From: Reinette Chatre Date: Thu, 11 May 2023 15:44:35 +0000 (-0700) Subject: vfio/pci: Use bitfield for struct vfio_pci_core_device flags X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9cd0f6d5cbb6fda09aa83beb8146c287a552017e;p=linux.git vfio/pci: Use bitfield for struct vfio_pci_core_device flags 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 Signed-off-by: Reinette Chatre Reviewed-by: Kevin Tian Acked-by: Thomas Gleixner Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/cf34bf0499c889554a8105eeb18cc0ab673005be.1683740667.git.reinette.chatre@intel.com Signed-off-by: Alex Williamson --- diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h index 148fd1ae6c1c4..adb47e2914d74 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;