
netdev <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
"linux-perf-use." <linux-perf-users@vger.kernel.org>,
linux-fsdevel@vger.kernel.org, Linux MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
kernel test robot <oliver.sang@intel.com>,
kbuild test robot <lkp@intel.com>
Subject: Re: [PATCH v7 00/11] extend task comm from 16 to 24
Date: Fri, 5 Nov 2021 14:34:58 +0800 [thread overview]
Message-ID: <CALOAHbDtoBEr8TuuUEMAnw3aeOf=S10Lh_eBCS=5Ty+JHgdj0Q@mail.gmail.com> (raw)
In-Reply-To: <YYM5R95a7jgB2TPO@qmqm.qmqm.pl>
On Thu, Nov 4, 2021 at 9:37 AM Michał Mirosław <mirq-linux@rere.qmqm.pl> wrote:
>
> On Mon, Nov 01, 2021 at 06:04:08AM +0000, Yafang Shao wrote:
> > There're many truncated kthreads in the kernel, which may make trouble
> > for the user, for example, the user can't get detailed device
> > information from the task comm.
> >
> > This patchset tries to improve this problem fundamentally by extending
> > the task comm size from 16 to 24, which is a very simple way.
> [...]
>
> Hi,
>
> I've tried something like this a few years back. My attempt got mostly
> lost in the mailing lists, but I'm still carrying the patches in my
> tree [1]. My target was userspace thread names, and it turned out more
> involved than I had time for.
>
> [1] https://rere.qmqm.pl/git/?p=linux;a=commit;h=2c3814268caf2b1fee6d1a0b61fd1730ce135d4a
> and its parents
>
Hi Michal,
Thanks for the information.
I have looked through your patches. It seems to contain six patches
now and can be divided into three parts per my understanding.
1. extend task comm len
This parts contains below 4 patches:
[prctl: prepare for bigger
TASK_COMM_LEN](https://rere.qmqm.pl/git/?p=linux;a=commit;h=cfd99db9cf911bb4d106889aeba1dfe89b6527d0)
[bluetooth: prepare for bigger
TASK_COMM_LEN](https://rere.qmqm.pl/git/?p=linux;a=commit;h=ba2805f5196865b81cc6fc938ea53af2c7c2c892)
[taskstats: prepare for bigger
TASK_COMM_LEN](https://rere.qmqm.pl/git/?p=linux;a=commit;h=4d29bfedc57b36607915a0171f4864ec504908ca)
[mm: make TASK_COMM_LEN
configurable](https://rere.qmqm.pl/git/?p=linux;a=commit;h=362acc35582445174589184c738c4d86ec7d174b)
What kind of userspace issues makes you extend the task comm length ?
Why not just use /proc/[pid]/cmdline ?
2. A fix
Below patch:
[procfs: signal /proc/PID/comm write
truncation](https://rere.qmqm.pl/git/?p=linux;a=commit;h=d72027388d4d95db5438a7a574e0a03ae4b5d6d7)
It seems this patch is incomplete ? I don't know what it means to do.
3. A feature provided for pthread_getname_np
Below patch:
[procfs: lseek(/proc/PID/comm, 0,
SEEK_END)](https://rere.qmqm.pl/git/?p=linux;a=commit;h=2c3814268caf2b1fee6d1a0b61fd1730ce135d4a)
It seems this patch is useful. With this patch the userspace can
directly get the TASK_COMM_LEN through the API.
--
Thanks
Yafang
next prev parent reply other threads:[~2021-11-05 6:35 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-01 6:04 [PATCH v7 00/11] extend task comm from 16 to 24 Yafang Shao
2021-11-01 6:04 ` [PATCH v7 01/11] fs/exec: make __set_task_comm always set a nul terminated string Yafang Shao
2021-11-01 6:04 ` [PATCH v7 02/11] fs/exec: make __get_task_comm always get " Yafang Shao
2021-11-01 6:04 ` [PATCH v7 03/11] sched.h: use __must_be_array instead of BUILD_BUG_ON in get_task_comm Yafang Shao
2021-11-01 6:04 ` [PATCH v7 04/11] drivers/infiniband: make setup_ctxt always get a nul terminated task comm Yafang Shao
2021-11-01 6:04 ` [PATCH v7 05/11] fs/binfmt_elf: make prpsinfo " Yafang Shao
2021-11-01 6:04 ` [PATCH v7 06/11] samples/bpf/test_overhead_kprobe_kern: make it adopt to task comm size change Yafang Shao
2021-11-01 6:04 ` [PATCH v7 07/11] tools/bpf/bpftool/skeleton: " Yafang Shao
2021-11-01 23:47 ` Andrii Nakryiko
2021-11-01 6:04 ` [PATCH v7 08/11] tools/perf/test: make perf test " Yafang Shao
2021-11-17 14:31 ` Arnaldo Carvalho de Melo
2021-11-18 14:18 ` Yafang Shao
2021-11-01 6:04 ` [PATCH v7 09/11] tools/testing/selftests/bpf: make it " Yafang Shao
2021-11-01 23:47 ` Andrii Nakryiko
2021-11-01 6:04 ` [PATCH v7 10/11] sched.h: extend task comm from 16 to 24 Yafang Shao
2021-11-01 6:04 ` [PATCH v7 11/11] kernel/kthread: show a warning if kthread's comm is truncated Yafang Shao
2021-11-01 12:44 ` [PATCH v7 00/11] extend task comm from 16 to 24 Matthew Wilcox
2021-11-01 13:12 ` Yafang Shao
2021-11-01 14:07 ` Petr Mladek
2021-11-01 14:34 ` Yafang Shao
2021-11-01 16:02 ` Petr Mladek
2021-11-01 16:06 ` Steven Rostedt
2021-11-02 1:09 ` Yafang Shao
2021-11-02 1:18 ` Steven Rostedt
2021-11-02 1:26 ` Yafang Shao
2021-11-02 7:56 ` Petr Mladek
2021-11-02 13:48 ` Yafang Shao
2021-11-02 9:26 ` David Hildenbrand
2021-11-04 1:37 ` Michał Mirosław
2021-11-05 6:34 ` Yafang Shao [this message]
2021-11-05 23:57 ` Michał Mirosław
2021-11-06 9:12 ` Yafang Shao
2021-11-06 11:29 ` Michał Mirosław
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='CALOAHbDtoBEr8TuuUEMAnw3aeOf=S10Lh_eBCS=5Ty+JHgdj0Q@mail.gmail.com' \
--to=laoar.shao@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=andrii@kernel.org \
--cc=arnaldo.melo@gmail.com \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=christian@brauner.io \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=dennis.dalessandro@cornelisnetworks.com \
--cc=dietmar.eggemann@arm.com \
--cc=dledford@redhat.com \
--cc=jgg@ziepe.ca \
--cc=john.fastabend@gmail.com \
--cc=juri.lelli@redhat.com \
--cc=kafai@fb.com \
--cc=keescook@chromium.org \
--cc=kpsingh@kernel.org \
--cc=kuba@kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-perf-users@vger.kernel.org \
--cc=linux-rdma@vger.kernel.org \
--cc=lkp@intel.com \
--cc=mathieu.desnoyers@efficios.com \
--cc=mike.marciniszyn@cornelisnetworks.com \
--cc=mingo@redhat.com \
--cc=mirq-linux@rere.qmqm.pl \
--cc=netdev@vger.kernel.org \
--cc=oliver.sang@intel.com \
--cc=peterz@infradead.org \
--cc=pmladek@suse.com \
--cc=qiang.zhang@windriver.com \
--cc=robdclark@chromium.org \
--cc=rostedt@goodmis.org \
--cc=songliubraving@fb.com \
--cc=valentin.schneider@arm.com \
--cc=vincent.guittot@linaro.org \
--cc=viro@zeniv.linux.org.uk \
--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).