From: Petr Mladek <pmladek@suse.com>
To: John Ogness <john.ogness@linutronix.de>
Cc: "Sergey Senozhatsky" <senozhatsky@chromium.org>,
"Steven Rostedt" <rostedt@goodmis.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
linux-kernel@vger.kernel.org,
"Paul E. McKenney" <paulmck@kernel.org>,
"Michael Ellerman" <mpe@ellerman.id.au>,
"Benjamin Herrenschmidt" <benh@kernel.crashing.org>,
"Paul Mackerras" <paulus@samba.org>,
"Eric Biederman" <ebiederm@xmission.com>,
"Nicholas Piggin" <npiggin@gmail.com>,
"Christophe Leroy" <christophe.leroy@csgroup.eu>,
"Cédric Le Goater" <clg@kaod.org>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Kees Cook" <keescook@chromium.org>,
"Tiezhu Yang" <yangtiezhu@loongson.cn>,
"Alexey Kardashevskiy" <aik@ozlabs.ru>,
"Yue Hu" <huyue2@yulong.com>,
linuxppc-dev@lists.ozlabs.org, kexec@lists.infradead.org,
"Russell King" <linux@armlinux.org.uk>,
"Ingo Molnar" <mingo@redhat.com>, "Marc Zyngier" <maz@kernel.org>,
"Valentin Schneider" <valentin.schneider@arm.com>,
"Geert Uytterhoeven" <geert@linux-m68k.org>,
"Mike Rapoport" <rppt@kernel.org>,
"Wolfram Sang (Renesas)" <wsa+renesas@sang-engineering.com>,
"Anshuman Khandual" <anshuman.khandual@arm.com>,
"Xiongwei Song" <sxwjean@gmail.com>,
"Frederic Weisbecker" <frederic@kernel.org>,
"Peter Zijlstra" <peterz@infradead.org>,
"Masahiro Yamada" <masahiroy@kernel.org>,
"Nathan Chancellor" <nathan@kernel.org>,
"Nick Desaulniers" <ndesaulniers@google.com>,
"Nick Terrell" <terrelln@fb.com>,
"Vipin Sharma" <vipinsh@google.com>,
"Rasmus Villemoes" <linux@rasmusvillemoes.dk>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"Vlastimil Babka" <vbabka@suse.cz>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH printk v4 0/6] printk: remove safe buffers
Date: Tue, 27 Jul 2021 09:26:54 +0200 [thread overview]
Message-ID: <YP+1PqaKTfZXHjmU@alley> (raw)
In-Reply-To: <20210715193359.25946-1-john.ogness@linutronix.de>
On Thu 2021-07-15 21:39:53, John Ogness wrote:
> Hi,
>
> Here is v4 of a series to remove the safe buffers. v3 can be
> found here [0]. The safe buffers are no longer needed because
> messages can be stored directly into the log buffer from any
> context.
>
> However, the safe buffers also provided a form of recursion
> protection. For that reason, explicit recursion protection is
> implemented for this series.
>
> The safe buffers also implicitly provided serialization
> between multiple CPUs executing in NMI context. This was
> particularly necessary for the nmi_backtrace() output. This
> serializiation is now preserved by using the printk cpulock.
>
> With the removal of the safe buffers, there is no need for
> extra NMI enter/exit tracking. So this is also removed
> (which includes removing the config option CONFIG_PRINTK_NMI).
>
> And finally, there are a few places in the kernel that need to
> specify code blocks where all printk calls are to be deferred
> printing. Previously the NMI tracking API was being (mis)used
> for this purpose. This series introduces an official and
> explicit interface for such cases. (Note that all deferred
> printing will be removed anyway, once printing kthreads are
> introduced.)
>
> John Ogness (6):
> lib/nmi_backtrace: explicitly serialize banner and regs
> printk: track/limit recursion
> printk: remove safe buffers
> printk: remove NMI tracking
> printk: convert @syslog_lock to mutex
> printk: syslog: close window between wait and read
The entire patchset has been committed into printk/linux.git,
branch rework/printk_safe-removal.
Note that I have updated the 4th patch as discussed, see
https://lore.kernel.org/r/20210721120026.y3dqno24ahw4sazy@pathway.suse.cz
https://lore.kernel.org/r/20210721130852.zrjnti6b3fwjgdzj@pathway.suse.cz
Best Regards,
Petr
WARNING: multiple messages have this Message-ID (diff)
From: Petr Mladek <pmladek@suse.com>
To: John Ogness <john.ogness@linutronix.de>
Cc: "Alexey Kardashevskiy" <aik@ozlabs.ru>,
"Rasmus Villemoes" <linux@rasmusvillemoes.dk>,
"Wolfram Sang (Renesas)" <wsa+renesas@sang-engineering.com>,
"Paul Mackerras" <paulus@samba.org>,
"Tiezhu Yang" <yangtiezhu@loongson.cn>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"Marc Zyngier" <maz@kernel.org>,
"Masahiro Yamada" <masahiroy@kernel.org>,
"Russell King" <linux@armlinux.org.uk>,
"Peter Zijlstra" <peterz@infradead.org>,
"Yue Hu" <huyue2@yulong.com>, "Ingo Molnar" <mingo@redhat.com>,
"Geert Uytterhoeven" <geert@linux-m68k.org>,
linux-arm-kernel@lists.infradead.org,
"Valentin Schneider" <valentin.schneider@arm.com>,
"Kees Cook" <keescook@chromium.org>,
"Paul E. McKenney" <paulmck@kernel.org>,
"Anshuman Khandual" <anshuman.khandual@arm.com>,
"Vipin Sharma" <vipinsh@google.com>,
"Frederic Weisbecker" <frederic@kernel.org>,
"Nicholas Piggin" <npiggin@gmail.com>,
"Nathan Chancellor" <nathan@kernel.org>,
"Nick Terrell" <terrelln@fb.com>,
"Steven Rostedt" <rostedt@goodmis.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Vlastimil Babka" <vbabka@suse.cz>,
"Nick Desaulniers" <ndesaulniers@google.com>,
"Xiongwei Song" <sxwjean@gmail.com>,
kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
"Sergey Senozhatsky" <senozhatsky@chromium.org>,
"Eric Biederman" <ebiederm@xmission.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
linuxppc-dev@lists.ozlabs.org, "Mike Rapoport" <rppt@kernel.org>,
"Cédric Le Goater" <clg@kaod.org>
Subject: Re: [PATCH printk v4 0/6] printk: remove safe buffers
Date: Tue, 27 Jul 2021 09:26:54 +0200 [thread overview]
Message-ID: <YP+1PqaKTfZXHjmU@alley> (raw)
In-Reply-To: <20210715193359.25946-1-john.ogness@linutronix.de>
On Thu 2021-07-15 21:39:53, John Ogness wrote:
> Hi,
>
> Here is v4 of a series to remove the safe buffers. v3 can be
> found here [0]. The safe buffers are no longer needed because
> messages can be stored directly into the log buffer from any
> context.
>
> However, the safe buffers also provided a form of recursion
> protection. For that reason, explicit recursion protection is
> implemented for this series.
>
> The safe buffers also implicitly provided serialization
> between multiple CPUs executing in NMI context. This was
> particularly necessary for the nmi_backtrace() output. This
> serializiation is now preserved by using the printk cpulock.
>
> With the removal of the safe buffers, there is no need for
> extra NMI enter/exit tracking. So this is also removed
> (which includes removing the config option CONFIG_PRINTK_NMI).
>
> And finally, there are a few places in the kernel that need to
> specify code blocks where all printk calls are to be deferred
> printing. Previously the NMI tracking API was being (mis)used
> for this purpose. This series introduces an official and
> explicit interface for such cases. (Note that all deferred
> printing will be removed anyway, once printing kthreads are
> introduced.)
>
> John Ogness (6):
> lib/nmi_backtrace: explicitly serialize banner and regs
> printk: track/limit recursion
> printk: remove safe buffers
> printk: remove NMI tracking
> printk: convert @syslog_lock to mutex
> printk: syslog: close window between wait and read
The entire patchset has been committed into printk/linux.git,
branch rework/printk_safe-removal.
Note that I have updated the 4th patch as discussed, see
https://lore.kernel.org/r/20210721120026.y3dqno24ahw4sazy@pathway.suse.cz
https://lore.kernel.org/r/20210721130852.zrjnti6b3fwjgdzj@pathway.suse.cz
Best Regards,
Petr
WARNING: multiple messages have this Message-ID (diff)
From: Petr Mladek <pmladek@suse.com>
To: John Ogness <john.ogness@linutronix.de>
Cc: "Sergey Senozhatsky" <senozhatsky@chromium.org>,
"Steven Rostedt" <rostedt@goodmis.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
linux-kernel@vger.kernel.org,
"Paul E. McKenney" <paulmck@kernel.org>,
"Michael Ellerman" <mpe@ellerman.id.au>,
"Benjamin Herrenschmidt" <benh@kernel.crashing.org>,
"Paul Mackerras" <paulus@samba.org>,
"Eric Biederman" <ebiederm@xmission.com>,
"Nicholas Piggin" <npiggin@gmail.com>,
"Christophe Leroy" <christophe.leroy@csgroup.eu>,
"Cédric Le Goater" <clg@kaod.org>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Kees Cook" <keescook@chromium.org>,
"Tiezhu Yang" <yangtiezhu@loongson.cn>,
"Alexey Kardashevskiy" <aik@ozlabs.ru>,
"Yue Hu" <huyue2@yulong.com>,
linuxppc-dev@lists.ozlabs.org, kexec@lists.infradead.org,
"Russell King" <linux@armlinux.org.uk>,
"Ingo Molnar" <mingo@redhat.com>, "Marc Zyngier" <maz@kernel.org>,
"Valentin Schneider" <valentin.schneider@arm.com>,
"Geert Uytterhoeven" <geert@linux-m68k.org>,
"Mike Rapoport" <rppt@kernel.org>,
"Wolfram Sang (Renesas)" <wsa+renesas@sang-engineering.com>,
"Anshuman Khandual" <anshuman.khandual@arm.com>,
"Xiongwei Song" <sxwjean@gmail.com>,
"Frederic Weisbecker" <frederic@kernel.org>,
"Peter Zijlstra" <peterz@infradead.org>,
"Masahiro Yamada" <masahiroy@kernel.org>,
"Nathan Chancellor" <nathan@kernel.org>,
"Nick Desaulniers" <ndesaulniers@google.com>,
"Nick Terrell" <terrelln@fb.com>,
"Vipin Sharma" <vipinsh@google.com>,
"Rasmus Villemoes" <linux@rasmusvillemoes.dk>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"Vlastimil Babka" <vbabka@suse.cz>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH printk v4 0/6] printk: remove safe buffers
Date: Tue, 27 Jul 2021 09:26:54 +0200 [thread overview]
Message-ID: <YP+1PqaKTfZXHjmU@alley> (raw)
In-Reply-To: <20210715193359.25946-1-john.ogness@linutronix.de>
On Thu 2021-07-15 21:39:53, John Ogness wrote:
> Hi,
>
> Here is v4 of a series to remove the safe buffers. v3 can be
> found here [0]. The safe buffers are no longer needed because
> messages can be stored directly into the log buffer from any
> context.
>
> However, the safe buffers also provided a form of recursion
> protection. For that reason, explicit recursion protection is
> implemented for this series.
>
> The safe buffers also implicitly provided serialization
> between multiple CPUs executing in NMI context. This was
> particularly necessary for the nmi_backtrace() output. This
> serializiation is now preserved by using the printk cpulock.
>
> With the removal of the safe buffers, there is no need for
> extra NMI enter/exit tracking. So this is also removed
> (which includes removing the config option CONFIG_PRINTK_NMI).
>
> And finally, there are a few places in the kernel that need to
> specify code blocks where all printk calls are to be deferred
> printing. Previously the NMI tracking API was being (mis)used
> for this purpose. This series introduces an official and
> explicit interface for such cases. (Note that all deferred
> printing will be removed anyway, once printing kthreads are
> introduced.)
>
> John Ogness (6):
> lib/nmi_backtrace: explicitly serialize banner and regs
> printk: track/limit recursion
> printk: remove safe buffers
> printk: remove NMI tracking
> printk: convert @syslog_lock to mutex
> printk: syslog: close window between wait and read
The entire patchset has been committed into printk/linux.git,
branch rework/printk_safe-removal.
Note that I have updated the 4th patch as discussed, see
https://lore.kernel.org/r/20210721120026.y3dqno24ahw4sazy@pathway.suse.cz
https://lore.kernel.org/r/20210721130852.zrjnti6b3fwjgdzj@pathway.suse.cz
Best Regards,
Petr
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Petr Mladek <pmladek@suse.com>
To: John Ogness <john.ogness@linutronix.de>
Cc: "Sergey Senozhatsky" <senozhatsky@chromium.org>,
"Steven Rostedt" <rostedt@goodmis.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
linux-kernel@vger.kernel.org,
"Paul E. McKenney" <paulmck@kernel.org>,
"Michael Ellerman" <mpe@ellerman.id.au>,
"Benjamin Herrenschmidt" <benh@kernel.crashing.org>,
"Paul Mackerras" <paulus@samba.org>,
"Eric Biederman" <ebiederm@xmission.com>,
"Nicholas Piggin" <npiggin@gmail.com>,
"Christophe Leroy" <christophe.leroy@csgroup.eu>,
"Cédric Le Goater" <clg@kaod.org>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Kees Cook" <keescook@chromium.org>,
"Tiezhu Yang" <yangtiezhu@loongson.cn>,
"Alexey Kardashevskiy" <aik@ozlabs.ru>,
"Yue Hu" <huyue2@yulong.com>,
linuxppc-dev@lists.ozlabs.org, kexec@lists.infradead.org,
"Russell King" <linux@armlinux.org.uk>,
"Ingo Molnar" <mingo@redhat.com>, "Marc Zyngier" <maz@kernel.org>,
"Valentin Schneider" <valentin.schneider@arm.com>,
"Geert Uytterhoeven" <geert@linux-m68k.org>,
"Mike Rapoport" <rppt@kernel.org>,
"Wolfram Sang (Renesas)" <wsa+renesas@sang-engineering.com>,
"Anshuman Khandual" <anshuman.khandual@arm.com>,
"Xiongwei Song" <sxwjean@gmail.com>,
"Frederic Weisbecker" <frederic@kernel.org>,
"Peter Zijlstra" <peterz@infradead.org>,
"Masahiro Yamada" <masahiroy@kernel.org>,
"Nathan Chancellor" <nathan@kernel.org>,
"Nick Desaulniers" <ndesaulniers@google.com>,
"Nick Terrell" <terrelln@fb.com>,
"Vipin Sharma" <vipinsh@google.com>,
"Rasmus Villemoes" <linux@rasmusvillemoes.dk>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"Vlastimil Babka" <vbabka@suse.cz>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH printk v4 0/6] printk: remove safe buffers
Date: Tue, 27 Jul 2021 09:26:54 +0200 [thread overview]
Message-ID: <YP+1PqaKTfZXHjmU@alley> (raw)
In-Reply-To: <20210715193359.25946-1-john.ogness@linutronix.de>
On Thu 2021-07-15 21:39:53, John Ogness wrote:
> Hi,
>
> Here is v4 of a series to remove the safe buffers. v3 can be
> found here [0]. The safe buffers are no longer needed because
> messages can be stored directly into the log buffer from any
> context.
>
> However, the safe buffers also provided a form of recursion
> protection. For that reason, explicit recursion protection is
> implemented for this series.
>
> The safe buffers also implicitly provided serialization
> between multiple CPUs executing in NMI context. This was
> particularly necessary for the nmi_backtrace() output. This
> serializiation is now preserved by using the printk cpulock.
>
> With the removal of the safe buffers, there is no need for
> extra NMI enter/exit tracking. So this is also removed
> (which includes removing the config option CONFIG_PRINTK_NMI).
>
> And finally, there are a few places in the kernel that need to
> specify code blocks where all printk calls are to be deferred
> printing. Previously the NMI tracking API was being (mis)used
> for this purpose. This series introduces an official and
> explicit interface for such cases. (Note that all deferred
> printing will be removed anyway, once printing kthreads are
> introduced.)
>
> John Ogness (6):
> lib/nmi_backtrace: explicitly serialize banner and regs
> printk: track/limit recursion
> printk: remove safe buffers
> printk: remove NMI tracking
> printk: convert @syslog_lock to mutex
> printk: syslog: close window between wait and read
The entire patchset has been committed into printk/linux.git,
branch rework/printk_safe-removal.
Note that I have updated the 4th patch as discussed, see
https://lore.kernel.org/r/20210721120026.y3dqno24ahw4sazy@pathway.suse.cz
https://lore.kernel.org/r/20210721130852.zrjnti6b3fwjgdzj@pathway.suse.cz
Best Regards,
Petr
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2021-07-27 7:26 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-15 19:33 [PATCH printk v4 0/6] printk: remove safe buffers John Ogness
2021-07-15 19:33 ` John Ogness
2021-07-15 19:33 ` John Ogness
2021-07-15 19:33 ` John Ogness
2021-07-15 19:33 ` [PATCH printk v4 1/6] lib/nmi_backtrace: explicitly serialize banner and regs John Ogness
2021-07-15 19:33 ` [PATCH printk v4 2/6] printk: track/limit recursion John Ogness
2021-07-15 19:33 ` [PATCH printk v4 3/6] printk: remove safe buffers John Ogness
2021-07-15 19:33 ` John Ogness
2021-07-15 19:33 ` John Ogness
2021-07-21 11:25 ` Petr Mladek
2021-07-21 11:25 ` Petr Mladek
2021-07-21 11:25 ` Petr Mladek
2021-09-02 16:48 ` Geert Uytterhoeven
2021-09-02 16:48 ` Geert Uytterhoeven
2021-09-02 16:48 ` Geert Uytterhoeven
2021-07-15 19:33 ` [PATCH printk v4 4/6] printk: remove NMI tracking John Ogness
2021-07-15 19:33 ` John Ogness
2021-07-15 19:33 ` John Ogness
2021-07-21 12:00 ` Petr Mladek
2021-07-21 12:00 ` Petr Mladek
2021-07-21 12:00 ` Petr Mladek
2021-07-21 12:46 ` John Ogness
2021-07-21 12:46 ` John Ogness
2021-07-21 12:46 ` John Ogness
2021-07-21 13:08 ` Petr Mladek
2021-07-21 13:08 ` Petr Mladek
2021-07-21 13:08 ` Petr Mladek
2021-07-21 13:23 ` John Ogness
2021-07-21 13:23 ` John Ogness
2021-07-21 13:23 ` John Ogness
2021-07-15 19:33 ` [PATCH printk v4 5/6] printk: convert @syslog_lock to mutex John Ogness
2021-07-21 12:21 ` Petr Mladek
2021-07-15 19:33 ` [PATCH printk v4 6/6] printk: syslog: close window between wait and read John Ogness
2021-07-21 12:43 ` Petr Mladek
2021-07-27 7:26 ` Petr Mladek [this message]
2021-07-27 7:26 ` [PATCH printk v4 0/6] printk: remove safe buffers Petr Mladek
2021-07-27 7:26 ` Petr Mladek
2021-07-27 7:26 ` Petr Mladek
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