| Message ID | 334a5e2d8c9a05ce7cbac126bfbc6b39d05e1c9c.1676635829.git.christophe.jaillet@wanadoo.fr (mailing list archive) |
|---|---|
| State | RFC, archived |
| Headers | show |
| Series | ACPI: EC: Reorder fields in 'struct acpi_ec' | expand |
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index 06ad497067ac..acfdd23c8dec 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -179,6 +179,8 @@ struct acpi_ec { unsigned long command_addr; unsigned long data_addr; bool global_lock; + bool busy_polling; + unsigned int polling_guard; unsigned long flags; unsigned long reference_count; struct mutex mutex; @@ -192,8 +194,6 @@ struct acpi_ec { unsigned int events_to_process; unsigned int events_in_progress; unsigned int queries_in_progress; - bool busy_polling; - unsigned int polling_guard; }; extern struct acpi_ec *first_ec;
Group some variables based on their sizes to reduce hole and avoid padding. On x86_64, this shrinks the size of 'struct acpi_ec' from 520 to 512 bytes. This size is much better when the struct is kmalloc()'ed. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> --- Using pahole Before: ====== struct acpi_ec { acpi_handle handle; /* 0 8 */ acpi_handle address_space_handler_holder; /* 8 8 */ int gpe; /* 16 4 */ int irq; /* 20 4 */ long unsigned int command_addr; /* 24 8 */ long unsigned int data_addr; /* 32 8 */ bool global_lock; /* 40 1 */ /* XXX 7 bytes hole, try to pack */ long unsigned int flags; /* 48 8 */ long unsigned int reference_count; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ struct mutex mutex; /* 64 160 */ /* --- cacheline 3 boundary (192 bytes) was 32 bytes ago --- */ wait_queue_head_t wait; /* 224 88 */ /* --- cacheline 4 boundary (256 bytes) was 56 bytes ago --- */ struct list_head list; /* 312 16 */ /* --- cacheline 5 boundary (320 bytes) was 8 bytes ago --- */ struct transaction * curr; /* 328 8 */ spinlock_t lock; /* 336 72 */ /* --- cacheline 6 boundary (384 bytes) was 24 bytes ago --- */ struct work_struct work; /* 408 80 */ /* --- cacheline 7 boundary (448 bytes) was 40 bytes ago --- */ long unsigned int timestamp; /* 488 8 */ enum acpi_ec_event_state event_state; /* 496 4 */ unsigned int events_to_process; /* 500 4 */ unsigned int events_in_progress; /* 504 4 */ unsigned int queries_in_progress; /* 508 4 */ /* --- cacheline 8 boundary (512 bytes) --- */ bool busy_polling; /* 512 1 */ /* XXX 3 bytes hole, try to pack */ unsigned int polling_guard; /* 516 4 */ /* size: 520, cachelines: 9, members: 22 */ /* sum members: 510, holes: 2, sum holes: 10 */ /* last cacheline: 8 bytes */ }; After: ===== struct acpi_ec { acpi_handle handle; /* 0 8 */ acpi_handle address_space_handler_holder; /* 8 8 */ int gpe; /* 16 4 */ int irq; /* 20 4 */ long unsigned int command_addr; /* 24 8 */ long unsigned int data_addr; /* 32 8 */ bool global_lock; /* 40 1 */ bool busy_polling; /* 41 1 */ /* XXX 2 bytes hole, try to pack */ unsigned int polling_guard; /* 44 4 */ long unsigned int flags; /* 48 8 */ long unsigned int reference_count; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ struct mutex mutex; /* 64 160 */ /* --- cacheline 3 boundary (192 bytes) was 32 bytes ago --- */ wait_queue_head_t wait; /* 224 88 */ /* --- cacheline 4 boundary (256 bytes) was 56 bytes ago --- */ struct list_head list; /* 312 16 */ /* --- cacheline 5 boundary (320 bytes) was 8 bytes ago --- */ struct transaction * curr; /* 328 8 */ spinlock_t lock; /* 336 72 */ /* --- cacheline 6 boundary (384 bytes) was 24 bytes ago --- */ struct work_struct work; /* 408 80 */ /* --- cacheline 7 boundary (448 bytes) was 40 bytes ago --- */ long unsigned int timestamp; /* 488 8 */ enum acpi_ec_event_state event_state; /* 496 4 */ unsigned int events_to_process; /* 500 4 */ unsigned int events_in_progress; /* 504 4 */ unsigned int queries_in_progress; /* 508 4 */ /* size: 512, cachelines: 8, members: 22 */ /* sum members: 510, holes: 1, sum holes: 2 */ }; --- drivers/acpi/internal.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)