From: Steven Rostedt <rostedt@goodmis.org>
To: Alexei Starovoitov <ast@plumgrid.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>,
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
Namhyung Kim <namhyung@kernel.org>,
Andi Kleen <andi@firstfloor.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 07/15] mm: Add ___GFP_NOTRACE
Date: Mon, 2 Mar 2015 13:43:29 -0500 [thread overview]
Message-ID: <20150302134329.623e8dce@gandalf.local.home> (raw)
In-Reply-To: <CAMEtUuzKLyemWbcKEiM6Lh_ADD=+UAs2Bt6H4XXfXePYxWSmWA@mail.gmail.com>
On Mon, 2 Mar 2015 10:12:32 -0800
Alexei Starovoitov <ast@plumgrid.com> wrote:
> I'm not sure what would be the meaning of hash map that has all
> elements pre-allocated...
> As I'm reading your cover letter, I agree, we need to find a way
> to call kmalloc_notrace-like from tracepoints.
> Not sure that patch 8 style of duplicating the functions is clean.
> Can we keep kmalloc/kfree as-is and do something like
> if (in_tracepoint()) check inside ftrace_raw_kmalloc* ?
I'm strongly against this. You should not be doing anything in a
tracepoint that you can't do from NMI context. And calling kmalloc
happens to be one of them.
Not to mention, kmalloc is a hot path, and tracing must not have any
impact on it (no extra if statements).
-- Steve
> so that kmalloc will be traced but calls to kmalloc from inside
> tracepoints will be automatically suppressed ?
next prev parent reply other threads:[~2015-03-02 18:43 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-02 16:00 [PATCH v2 00/15] tracing: 'hist' triggers Tom Zanussi
2015-03-02 16:00 ` [PATCH 01/15] tracing: Make ftrace_event_field checking functions available Tom Zanussi
2015-03-02 16:00 ` [PATCH 02/15] tracing: Add event record param to trigger_ops.func() Tom Zanussi
2015-03-02 16:00 ` [PATCH 03/15] tracing: Add get_syscall_name() Tom Zanussi
2015-03-02 16:00 ` [PATCH 04/15] bpf: Export bpf map functionality as trace_map_* Tom Zanussi
2015-03-02 16:00 ` [PATCH 05/15] bpf: Export a map-clearing function Tom Zanussi
2015-03-02 16:00 ` [PATCH 06/15] bpf: Add tracing_map client ops Tom Zanussi
2015-03-02 16:01 ` [PATCH 07/15] mm: Add ___GFP_NOTRACE Tom Zanussi
2015-03-02 16:37 ` Steven Rostedt
2015-03-02 16:46 ` Tom Zanussi
2015-03-02 17:58 ` Alexei Starovoitov
2015-03-02 18:03 ` Tom Zanussi
2015-03-02 18:12 ` Alexei Starovoitov
2015-03-02 18:25 ` Tom Zanussi
2015-03-02 18:43 ` Steven Rostedt [this message]
2015-03-02 16:01 ` [PATCH 08/15] tracing: Make kmem memory allocation tracepoints conditional Tom Zanussi
2015-03-02 16:01 ` [PATCH 09/15] tracing: Add kmalloc/kfree macros Tom Zanussi
2015-03-02 16:01 ` [PATCH 10/15] bpf: Make tracing_map use kmalloc/kfree_notrace() Tom Zanussi
2015-03-02 16:01 ` [PATCH 11/15] tracing: Add a per-event-trigger 'paused' field Tom Zanussi
2015-03-02 16:01 ` [PATCH 12/15] tracing: Add 'hist' event trigger command Tom Zanussi
2015-03-02 16:01 ` [PATCH 13/15] tracing: Add sorting to hist triggers Tom Zanussi
2015-03-02 16:01 ` [PATCH 14/15] tracing: Add enable_hist/disable_hist triggers Tom Zanussi
2015-03-02 16:01 ` [PATCH 15/15] tracing: Add 'hist' trigger Documentation Tom Zanussi
2015-03-03 2:25 ` [PATCH v2 00/15] tracing: 'hist' triggers Masami Hiramatsu
2015-03-03 14:47 ` Tom Zanussi
2015-03-02 18:40 [PATCH 07/15] mm: Add ___GFP_NOTRACE Alexei Starovoitov
2015-03-02 18:54 ` Tom Zanussi
2015-03-02 19:24 Alexei Starovoitov
2015-03-02 19:33 ` Steven Rostedt
2015-03-02 19:29 Alexei Starovoitov
2015-03-02 22:04 ` Tom Zanussi
2015-03-02 23:21 ` Alexei Starovoitov
2015-03-02 19:52 Alexei Starovoitov
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=20150302134329.623e8dce@gandalf.local.home \
--to=rostedt@goodmis.org \
--cc=andi@firstfloor.org \
--cc=ast@plumgrid.com \
--cc=linux-kernel@vger.kernel.org \
--cc=masami.hiramatsu.pt@hitachi.com \
--cc=namhyung@kernel.org \
--cc=tom.zanussi@linux.intel.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
all inboxes | Powered by JetHome®