struct vfio_pci_core_device contains eleven boolean flags.
Boolean flags clearly indicate their usage but space usage
starts to be a concern when there are many.
An upcoming change adds another boolean flag to
struct vfio_pci_core_device, thereby increasing the concern
that the boolean flags are consuming unnecessary space.
Transition the boolean flags to use bitfields. On a system that
uses one byte per boolean this reduces the space consumed
by existing flags from 11 bytes to 2 bytes with room for
a few more flags without increasing the structure's size.
Suggested-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
---
Changes since V4:
- Add Kevin's Reviewed-by tag. (Kevin)
Changes since V3:
- New patch. (Jason)
include/linux/vfio_pci_core.h | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h
index 148fd1ae6c1c..adb47e2914d7 100644
--- a/include/linux/vfio_pci_core.h
+++ b/include/linux/vfio_pci_core.h
@@ -68,17 +68,17 @@ struct vfio_pci_core_device {
u16 msix_size;
u32 msix_offset;
u32 rbar[7];
- bool pci_2_3;
- bool virq_disabled;
- bool reset_works;
- bool extended_caps;
- bool bardirty;
- bool has_vga;
- bool needs_reset;
- bool nointx;
- bool needs_pm_restore;
- bool pm_intx_masked;
- bool pm_runtime_engaged;
+ bool pci_2_3:1;
+ bool virq_disabled:1;
+ bool reset_works:1;
+ bool extended_caps:1;
+ bool bardirty:1;
+ bool has_vga:1;
+ bool needs_reset:1;
+ bool nointx:1;
+ bool needs_pm_restore:1;
+ bool pm_intx_masked:1;
+ bool pm_runtime_engaged:1;
struct pci_saved_state *pci_saved_state;
struct pci_saved_state *pm_save;
int ioeventfds_nr;
--
2.34.1
