From: Steven Rostedt <rostedt@goodmis.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
linux-kbuild@vger.kernel.org, bpf <bpf@vger.kernel.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Masahiro Yamada <masahiroy@kernel.org>,
Nathan Chancellor <nathan@kernel.org>,
Nicolas Schier <nicolas@fjasle.eu>,
Zheng Yejian <zhengyejian1@huawei.com>,
Martin Kelly <martin.kelly@crowdstrike.com>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
Josh Poimboeuf <jpoimboe@redhat.com>
Subject: Re: [PATCH 14/14] scripts/sorttable: ftrace: Do not add weak functions to available_filter_functions
Date: Thu, 2 Jan 2025 15:30:16 -0500 [thread overview]
Message-ID: <20250102153016.7fc5e443@gandalf.local.home> (raw)
In-Reply-To: <20250102202404.GD7274@noisy.programming.kicks-ass.net>
On Thu, 2 Jan 2025 21:24:04 +0100
Peter Zijlstra <peterz@infradead.org> wrote:
> It is not. If kallsyms is fixed, you can use that to tell which
> fentry/mcount sites are 'invalid'.
I can't use kallsyms for valid tests at boot up. Even with a binary search,
it's still rather slow. The ftrace table is created at early boot, even
before scheduling (it's needed before you can enable boot time function
tracing), so any slow down in creating that table slows down the boot, and
people will notice.
-- Steve
next prev parent reply other threads:[~2025-01-02 20:29 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-02 18:58 [PATCH 00/14] scripts/sorttable: ftrace: Remove place holders for weak functions in available_filter_functions Steven Rostedt
2025-01-02 18:58 ` [PATCH 01/14] scripts/sorttable: Remove unused macro defines Steven Rostedt
2025-01-02 18:58 ` [PATCH 02/14] scripts/sorttable: Remove unused write functions Steven Rostedt
2025-01-02 18:58 ` [PATCH 03/14] scripts/sorttable: Remove unneeded Elf_Rel Steven Rostedt
2025-01-02 18:58 ` [PATCH 04/14] scripts/sorttable: Have the ORC code use the _r() functions to read Steven Rostedt
2025-01-02 18:58 ` [PATCH 05/14] scripts/sorttable: Make compare_extable() into two functions Steven Rostedt
2025-01-02 18:58 ` [PATCH 06/14] scripts/sorttable: Convert Elf_Ehdr to union Steven Rostedt
2025-01-02 18:58 ` [PATCH 07/14] scripts/sorttable: Replace Elf_Shdr Macro with a union Steven Rostedt
2025-01-02 18:58 ` [PATCH 08/14] scripts/sorttable: Convert Elf_Sym MACRO over to " Steven Rostedt
2025-01-02 18:58 ` [PATCH 09/14] scripts/sorttable: Add helper functions for Elf_Ehdr Steven Rostedt
2025-01-02 18:58 ` [PATCH 10/14] scripts/sorttable: Add helper functions for Elf_Shdr Steven Rostedt
2025-01-02 18:58 ` [PATCH 11/14] scripts/sorttable: Add helper functions for Elf_Sym Steven Rostedt
2025-01-02 18:58 ` [PATCH 12/14] scripts/sorttable: Use uint64_t for mcount sorting Steven Rostedt
2025-01-02 18:58 ` [PATCH 13/14] scripts/sorttable: Move code from sorttable.h into sorttable.c Steven Rostedt
2025-01-02 18:58 ` [PATCH 14/14] scripts/sorttable: ftrace: Do not add weak functions to available_filter_functions Steven Rostedt
2025-01-02 19:48 ` Peter Zijlstra
2025-01-02 19:55 ` Steven Rostedt
2025-01-02 20:03 ` Steven Rostedt
2025-01-02 20:32 ` Peter Zijlstra
2025-01-02 20:41 ` Steven Rostedt
2025-01-02 20:48 ` Peter Zijlstra
2025-01-02 20:53 ` Steven Rostedt
2025-01-02 20:24 ` Peter Zijlstra
2025-01-02 20:30 ` Steven Rostedt [this message]
2025-01-02 20:36 ` Peter Zijlstra
2025-01-02 20:45 ` Steven Rostedt
2025-01-03 11:10 ` Jiri Olsa
2025-01-03 11:41 ` Peter Zijlstra
2025-01-03 12:14 ` Steven Rostedt
2025-01-03 18:06 ` Jiri Olsa
2025-01-02 19:24 ` [PATCH 00/14] scripts/sorttable: ftrace: Remove place holders for weak functions in available_filter_functions Steven Rostedt
2025-01-02 19:30 ` Linus Torvalds
2025-01-02 19:45 ` Steven Rostedt
2025-01-02 19:47 ` Steven Rostedt
2025-01-02 21:44 ` Steven Rostedt
2025-01-02 22:14 ` Steven Rostedt
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