From: Josh Poimboeuf <jpoimboe@redhat.com>
To: David Laight <David.Laight@ACULAB.COM>
Cc: 'Shile Zhang' <shile.zhang@linux.alibaba.com>,
Peter Zijlstra <peterz@infradead.org>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
Michal Marek <michal.lkml@markovi.net>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"x86@kernel.org" <x86@kernel.org>,
"H . Peter Anvin" <hpa@zytor.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-kbuild@vger.kernel.org" <linux-kbuild@vger.kernel.org>
Subject: Re: [RFC PATCH v3 7/7] x86/unwind/orc: remove run-time ORC unwind tables sort
Date: Fri, 15 Nov 2019 11:46:49 -0600 [thread overview]
Message-ID: <20191115174649.ldif5o7xqo5ntxeo@treble> (raw)
In-Reply-To: <893d3caf85cd4ed0921fab84cfe28cad@AcuMS.aculab.com>
On Fri, Nov 15, 2019 at 04:51:24PM +0000, David Laight wrote:
> From: Shile Zhang
> > Sent: 15 November 2019 06:48
> ...
> > arch/x86/kernel/unwind_orc.c | 8 +++++---
> > 1 file changed, 5 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c
> > index 332ae6530fa8..280da6fa9922 100644
> > --- a/arch/x86/kernel/unwind_orc.c
> > +++ b/arch/x86/kernel/unwind_orc.c
> > @@ -273,9 +273,11 @@ void __init unwind_init(void)
> > return;
> > }
> >
> > - /* Sort the .orc_unwind and .orc_unwind_ip tables: */
> > - sort(__start_orc_unwind_ip, num_entries, sizeof(int), orc_sort_cmp,
> > - orc_sort_swap);
> > + /*
> > + * Note, orc_unwind and orc_unwind_ip tables has been sorted in
> > + * vmlinux link phase by sorttable tool at build time.
> > + * Its ready for binary search now.
> > + */
>
> How fast is sort() if the table is sorted?
> Relying on the kernel sources and build scripts always being in sync seems dangerous.
> Probably better to leave the sort in for a release of two.
This patch comes after the build script changes, so they'd be in sync.
What would the concern be?
--
Josh
next prev parent reply other threads:[~2019-11-15 17:47 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-15 6:47 [RFC PATCH v3 0/7] Speed booting by sorting ORC unwind tables at build time Shile Zhang
2019-11-15 6:47 ` [RFC PATCH v3 1/7] scripts/sortextable: Rewrite error/success handling Shile Zhang
2019-11-15 6:47 ` [RFC PATCH v3 2/7] scripts/sortextable: kernel coding style formating Shile Zhang
2019-11-15 6:47 ` [RFC PATCH v3 3/7] scripts/sortextable: Remove dead code Shile Zhang
2019-11-15 6:47 ` [RFC PATCH v3 4/7] scripts/sortextable: refactor do_func() function Shile Zhang
2019-11-15 6:47 ` [RFC PATCH v3 5/7] scripts/sorttable: rename sortextable to sorttable Shile Zhang
2019-11-15 6:47 ` [RFC PATCH v3 6/7] scripts/sorttable: Add ORC unwind tables sort concurrently Shile Zhang
2019-11-15 9:07 ` Peter Zijlstra
2019-11-15 9:43 ` Shile Zhang
2019-11-15 10:33 ` Peter Zijlstra
2019-11-15 17:24 ` Andy Lutomirski
2019-11-18 11:43 ` Shile Zhang
2019-11-15 9:19 ` Peter Zijlstra
2019-11-15 9:45 ` Shile Zhang
2019-11-15 6:47 ` [RFC PATCH v3 7/7] x86/unwind/orc: remove run-time ORC unwind tables sort Shile Zhang
2019-11-15 16:51 ` David Laight
2019-11-15 17:46 ` Josh Poimboeuf [this message]
2019-11-18 10:05 ` David Laight
2019-11-18 10:50 ` Shile Zhang
2019-11-18 14:41 ` Josh Poimboeuf
2019-11-15 7:25 ` [RFC PATCH v3 0/7] Speed booting by sorting ORC unwind tables at build time Ingo Molnar
2019-11-15 8:24 ` Shile Zhang
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