From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>, Borislav Petkov <bp@alien8.de>,
Dan Williams <dan.j.williams@intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@redhat.com>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@linux.intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Tony Luck <tony.luck@intel.com>,
the arch/x86 maintainers <x86@kernel.org>
Subject: Re: [PATCH 2/4] ACPI: PM: Remove redundant cache flushing
Date: Thu, 9 Dec 2021 16:32:17 +0300 [thread overview]
Message-ID: <20211209133217.omm3mzchsfippwjc@black.fi.intel.com> (raw)
In-Reply-To: <CAJZ5v0hGnvX2a1bsoUSqV4Vf0LE6P6wTjk4ZPT7JTLvSAL7z_g@mail.gmail.com>
On Tue, Dec 07, 2021 at 05:35:38PM +0100, Rafael J. Wysocki wrote:
> I don't think this is needed for S2, because the function doesn't do
> anything low-level in that case and simply returns (IOW, S2 isn't
> really supported).
Updated patch is below. Does it look good?
From 5eb4ec7d8dd463ba186b779dcef2a802d999c59c Mon Sep 17 00:00:00 2001
From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Date: Thu, 9 Dec 2021 16:08:02 +0300
Subject: [PATCH 1/2] ACPI: PM: Remove redundant cache flushing
ACPICA code takes care about cache flushing on S1/S2/S3 in
acpi_hw_extended_sleep() and acpi_hw_legacy_sleep().
acpi_suspend_enter() calls into ACPICA code via acpi_enter_sleep_state()
for S1 or x86_acpi_suspend_lowlevel() for S3.
acpi_sleep_prepare() call tree:
__acpi_pm_prepare()
acpi_pm_prepare()
acpi_suspend_ops::prepare_late()
acpi_hibernation_ops::pre_snapshot()
acpi_hibernation_ops::prepare()
acpi_suspend_begin_old()
acpi_suspend_begin_old::begin()
acpi_hibernation_begin_old()
acpi_hibernation_ops_old::acpi_hibernation_begin_old()
acpi_power_off_prepare()
pm_power_off_prepare()
Hibernation (S4) and Power Off (S5) don't require cache flushing. So,
the only interesting callsites are acpi_suspend_ops::prepare_late() and
acpi_suspend_begin_old::begin(). Both of them have cache flush on
->enter() operation in acpi_suspend_enter().
Remove redundant ACPI_FLUSH_CPU_CACHE() in acpi_sleep_prepare() and
acpi_suspend_enter().
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
drivers/acpi/sleep.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index eaa47753b758..5ca6c223ba3d 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -73,7 +73,6 @@ static int acpi_sleep_prepare(u32 acpi_state)
acpi_set_waking_vector(acpi_wakeup_address);
}
- ACPI_FLUSH_CPU_CACHE();
#endif
pr_info("Preparing to enter system sleep state S%d\n", acpi_state);
acpi_enable_wakeup_devices(acpi_state);
@@ -566,8 +565,6 @@ static int acpi_suspend_enter(suspend_state_t pm_state)
u32 acpi_state = acpi_target_sleep_state;
int error;
- ACPI_FLUSH_CPU_CACHE();
-
trace_suspend_resume(TPS("acpi_suspend"), acpi_state, true);
switch (acpi_state) {
case ACPI_STATE_S1:
--
Kirill A. Shutemov
next prev parent reply other threads:[~2021-12-09 13:32 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <YZPbQVwWOJCrAH78@zn.tnic>
2021-11-19 4:03 ` [PATCH v2] x86: Skip WBINVD instruction for VM guest Kuppuswamy Sathyanarayanan
2021-11-25 0:40 ` Thomas Gleixner
2021-12-02 22:21 ` Kirill A. Shutemov
2021-12-02 22:38 ` Dave Hansen
2021-12-02 23:48 ` Thomas Gleixner
2021-12-03 23:49 ` Kirill A. Shutemov
2021-12-04 0:20 ` Dave Hansen
2021-12-04 0:54 ` Kirill A. Shutemov
2021-12-06 15:35 ` Dave Hansen
2021-12-06 16:39 ` Dan Williams
2021-12-06 16:53 ` Dave Hansen
2021-12-06 17:51 ` Dan Williams
2021-12-04 20:27 ` Rafael J. Wysocki
2021-12-06 12:29 ` [PATCH 0/4] ACPI/ACPICA: Only flush caches on S1/S2/S3 and C3 Kirill A. Shutemov
2021-12-06 12:29 ` [PATCH 1/4] ACPICA: Do not flush cache for on entering S4 and S5 Kirill A. Shutemov
2021-12-08 14:58 ` Rafael J. Wysocki
2021-12-06 12:29 ` [PATCH 2/4] ACPI: PM: Remove redundant cache flushing Kirill A. Shutemov
2021-12-07 16:35 ` Rafael J. Wysocki
2021-12-09 13:32 ` Kirill A. Shutemov [this message]
2021-12-17 18:04 ` Rafael J. Wysocki
2021-12-06 12:29 ` [PATCH 3/4] ACPI: processor idle: Only flush cache on entering C3 Kirill A. Shutemov
2021-12-06 15:03 ` Peter Zijlstra
2021-12-08 16:26 ` Rafael J. Wysocki
2021-12-09 13:33 ` Kirill A. Shutemov
2021-12-17 17:58 ` Rafael J. Wysocki
2021-12-06 12:29 ` [PATCH 4/4] ACPI: PM: Avoid cache flush on entering S4 Kirill A. Shutemov
2021-12-08 15:10 ` Rafael J. Wysocki
2021-12-08 16:04 ` Kirill A. Shutemov
2021-12-08 16:16 ` Rafael J. Wysocki
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