From: Sasha Levin <sashal@kernel.org>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org,
virtualization@lists.linux-foundation.org
Subject: Re: [PATCH AUTOSEL 5.12 42/43] virtio: fix up virtio_disable_cb
Date: Sat, 17 Jul 2021 21:41:26 -0400 [thread overview]
Message-ID: <YPOGxjBcq6f4l+0v@sashalap> (raw)
In-Reply-To: <20210711002242-mutt-send-email-mst@kernel.org>
On Sun, Jul 11, 2021 at 12:23:59AM -0400, Michael S. Tsirkin wrote:
>On Sat, Jul 10, 2021 at 07:49:14PM -0400, Sasha Levin wrote:
>> From: "Michael S. Tsirkin" <mst@redhat.com>
>>
>> [ Upstream commit 8d622d21d24803408b256d96463eac4574dcf067 ]
>>
>> virtio_disable_cb is currently a nop for split ring with event index.
>> This is because it used to be always called from a callback when we know
>> device won't trigger more events until we update the index. However,
>> now that we run with interrupts enabled a lot we also poll without a
>> callback so that is different: disabling callbacks will help reduce the
>> number of spurious interrupts.
>> Further, if using event index with a packed ring, and if being called
>> from a callback, we actually do disable interrupts which is unnecessary.
>>
>> Fix both issues by tracking whenever we get a callback. If that is
>> the case disabling interrupts with event index can be a nop.
>> If not the case disable interrupts. Note: with a split ring
>> there's no explicit "no interrupts" value. For now we write
>> a fixed value so our chance of triggering an interupt
>> is 1/ring size. It's probably better to write something
>> related to the last used index there to reduce the chance
>> even further. For now I'm keeping it simple.
>>
>> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
>> Signed-off-by: Sasha Levin <sashal@kernel.org>
>
>I am not sure we want this in stable yet. It should in theory
>fix the reported interrupt storms but the reporter is on vacation.
Sure, I'll drop it for now. Let me know when you want it re-added.
Thanks!
--
Thanks,
Sasha
next prev parent reply other threads:[~2021-07-18 1:41 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-10 23:48 [PATCH AUTOSEL 5.12 01/43] power: supply: sc27xx: Add missing MODULE_DEVICE_TABLE Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 02/43] power: supply: sc2731_charger: " Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 03/43] f2fs: fix to avoid racing on fsync_entry_slab by multi filesystem instances Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 04/43] pwm: spear: Don't modify HW state in .remove callback Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 05/43] PCI: ftpci100: Rename macro name collision Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 06/43] power: supply: ab8500: Avoid NULL pointers Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 07/43] PCI: hv: Fix a race condition when removing the device Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 08/43] power: supply: max17042: Do not enforce (incorrect) interrupt trigger type Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 09/43] power: reset: gpio-poweroff: add missing MODULE_DEVICE_TABLE Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 10/43] ARM: 9087/1: kprobes: test-thumb: fix for LLVM_IAS=1 Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 11/43] PCI/P2PDMA: Avoid pci_get_slot(), which may sleep Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 12/43] NFSv4: Fix delegation return in cases where we have to retry Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 13/43] PCI: pciehp: Ignore Link Down/Up caused by DPC Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 14/43] PCI: Dynamically map ECAM regions Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 15/43] watchdog: Fix possible use-after-free in wdt_startup() Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 16/43] watchdog: sc520_wdt: Fix possible use-after-free in wdt_turnoff() Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 17/43] watchdog: Fix possible use-after-free by calling del_timer_sync() Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 18/43] watchdog: imx_sc_wdt: fix pretimeout Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 19/43] watchdog: iTCO_wdt: Account for rebooting on second timeout Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 20/43] x86/fpu: Return proper error codes from user access functions Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 21/43] remoteproc: core: Fix cdev remove and rproc del Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 22/43] PCI: tegra: Add missing MODULE_DEVICE_TABLE Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 23/43] orangefs: fix orangefs df output Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 24/43] ceph: remove bogus checks and WARN_ONs from ceph_set_page_dirty Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 25/43] drm/gma500: Add the missed drm_gem_object_put() in psb_user_framebuffer_create() Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 26/43] NFS: nfs_find_open_context() may only select open files Sasha Levin
2021-07-10 23:48 ` [PATCH AUTOSEL 5.12 27/43] power: reset: regulator-poweroff: add missing MODULE_DEVICE_TABLE Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.12 28/43] power: supply: charger-manager: " Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.12 29/43] power: supply: ab8500: " Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.12 30/43] power: supply: axp288_fuel_gauge: Make "T3 MRD" no_battery_list DMI entry more generic Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.12 31/43] drm/amdgpu: fix Navi1x tcp power gating hang when issuing lightweight invalidaiton Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.12 32/43] drm/amdkfd: fix sysfs kobj leak Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.12 33/43] pwm: img: Fix PM reference leak in img_pwm_enable() Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.12 34/43] pwm: tegra: Don't modify HW state in .remove callback Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.12 35/43] ACPI: AMBA: Fix resource name in /proc/iomem Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.12 36/43] ACPI: video: Add quirk for the Dell Vostro 3350 Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.12 37/43] PCI: rockchip: Register IRQ handlers after device and data are ready Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.12 38/43] ext4: fix WARN_ON_ONCE(!buffer_uptodate) after an error writing the superblock Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.12 39/43] virtio-blk: Fix memory leak among suspend/resume procedure Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.12 40/43] virtio_net: Fix error handling in virtnet_restore() Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.12 41/43] virtio_console: Assure used length from device is limited Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.12 42/43] virtio: fix up virtio_disable_cb Sasha Levin
2021-07-11 4:23 ` Michael S. Tsirkin
2021-07-18 1:41 ` Sasha Levin [this message]
2021-07-10 23:49 ` [PATCH AUTOSEL 5.12 43/43] block: fix the problem of io_ticks becoming smaller Sasha Levin
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