linux/drivers/iommu
Eric Dumazet 0d87308cca iommu/iova: Avoid false sharing on fq_timer_on
In commit 14bd9a607f ("iommu/iova: Separate atomic variables
to improve performance") Jinyu Qi identified that the atomic_cmpxchg()
in queue_iova() was causing a performance loss and moved critical fields
so that the false sharing would not impact them.

However, avoiding the false sharing in the first place seems easy.
We should attempt the atomic_cmpxchg() no more than 100 times
per second. Adding an atomic_read() will keep the cache
line mostly shared.

This false sharing came with commit 9a005a800a
("iommu/iova: Add flush timer").

Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 9a005a800a ('iommu/iova: Add flush timer')
Cc: Jinyu Qi <jinyuqi@huawei.com>
Cc: Joerg Roedel <jroedel@suse.de>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2019-08-30 15:21:53 +02:00
..
amd_iommu_debugfs.c iommu/amd: Add basic debugfs infrastructure for AMD IOMMU 2018-07-06 14:06:30 +02:00
amd_iommu_init.c iommu/amd: Add support for X2APIC IOMMU interrupts 2019-07-23 17:41:52 +02:00
amd_iommu_proto.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
amd_iommu_types.h iommu/amd: Add support for X2APIC IOMMU interrupts 2019-07-23 17:41:52 +02:00
amd_iommu_v2.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
amd_iommu.c iommu/amd: Request passthrough mode from IOMMU core 2019-08-23 10:09:58 +02:00
arm-smmu-regs.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
arm-smmu-v3.c iommu/io-pgtable: Pass struct iommu_iotlb_gather to ->tlb_add_page() 2019-07-29 17:22:59 +01:00
arm-smmu.c iommu/io-pgtable: Pass struct iommu_iotlb_gather to ->tlb_add_page() 2019-07-29 17:22:59 +01:00
dma-iommu.c iommu: Introduce struct iommu_iotlb_gather for batching TLB flushes 2019-07-24 13:35:27 +01:00
dmar.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 320 2019-06-05 17:37:05 +02:00
exynos-iommu.c Merge branch 'for-joerg/batched-unmap' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into core 2019-08-20 11:09:43 +02:00
fsl_pamu_domain.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
fsl_pamu_domain.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
fsl_pamu.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
fsl_pamu.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
hyperv-iommu.c iommu/hyper-v: Add Hyper-V stub IOMMU driver 2019-02-28 11:12:16 +01:00
intel_irq_remapping.c iommu/vt-d: Cleanup unused variable 2019-07-01 14:24:01 +02:00
intel-iommu-debugfs.c iommu/vt-d: Print pasid table entries MSB to LSB in debugfs 2019-07-22 17:52:57 +02:00
intel-iommu.c iommu/vt-d: Request passthrough mode from IOMMU core 2019-08-23 10:09:58 +02:00
intel-pasid.c Merge branches 'x86/vt-d', 'x86/amd', 'arm/smmu', 'arm/omap', 'generic-dma-ops' and 'core' into next 2019-07-04 17:26:48 +02:00
intel-pasid.h iommu/vt-d: Introduce macros useful for dumping DMAR table 2019-05-27 16:16:09 +02:00
intel-svm.c Merge branches 'x86/vt-d', 'x86/amd', 'arm/smmu', 'arm/omap', 'generic-dma-ops' and 'core' into next 2019-07-04 17:26:48 +02:00
io-pgtable-arm-v7s.c iommu/io-pgtable: Pass struct iommu_iotlb_gather to ->tlb_add_page() 2019-07-29 17:22:59 +01:00
io-pgtable-arm.c iommu/io-pgtable: Pass struct iommu_iotlb_gather to ->tlb_add_page() 2019-07-29 17:22:59 +01:00
io-pgtable.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
iommu-debugfs.c iommu: Fix IOMMU debugfs fallout 2019-02-26 11:15:58 +01:00
iommu-sysfs.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
iommu-traces.c
iommu.c iommu: Disable passthrough mode when SME is active 2019-08-23 10:11:29 +02:00
iova.c iommu/iova: Avoid false sharing on fq_timer_on 2019-08-30 15:21:53 +02:00
ipmmu-vmsa.c iommu/io-pgtable: Pass struct iommu_iotlb_gather to ->unmap() 2019-07-29 17:22:59 +01:00
irq_remapping.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
irq_remapping.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
Kconfig iommu: Add virtio-iommu driver 2019-06-06 17:32:13 -04:00
Makefile iommu: Add virtio-iommu driver 2019-06-06 17:32:13 -04:00
msm_iommu_hw-8xxx.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 267 2019-06-05 17:30:29 +02:00
msm_iommu.c Merge branch 'for-joerg/batched-unmap' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into core 2019-08-20 11:09:43 +02:00
msm_iommu.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 267 2019-06-05 17:30:29 +02:00
mtk_iommu_v1.c iommu: Pass struct iommu_iotlb_gather to ->unmap() and ->iotlb_sync() 2019-07-29 17:22:52 +01:00
mtk_iommu.c iommu/io-pgtable: Pass struct iommu_iotlb_gather to ->tlb_add_page() 2019-07-29 17:22:59 +01:00
mtk_iommu.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
of_iommu.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 335 2019-06-05 17:37:06 +02:00
omap-iommu-debug.c Merge branches 'x86/vt-d', 'x86/amd', 'arm/smmu', 'arm/omap', 'generic-dma-ops' and 'core' into next 2019-07-04 17:26:48 +02:00
omap-iommu.c iommu: Pass struct iommu_iotlb_gather to ->unmap() and ->iotlb_sync() 2019-07-29 17:22:52 +01:00
omap-iommu.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
omap-iopgtable.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
qcom_iommu.c Merge branch 'for-joerg/batched-unmap' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into core 2019-08-20 11:09:43 +02:00
rockchip-iommu.c iommu: Pass struct iommu_iotlb_gather to ->unmap() and ->iotlb_sync() 2019-07-29 17:22:52 +01:00
s390-iommu.c iommu: Pass struct iommu_iotlb_gather to ->unmap() and ->iotlb_sync() 2019-07-29 17:22:52 +01:00
tegra-gart.c iommu: Pass struct iommu_iotlb_gather to ->unmap() and ->iotlb_sync() 2019-07-29 17:22:52 +01:00
tegra-smmu.c iommu: Pass struct iommu_iotlb_gather to ->unmap() and ->iotlb_sync() 2019-07-29 17:22:52 +01:00
virtio-iommu.c Merge branch 'for-joerg/batched-unmap' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into core 2019-08-20 11:09:43 +02:00