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From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jslaby@suse.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH 00/15] hvc and powerpc opal console latency reduction
Date: Tue,  1 May 2018 00:55:43 +1000	[thread overview]
Message-ID: <20180430145558.4308-1-npiggin@gmail.com> (raw)

I'm seeing scattered reports of hard lockups triggering in the OPAL
console code. I haven't got a full latency trace -- they are difficult
to reproduce and sometimes just show up in dmesg of a bug report when
the system is having other issues. But it does seem like there are
some improvements that can be made to the hvc console and powerpc
opal driver.

I'm not sure how this series should be merged yet, but we can cross
that if/when it comes. Possibly all can go via the tty tree with
acks from powerpc maintainers.

Comments appreciated.

Thanks,
Nick

--
Nicholas Piggin (15):
  powerpc/powernv: opal_put_chars partial write fix
  powerpc/powernv: Fix OPAL console driver OPAL_BUSY loops
  powerpc/powernv: opal-kmsg standardise OPAL_BUSY handling
  powerpc/powernv: opal-kmsg use flush fallback from console code
  powerpc/powernv: Implement and use opal_flush_console
  powerpc/powernv: Remove OPALv1 support from opal console driver
  powerpc/powernv: move opal console flushing to udbg
  powerpc/powernv: implement opal_put_chars_atomic
  tty: hvc: remove unexplained "just in case" spin delay
  tty: hvc: use mutex instead of spinlock for hvc_structs lock
  tty: hvc: hvc_poll break hv read loop
  tty: hvc: hvc_poll may sleep
  tty: hvc: hvc_write may sleep
  tty: hvc: introduce the hv_ops.flush operation for hvc drivers
  powerpc/powernv: provide a console flush operation for opal hvc driver

 arch/powerpc/include/asm/opal.h            |   3 +
 arch/powerpc/platforms/powernv/opal-kmsg.c |  30 +---
 arch/powerpc/platforms/powernv/opal.c      | 176 +++++++++++++------
 drivers/tty/hvc/hvc_console.c              | 194 +++++++++++++--------
 drivers/tty/hvc/hvc_console.h              |   1 +
 drivers/tty/hvc/hvc_opal.c                 |  33 ++--
 6 files changed, 276 insertions(+), 161 deletions(-)

-- 
2.17.0

             reply	other threads:[~2018-04-30 14:55 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-30 14:55 Nicholas Piggin [this message]
2018-04-30 14:55 ` [PATCH 01/15] powerpc/powernv: opal_put_chars partial write fix Nicholas Piggin
2018-07-24 13:59   ` [01/15] " Michael Ellerman
2018-04-30 14:55 ` [PATCH 02/15] powerpc/powernv: Fix OPAL console driver OPAL_BUSY loops Nicholas Piggin
2018-04-30 14:55 ` [PATCH 03/15] powerpc/powernv: opal-kmsg standardise OPAL_BUSY handling Nicholas Piggin
2018-04-30 14:55 ` [PATCH 04/15] powerpc/powernv: opal-kmsg use flush fallback from console code Nicholas Piggin
2018-05-04  5:16   ` Michael Ellerman
2018-05-04  5:37     ` Nicholas Piggin
2018-05-07 10:36       ` Michael Ellerman
2018-05-08  3:40         ` Nicholas Piggin
2018-04-30 14:55 ` [PATCH 05/15] powerpc/powernv: Implement and use opal_flush_console Nicholas Piggin
2018-04-30 14:55 ` [PATCH 06/15] powerpc/powernv: Remove OPALv1 support from opal console driver Nicholas Piggin
2018-04-30 14:55 ` [PATCH 07/15] powerpc/powernv: move opal console flushing to udbg Nicholas Piggin
2018-04-30 14:55 ` [PATCH 08/15] powerpc/powernv: implement opal_put_chars_atomic Nicholas Piggin
2018-05-01  9:48   ` Benjamin Herrenschmidt
2018-05-01 10:37     ` Nicholas Piggin
2018-05-07 10:35       ` Michael Ellerman
2018-05-08  3:36         ` Nicholas Piggin
2018-04-30 14:55 ` [PATCH 09/15] tty: hvc: remove unexplained "just in case" spin delay Nicholas Piggin
2018-04-30 14:55 ` [PATCH 10/15] tty: hvc: use mutex instead of spinlock for hvc_structs lock Nicholas Piggin
2018-08-13 11:22   ` [10/15] " Michael Ellerman
2018-04-30 14:55 ` [PATCH 11/15] tty: hvc: hvc_poll break hv read loop Nicholas Piggin
2018-08-13 11:23   ` [11/15] " Michael Ellerman
2018-04-30 14:55 ` [PATCH 12/15] tty: hvc: hvc_poll may sleep Nicholas Piggin
2018-08-13 11:23   ` [12/15] " Michael Ellerman
2018-04-30 14:55 ` [PATCH 13/15] tty: hvc: hvc_write " Nicholas Piggin
2018-08-13 11:23   ` [13/15] " Michael Ellerman
2018-04-30 14:55 ` [PATCH 14/15] tty: hvc: introduce the hv_ops.flush operation for hvc drivers Nicholas Piggin
2018-08-13 11:23   ` [14/15] " Michael Ellerman
2018-04-30 14:55 ` [PATCH 15/15] powerpc/powernv: provide a console flush operation for opal hvc driver Nicholas Piggin
2018-08-21 10:35   ` [15/15] " Michael Ellerman

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