linux-next.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
	"H. Peter Anvin" <hpa@zytor.com>, Len Brown <lenb@kernel.org>,
	linux-next@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: linux-next: build failure after merge of the tip tree
Date: Thu, 16 Jan 2014 13:19:55 +0100	[thread overview]
Message-ID: <20140116121955.GQ31570@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20140116145829.5e4fcab103b1c5c77501ee77@canb.auug.org.au>

On Thu, Jan 16, 2014 at 02:58:29PM +1100, Stephen Rothwell wrote:
> Hi all,
> 
> After merging the tip tree, today's linux-next build (x86_64 allmodconfig)
> failed like this:
> 
> arch/x86/kernel/process.c: In function 'mwait_idle':
> /scratch/sfr/next/arch/x86/kernel/process.c:434:3: error: implicit declaration of function '__monitor' [-Werror=implicit-function-declaration]
>    __monitor((void *)&current_thread_info()->flags, 0, 0);
>    ^
> arch/x86/kernel/process.c:437:4: error: implicit declaration of function '__sti_mwait' [-Werror=implicit-function-declaration]
>     __sti_mwait(0, 0);
>     ^
> 
> Caused by commit 16824255394f ("x86, acpi, idle: Restructure the mwait
> idle routines") interacting with commit 7760518cce95 ("x86 idle: restore
> mwait_idle()") from the idle tree.
> 
> I am not sure how to fix this so I just reverted the idle tree commit for
> now (since it reverted cleanly). Please let me know if there is a better
> solution.

I think the below ought to work

---
 arch/x86/kernel/process.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 3fb8d95ab8b5..220df9b2f22a 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -28,6 +28,7 @@
 #include <asm/fpu-internal.h>
 #include <asm/debugreg.h>
 #include <asm/nmi.h>
+#include <asm/mwait.h>
 
 /*
  * per-CPU TSS segments. Threads are completely 'soft' on Linux,
@@ -398,6 +399,37 @@ static void amd_e400_idle(void)
 		default_idle();
 }
 
+/*
+ * Intel Core2 and older machines prefer MWAIT over HALT for C1.
+ * We can't rely on cpuidle installing MWAIT, because it will not load
+ * on systems that support only C1 -- so the boot default must be MWAIT.
+ *  
+ * Some AMD machines are the opposite, they depend on using HALT.
+ *
+ * So for default C1, which is used during boot until cpuidle loads,
+ * use MWAIT-C1 on Intel HW that has it, else use HALT.
+ */
+static int prefer_mwait_c1_over_halt(const struct cpuinfo_x86 *c)
+{
+	if (c->x86_vendor != X86_VENDOR_INTEL)
+		return 0;
+
+	if (!cpu_has(c, X86_FEATURE_MWAIT))
+		return 0;
+
+	return 1;
+}
+
+/*
+ * MONITOR/MWAIT with no hints, used for default default C1 state.
+ * This invokes MWAIT with interrutps enabled and no flags,
+ * which is backwards compatible with the original MWAIT implementation.
+ */
+static void mwait_idle(void)
+{
+	mwait_idle_with_hints(0, 0);
+}
+
 void select_idle_routine(const struct cpuinfo_x86 *c)
 {
 #ifdef CONFIG_SMP
@@ -411,6 +443,9 @@ void select_idle_routine(const struct cpuinfo_x86 *c)
 		/* E400: APIC timer interrupt does not wake up CPU from C1e */
 		pr_info("using AMD E400 aware idle routine\n");
 		x86_idle = amd_e400_idle;
+	} else if (prefer_mwait_c1_over_halt(c)) {
+		pr_info("using mwait in idle threads\n");
+		x86_idle = mwait_idle;
 	} else
 		x86_idle = default_idle;
 }

  reply	other threads:[~2014-01-16 12:20 UTC|newest]

Thread overview: 357+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-01-16  3:58 linux-next: build failure after merge of the tip tree Stephen Rothwell
2014-01-16 12:19 ` Peter Zijlstra [this message]
2014-01-16 20:46   ` Stephen Rothwell
2014-01-16 22:25     ` Peter Zijlstra
2014-01-16 22:34       ` Stephen Rothwell
2014-01-16 22:51         ` H. Peter Anvin
2014-01-17  3:45           ` Stephen Rothwell
2014-01-18  9:46             ` Mike Galbraith
2014-01-18 12:44               ` Peter Zijlstra
2014-01-18 14:06                 ` Sabrina Dubroca
2014-01-18 15:21                 ` Mike Galbraith
2014-01-18 19:14                   ` H. Peter Anvin
2014-01-18 21:54                     ` Peter Zijlstra
2014-01-20  3:51               ` Stephen Rothwell
2014-01-20  8:42                 ` Sedat Dilek
2014-01-20  8:46                   ` Sedat Dilek
2014-01-20 13:10                     ` Stephen Rothwell
2014-01-20 15:28                       ` Sedat Dilek
2014-01-20  9:17                   ` Mike Galbraith
2014-01-20  9:25                     ` Sedat Dilek
2014-01-20  9:48                       ` Mike Galbraith
2014-01-20  4:45     ` Len Brown
2014-01-20  8:26       ` Peter Zijlstra
2014-01-20  8:56         ` H. Peter Anvin
2014-01-20  9:16           ` Peter Zijlstra
2014-01-20  9:23             ` H. Peter Anvin
2014-01-20  9:29               ` Ingo Molnar
2014-01-20 21:39                 ` Len Brown
2014-01-20 21:51                   ` Peter Zijlstra
2014-01-21  3:26                     ` Mike Galbraith
2014-01-21 10:47                     ` Ingo Molnar
2014-01-20  9:55               ` Peter Zijlstra
2014-01-20 11:00                 ` H. Peter Anvin
2014-01-20 11:05                   ` Peter Zijlstra
2014-01-16 20:56   ` H. Peter Anvin
2014-01-20  1:00 ` Len Brown
2014-01-20  1:07   ` H. Peter Anvin
2014-01-20  8:30   ` Peter Zijlstra
2014-01-20 10:13     ` Peter Zijlstra
2014-01-20 10:19       ` H. Peter Anvin
2014-01-20 11:06         ` Peter Zijlstra
  -- strict thread matches above, loose matches on Subject: below --
2024-01-29  1:22 Stephen Rothwell
2024-01-29  8:14 ` Bartosz Golaszewski
2023-08-15  5:29 Stephen Rothwell
2023-08-15 15:54 ` Edgecombe, Rick P
2023-06-20  4:53 Stephen Rothwell
2023-04-21 16:03 broonie
2023-04-19 18:21 linux-next: Build " broonie
2023-04-19 18:50 ` Borislav Petkov
2022-12-13  1:40 linux-next: build " Stephen Rothwell
2022-12-15 16:34 ` Ricardo Neri
2022-12-05  1:15 Stephen Rothwell
2022-12-02  0:26 Stephen Rothwell
2022-12-02  1:33 ` Benjamin Gray
2022-12-02  9:37 ` Michael Ellerman
2022-03-15  3:06 Stephen Rothwell
2022-03-15  5:23 ` Stephen Rothwell
2022-03-15  5:37   ` Stephen Rothwell
2022-03-15  8:42     ` Stephen Rothwell
2022-03-15  9:22     ` Peter Zijlstra
2022-03-15 10:41       ` Stephen Rothwell
2021-12-13 17:08 broonie
2021-11-26  3:52 Stephen Rothwell
2021-11-26 10:01 ` Arnd Bergmann
2021-12-01 22:05   ` Stephen Rothwell
2021-12-01 22:17     ` Thomas Gleixner
2021-12-01 22:19       ` Thomas Gleixner
2021-12-01 22:31         ` Stephen Rothwell
2021-10-25  4:11 Stephen Rothwell
2021-10-25  7:42 ` Borislav Petkov
2021-10-25  7:58   ` Stephen Rothwell
2021-10-25  8:37     ` Borislav Petkov
2021-10-28  5:10 ` Stephen Rothwell
2021-10-28  8:17   ` Borislav Petkov
2021-10-18  6:23 Stephen Rothwell
2021-10-18  6:45 ` Qi Zheng
2021-10-06  2:58 Stephen Rothwell
2021-10-06  9:31 ` Borislav Petkov
2021-10-06  9:54   ` Stephen Rothwell
2021-10-06  9:56     ` Borislav Petkov
2021-06-28  3:36 Stephen Rothwell
2021-06-28  5:42 ` Ingo Molnar
2021-05-13  2:05 Stephen Rothwell
2021-05-13 10:51 ` Ingo Molnar
2021-05-13 11:11   ` H. Peter Anvin
2021-03-22  3:37 Stephen Rothwell
2021-03-22  9:00 ` Borislav Petkov
2021-03-26  8:57   ` Sedat Dilek
2021-03-26 13:11     ` Borislav Petkov
2021-03-27 11:50       ` Sedat Dilek
2021-03-27 21:26         ` Stephen Rothwell
2021-03-23  8:34 ` Sedat Dilek
2021-03-17  4:08 Stephen Rothwell
2021-03-17 10:54 ` Borislav Petkov
2021-03-17 16:22   ` Ian Rogers
2021-03-17 18:02     ` Borislav Petkov
2021-03-17 18:49       ` Stephen Rothwell
2021-03-17 19:18         ` Borislav Petkov
2021-03-17 20:04           ` Ingo Molnar
2021-03-17 21:54             ` Stephen Rothwell
2021-03-02 23:38 Stephen Rothwell
2021-03-03  9:44 ` Peter Zijlstra
2021-03-03 11:29   ` Stephen Rothwell
2021-01-14  4:11 Stephen Rothwell
2021-01-14 10:07 ` Borislav Petkov
2020-11-27  4:10 Stephen Rothwell
2020-11-27 10:11 ` Ingo Molnar
2020-11-09  3:34 Stephen Rothwell
2020-10-09  4:28 Stephen Rothwell
2020-10-09  6:47 ` Vasily Gorbik
2020-09-08  9:12 Stephen Rothwell
2020-09-08 10:57 ` peterz
2020-09-03  2:35 Stephen Rothwell
2020-09-03  3:51 ` Ingo Molnar
2020-09-03  4:44   ` Stephen Rothwell
2020-08-03  5:45 Stephen Rothwell
2020-07-31  5:53 Stephen Rothwell
2020-07-31  9:57 ` Ingo Molnar
2020-07-31 10:02   ` Stephen Rothwell
2020-06-22  1:37 Stephen Rothwell
2020-06-30  2:54 ` Stephen Rothwell
2020-07-07  2:33   ` Stephen Rothwell
2020-07-14  3:50     ` Stephen Rothwell
2020-07-20  5:37       ` Stephen Rothwell
2020-06-21  6:33 Stephen Rothwell
2020-06-21 10:53 ` Borislav Petkov
2020-06-22  1:38   ` Stephen Rothwell
2020-05-21 17:31 Stephen Rothwell
2020-05-21 17:35 ` Will Deacon
2020-05-22  7:17   ` Stephen Rothwell
2020-05-22  7:49     ` Stephen Rothwell
2020-05-23  0:12       ` Paul E. McKenney
2020-05-23  6:46         ` Borislav Petkov
2020-05-23  9:54           ` Thomas Gleixner
2020-05-23 15:06             ` Paul E. McKenney
2020-05-23 19:05               ` Thomas Gleixner
2020-05-23 21:23                 ` Paul E. McKenney
2020-05-25  0:37                   ` Paul E. McKenney
2020-05-25  8:20                     ` Marco Elver
2020-05-25 16:13                       ` Paul E. McKenney
2020-05-15  6:00 Stephen Rothwell
2020-03-30  3:35 Stephen Rothwell
2020-03-30  3:53 ` H.J. Lu
2020-03-30  4:08   ` Stephen Rothwell
2020-03-30  7:48     ` Borislav Petkov
2020-03-30  8:04       ` Michael Ellerman
2020-03-30  8:16         ` Borislav Petkov
2020-03-30 11:34           ` H.J. Lu
2020-03-26  2:52 Stephen Rothwell
2020-03-26 10:59 ` Qais Yousef
2020-04-01  1:14 ` Stephen Rothwell
2020-04-03  8:15   ` Baolin Wang
2020-04-03  9:50     ` Sebastian Reichel
2019-11-21  3:54 Stephen Rothwell
2019-11-21  8:36 ` Peter Zijlstra
2019-11-21 18:37 ` Alex Deucher
2019-11-18  3:11 Stephen Rothwell
2019-11-18  9:49 ` Jiri Slaby
2019-11-18 12:49 ` Borislav Petkov
2019-10-21  2:13 Stephen Rothwell
2019-10-21  5:51 ` Ingo Molnar
2019-10-21  6:37   ` Stephen Rothwell
2019-10-10  2:14 Stephen Rothwell
2019-10-10  8:02 ` Ingo Molnar
2019-10-10 11:23   ` Stephen Rothwell
2019-10-10 13:44     ` Daniel Vetter
2019-11-06  2:53 ` Stephen Rothwell
2019-11-27 23:39   ` Stephen Rothwell
2019-08-29  6:20 Stephen Rothwell
2019-08-29  7:46 ` Peter Zijlstra
2019-08-29 12:24   ` Thomas Gleixner
2019-08-29 13:04     ` Peter Zijlstra
2019-08-08  4:48 Stephen Rothwell
2019-08-01  3:38 Stephen Rothwell
2019-07-09  6:54 Stephen Rothwell
2019-07-10  0:01 ` Stephen Rothwell
2019-07-10 18:21   ` Ilya Dryomov
2019-07-10 21:38     ` Stephen Rothwell
2019-07-02  5:33 Stephen Rothwell
2019-07-02 10:28 ` David Sterba
2019-07-02 12:57   ` Stephen Rothwell
2019-07-08  6:50   ` Stephen Rothwell
2019-06-25  6:04 Stephen Rothwell
2019-06-25  6:23 ` Kalle Valo
2019-06-25  6:26   ` Thomas Gleixner
2019-06-25  6:36   ` Stephen Rothwell
2019-06-25  6:51     ` Kalle Valo
2019-06-25  6:56     ` Thomas Gleixner
2019-06-25  7:47       ` Kalle Valo
2019-07-09  0:09 ` Stephen Rothwell
2019-07-09  3:46 ` Stephen Rothwell
2018-11-06  0:43 Stephen Rothwell
2018-08-08 23:24 Stephen Rothwell
2018-08-09  9:41 ` Joerg Roedel
2018-04-03  5:41 Stephen Rothwell
2018-04-03  9:30 ` Peter Zijlstra
2018-04-03 12:39 ` David Howells
2018-04-03 12:42   ` Peter Zijlstra
2018-04-03 12:41 ` David Howells
2017-11-08  2:47 Stephen Rothwell
2017-11-08  3:01 ` Josh Poimboeuf
2017-11-08  7:35   ` Stephen Rothwell
2017-11-08  9:18   ` Ingo Molnar
2017-11-08 12:14     ` Stephen Rothwell
2017-11-09  6:18       ` Ingo Molnar
2017-11-08 13:17     ` Josh Poimboeuf
2017-11-09  3:03     ` Stephen Rothwell
2017-11-01 10:51 Stephen Rothwell
2017-11-01 14:32 ` Kees Cook
2017-06-28  3:43 Stephen Rothwell
2017-06-28  4:00 ` jeffy
2017-06-28  4:24   ` Stephen Rothwell
2017-07-03  3:01 ` Stephen Rothwell
2017-05-02  3:17 Stephen Rothwell
2017-04-24  3:32 Stephen Rothwell
2017-04-24  5:31 ` Ingo Molnar
2017-04-05  3:36 Stephen Rothwell
2017-04-05  7:24 ` Mikko Perttunen
2016-12-07  1:37 Stephen Rothwell
2016-12-07  7:45 ` Ingo Molnar
2016-12-07  8:12   ` Jiri Olsa
2016-12-07 14:49     ` Arnaldo Carvalho de Melo
2016-12-07 18:56       ` Ingo Molnar
2016-12-07 20:32         ` Stephen Rothwell
2016-11-17  3:22 Stephen Rothwell
2016-09-29  3:20 Stephen Rothwell
2016-09-29 12:25 ` Rafael J. Wysocki
2016-09-29 15:54   ` Chen, Yu C
2016-09-29 20:50     ` Rafael J. Wysocki
2016-09-21  3:23 Stephen Rothwell
2016-09-21  6:44 ` Viresh Kumar
2016-07-18  8:29 Stephen Rothwell
2016-07-18 14:27 ` Paul Gortmaker
2016-07-18  5:15 Stephen Rothwell
2016-04-18  3:03 Stephen Rothwell
2016-04-14  2:14 Stephen Rothwell
2016-04-14 12:35 ` Arnaldo Carvalho de Melo
2016-04-14 12:55   ` Michael Ellerman
2016-04-14 15:08     ` Arnaldo Carvalho de Melo
2016-04-15 21:15 ` Arnaldo Carvalho de Melo
2016-04-15 21:28   ` Arnaldo Carvalho de Melo
2016-04-17 12:12     ` Jiri Olsa
2016-04-17 13:04       ` Jiri Olsa
2016-04-18 13:24         ` Arnaldo Carvalho de Melo
2016-04-18 13:28           ` Jiri Olsa
2016-03-01  1:29 Stephen Rothwell
2016-03-01  7:07 ` Ingo Molnar
2016-03-01  7:28   ` Sedat Dilek
2016-03-01  7:39     ` H. Peter Anvin
2016-03-01  8:41       ` Sedat Dilek
2016-03-01  9:45       ` Ingo Molnar
2016-03-01  9:40   ` Stephen Rothwell
2015-09-16  1:30 Stephen Rothwell
2015-09-16  4:53 ` David Miller
2015-09-16  0:12 Stephen Rothwell
2015-09-16  6:16 ` Jiri Olsa
2015-09-16  6:38   ` Jiri Olsa
2015-09-16  7:30     ` Stephen Rothwell
2015-09-16 14:17       ` Arnaldo Carvalho de Melo
2015-09-17  0:34   ` Stephen Rothwell
2015-09-30  2:56     ` Stephen Rothwell
2015-09-30  6:08       ` Jiri Olsa
2015-09-30  6:17         ` Stephen Rothwell
2015-07-28  5:33 Stephen Rothwell
2015-07-28 16:34 ` Luis R. Rodriguez
2015-07-28 18:17   ` Luis R. Rodriguez
2015-07-28  2:43 Stephen Rothwell
2015-07-28  8:41 ` Sudeep Holla
2015-07-28  9:43   ` Gregory CLEMENT
2015-07-15  1:01 Stephen Rothwell
2015-07-08  0:56 Stephen Rothwell
2015-07-08  9:40 ` Thomas Gleixner
2015-06-12 10:51 Michael Ellerman
     [not found] ` <BY1PR0701MB17063C25D627AF725A9E0D46FEBB0@BY1PR0701MB1706.namprd07.prod.outlook.com>
2015-06-12 21:22   ` David Miller
2015-06-12 21:25     ` Chickles, Derek
2015-06-09  7:15 Stephen Rothwell
2015-04-07  7:18 Stephen Rothwell
2015-04-07  8:48 ` Ingo Molnar
2015-04-07  8:56   ` Daniel Borkmann
2015-04-07  9:05     ` Stephen Rothwell
2015-04-07 11:13       ` Daniel Borkmann
2015-04-07 16:18         ` Alexei Starovoitov
2015-04-07 19:54           ` Daniel Borkmann
2015-04-08  5:03             ` Stephen Rothwell
2015-04-15  1:25               ` Stephen Rothwell
2015-04-07  8:53 ` Peter Zijlstra
2015-03-30  6:13 Stephen Rothwell
2015-03-30  7:15 ` Russell King - ARM Linux
2015-03-30  8:08   ` Stephen Rothwell
2015-03-30 14:57     ` Nathan Lynch
2015-03-30 15:08       ` Russell King - ARM Linux
2015-03-30 15:24         ` Nathan Lynch
2015-04-13 23:34         ` Stephen Rothwell
2014-07-25  4:45 Stephen Rothwell
2014-07-29 23:56 ` Stephen Rothwell
2014-07-30  3:10   ` John Stultz
2014-06-04  6:05 Stephen Rothwell
2014-06-04 10:49 ` Thomas Gleixner
2014-06-04 14:46   ` Linus Torvalds
2014-06-04 16:23   ` Olof Johansson
2014-06-04 20:02     ` Thomas Gleixner
2014-05-23  7:14 Stephen Rothwell
2014-05-29  1:38 ` Stephen Rothwell
2014-04-24  3:51 Stephen Rothwell
2014-02-12  2:41 Stephen Rothwell
2014-02-12  4:48 ` Preeti U Murthy
2014-02-11  3:00 Stephen Rothwell
2014-01-14  3:26 Stephen Rothwell
2014-01-14 14:14 ` Peter Zijlstra
2014-01-14 19:06   ` Mikulas Patocka
2014-01-14 20:05     ` Peter Zijlstra
2014-01-14 21:43       ` Mikulas Patocka
2014-01-14 22:03         ` Rafael J. Wysocki
2014-01-14 21:52           ` Mikulas Patocka
2014-01-14 22:18             ` Rafael J. Wysocki
2014-01-16 12:14         ` Peter Zijlstra
2013-10-28  9:24 Stephen Rothwell
2013-10-28 10:18 ` Thierry Reding
2013-10-28 10:26   ` Ingo Molnar
2013-10-29  6:00     ` Stephen Rothwell
2013-04-29  5:45 Stephen Rothwell
2013-02-14  2:30 Stephen Rothwell
2013-02-21  2:04 ` Stephen Rothwell
2013-02-02  5:04 Stephen Rothwell
2012-08-16  3:12 Stephen Rothwell
2012-08-16 19:46 ` Paul E. McKenney
2012-08-17  0:56   ` Stephen Rothwell
2012-08-17 11:50     ` Paul E. McKenney
2012-08-20  4:54       ` Stephen Rothwell
2012-08-20 15:09         ` Paul E. McKenney
2012-03-08  4:21 Stephen Rothwell
2012-03-08 18:00 ` Greg KH
2012-03-20 22:00   ` Stephen Rothwell
2012-03-20 22:32     ` Greg KH
2012-03-21  9:53     ` Alan Cox
2012-03-21 12:19     ` Alan Cox
2012-03-21 12:29       ` Stephen Rothwell
2012-02-24  3:47 Stephen Rothwell
2012-02-24  3:34 Stephen Rothwell
2011-10-05  6:25 Stephen Rothwell
2011-10-05  8:46 ` Peter Zijlstra
2011-10-11  6:15   ` Stephen Rothwell
2011-06-27  4:22 Stephen Rothwell
2011-06-28 10:55 ` Stijn Devriendt
2011-04-01  2:00 Stephen Rothwell
2011-01-31  4:42 Stephen Rothwell
2011-02-17  3:47 ` Stephen Rothwell
2011-02-17 13:18   ` Michal Marek
2011-02-17 15:02     ` Michal Marek
2011-02-17 17:11       ` Ingo Molnar
2011-02-17 22:47       ` Stephen Rothwell
2011-02-18  3:54         ` Stephen Rothwell
2010-10-19  5:13 Stephen Rothwell
2010-07-29  3:04 Stephen Rothwell
2010-05-10  4:49 Stephen Rothwell
2010-05-10  5:09 ` H. Peter Anvin
2010-03-12  4:00 Stephen Rothwell

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=20140116121955.GQ31570@twins.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=hpa@zytor.com \
    --cc=lenb@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-next@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=sfr@canb.auug.org.au \
    --cc=tglx@linutronix.de \
    /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).