From: Juergen Gross <jgross@suse.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org,
virtualization@lists.linux.dev, kvm@vger.kernel.org,
linux-hwmon@vger.kernel.org, linux-block@vger.kernel.org
Cc: Juergen Gross <jgross@suse.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Ajay Kaher <ajay.kaher@broadcom.com>,
Alexey Makhalov <alexey.makhalov@broadcom.com>,
Broadcom internal kernel review list
<bcm-kernel-feedback-list@broadcom.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
xen-devel@lists.xenproject.org, Jean Delvare <jdelvare@suse.com>,
Guenter Roeck <linux@roeck-us.net>,
Denis Efremov <efremov@linux.com>, Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 0/5] x86: Cleanups around slow_down_io()
Date: Wed, 26 Nov 2025 17:20:13 +0100 [thread overview]
Message-ID: <20251126162018.5676-1-jgross@suse.com> (raw)
While looking at paravirt cleanups I stumbled over slow_down_io() and
the related REALLY_SLOW_IO define.
Especially REALLY_SLOW_IO is a mess, which is proven by 2 completely
wrong use cases.
Do several cleanups, resulting in a deletion of REALLY_SLOW_IO and the
io_delay() paravirt function hook.
Patches 2 and 3 are not changing any functionality, but maybe they
should? As the potential bug has been present for more than a decade
now, I went with just deleting the useless "#define REALLY_SLOW_IO".
The alternative would be to do something similar as in patch 5.
Juergen Gross (5):
x86/paravirt: Replace io_delay() hook with a bool
hwmon/lm78: Drop REALLY_SLOW_IO setting
hwmon/w83781d: Drop REALLY_SLOW_IO setting
block/floppy: Don't use REALLY_SLOW_IO for delays
x86/io: Remove REALLY_SLOW_IO handling
arch/x86/include/asm/floppy.h | 27 ++++++++++++++++++++++-----
arch/x86/include/asm/io.h | 12 +++++-------
arch/x86/include/asm/paravirt.h | 11 +----------
arch/x86/include/asm/paravirt_types.h | 3 +--
arch/x86/kernel/cpu/vmware.c | 2 +-
arch/x86/kernel/kvm.c | 8 +-------
arch/x86/kernel/paravirt.c | 3 +--
arch/x86/xen/enlighten_pv.c | 6 +-----
drivers/block/floppy.c | 2 --
drivers/hwmon/lm78.c | 5 +++--
drivers/hwmon/w83781d.c | 5 +++--
11 files changed, 39 insertions(+), 45 deletions(-)
--
2.51.0
next reply other threads:[~2025-11-26 16:20 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-26 16:20 Juergen Gross [this message]
2025-11-26 16:20 ` [PATCH 1/5] x86/paravirt: Replace io_delay() hook with a bool Juergen Gross
2025-11-26 16:20 ` [PATCH 2/5] hwmon/lm78: Drop REALLY_SLOW_IO setting Juergen Gross
2025-11-26 17:04 ` Guenter Roeck
2025-11-26 16:20 ` [PATCH 3/5] hwmon/w83781d: " Juergen Gross
2025-11-26 17:05 ` Guenter Roeck
2025-11-26 16:20 ` [PATCH 4/5] block/floppy: Don't use REALLY_SLOW_IO for delays Juergen Gross
2025-11-26 16:20 ` [PATCH 5/5] x86/io: Remove REALLY_SLOW_IO handling Juergen Gross
2025-11-26 17:08 ` [PATCH 0/5] x86: Cleanups around slow_down_io() Guenter Roeck
2025-12-14 8:05 ` Ingo Molnar
2025-12-15 6:36 ` Jürgen Groß
2025-12-16 13:48 ` Ingo Molnar
2025-12-16 13:55 ` Jürgen Groß
2025-12-16 15:32 ` H. Peter Anvin
2025-12-16 19:59 ` David Laight
2025-12-16 21:50 ` H. Peter Anvin
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