Here's a small patch to reduce the nr. of pointer dereferences in
drivers/pci/hotplug/pciehp_core.c
Benefits:
- micro speed optimization due to fewer pointer derefs
- generated code is slightly smaller
- small line length cleanup
- better readability
Please consider applying.
Signed-off-by: Jesper Juhl <[email protected]>
---
drivers/pci/hotplug/pciehp_core.c | 90 +++++++++++++++++++++-----------------
1 files changed, 50 insertions(+), 40 deletions(-)
orig:
text data bss dec hex filename
4910 436 24 5370 14fa drivers/pci/hotplug/pciehp_core.o
patched:
text data bss dec hex filename
4889 436 24 5349 14e5 drivers/pci/hotplug/pciehp_core.o
--- linux-2.6.15-rc5-git1-orig/drivers/pci/hotplug/pciehp_core.c 2005-12-04 18:48:04.000000000 +0100
+++ linux-2.6.15-rc5-git1/drivers/pci/hotplug/pciehp_core.c 2005-12-11 05:46:58.000000000 +0100
@@ -103,7 +103,10 @@ static void release_slot(struct hotplug_
static int init_slots(struct controller *ctrl)
{
- struct slot *new_slot;
+ struct slot *slot;
+ struct hpc_ops *hpc_ops;
+ struct hotplug_slot *hotplug_slot;
+ struct hotplug_slot_info *hotplug_slot_info;
u8 number_of_slots;
u8 slot_device;
u32 slot_number;
@@ -114,59 +117,66 @@ static int init_slots(struct controller
slot_number = ctrl->first_slot;
while (number_of_slots) {
- new_slot = kmalloc(sizeof(*new_slot), GFP_KERNEL);
- if (!new_slot)
+ slot = kmalloc(sizeof(*slot), GFP_KERNEL);
+ if (!slot)
goto error;
- memset(new_slot, 0, sizeof(struct slot));
- new_slot->hotplug_slot =
- kmalloc(sizeof(*(new_slot->hotplug_slot)),
+ memset(slot, 0, sizeof(struct slot));
+ slot->hotplug_slot =
+ kmalloc(sizeof(*(slot->hotplug_slot)),
GFP_KERNEL);
- if (!new_slot->hotplug_slot)
+ if (!slot->hotplug_slot)
goto error_slot;
- memset(new_slot->hotplug_slot, 0, sizeof(struct hotplug_slot));
+ hotplug_slot = slot->hotplug_slot;
+ memset(hotplug_slot, 0, sizeof(struct hotplug_slot));
- new_slot->hotplug_slot->info =
- kmalloc(sizeof(*(new_slot->hotplug_slot->info)),
+ hotplug_slot->info =
+ kmalloc(sizeof(*(hotplug_slot->info)),
GFP_KERNEL);
- if (!new_slot->hotplug_slot->info)
+ if (!hotplug_slot->info)
goto error_hpslot;
- memset(new_slot->hotplug_slot->info, 0,
+ hotplug_slot_info = hotplug_slot->info;
+ memset(hotplug_slot_info, 0,
sizeof(struct hotplug_slot_info));
- new_slot->hotplug_slot->name = kmalloc(SLOT_NAME_SIZE,
- GFP_KERNEL);
- if (!new_slot->hotplug_slot->name)
+ hotplug_slot->name = kmalloc(SLOT_NAME_SIZE, GFP_KERNEL);
+ if (!hotplug_slot->name)
goto error_info;
- new_slot->ctrl = ctrl;
- new_slot->bus = ctrl->slot_bus;
- new_slot->device = slot_device;
- new_slot->hpc_ops = ctrl->hpc_ops;
+ slot->ctrl = ctrl;
+ slot->bus = ctrl->slot_bus;
+ slot->device = slot_device;
+ slot->hpc_ops = hpc_ops = ctrl->hpc_ops;
- new_slot->number = ctrl->first_slot;
- new_slot->hp_slot = slot_device - ctrl->slot_device_offset;
+ slot->number = ctrl->first_slot;
+ slot->hp_slot = slot_device - ctrl->slot_device_offset;
/* register this slot with the hotplug pci core */
- new_slot->hotplug_slot->private = new_slot;
- new_slot->hotplug_slot->release = &release_slot;
- make_slot_name(new_slot->hotplug_slot->name, SLOT_NAME_SIZE, new_slot);
- new_slot->hotplug_slot->ops = &pciehp_hotplug_slot_ops;
-
- new_slot->hpc_ops->get_power_status(new_slot, &(new_slot->hotplug_slot->info->power_status));
- new_slot->hpc_ops->get_attention_status(new_slot, &(new_slot->hotplug_slot->info->attention_status));
- new_slot->hpc_ops->get_latch_status(new_slot, &(new_slot->hotplug_slot->info->latch_status));
- new_slot->hpc_ops->get_adapter_status(new_slot, &(new_slot->hotplug_slot->info->adapter_status));
-
- dbg("Registering bus=%x dev=%x hp_slot=%x sun=%x slot_device_offset=%x\n",
- new_slot->bus, new_slot->device, new_slot->hp_slot, new_slot->number, ctrl->slot_device_offset);
- result = pci_hp_register (new_slot->hotplug_slot);
+ hotplug_slot->private = slot;
+ hotplug_slot->release = &release_slot;
+ make_slot_name(hotplug_slot->name, SLOT_NAME_SIZE, slot);
+ hotplug_slot->ops = &pciehp_hotplug_slot_ops;
+
+ hpc_ops->get_power_status(slot,
+ &(hotplug_slot_info->power_status));
+ hpc_ops->get_attention_status(slot,
+ &(hotplug_slot_info->attention_status));
+ hpc_ops->get_latch_status(slot,
+ &(hotplug_slot_info->latch_status));
+ hpc_ops->get_adapter_status(slot,
+ &(hotplug_slot_info->adapter_status));
+
+ dbg("Registering bus=%x dev=%x hp_slot=%x sun=%x "
+ "slot_device_offset=%x\n",
+ slot->bus, slot->device, slot->hp_slot, slot->number,
+ ctrl->slot_device_offset);
+ result = pci_hp_register(hotplug_slot);
if (result) {
err ("pci_hp_register failed with error %d\n", result);
goto error_name;
}
- new_slot->next = ctrl->slot;
- ctrl->slot = new_slot;
+ slot->next = ctrl->slot;
+ ctrl->slot = slot;
number_of_slots--;
slot_device++;
@@ -176,13 +186,13 @@ static int init_slots(struct controller
return 0;
error_name:
- kfree(new_slot->hotplug_slot->name);
+ kfree(hotplug_slot->name);
error_info:
- kfree(new_slot->hotplug_slot->info);
+ kfree(hotplug_slot_info);
error_hpslot:
- kfree(new_slot->hotplug_slot);
+ kfree(hotplug_slot);
error_slot:
- kfree(new_slot);
+ kfree(slot);
error:
return result;
}
Jesper Juhl schrieb:
> --- linux-2.6.15-rc5-git1-orig/drivers/pci/hotplug/pciehp_core.c 2005-12-04 18:48:04.000000000 +0100
> +++ linux-2.6.15-rc5-git1/drivers/pci/hotplug/pciehp_core.c 2005-12-11 05:46:58.000000000 +0100
@@ -114,59 +117,66 @@ static int init_slots(struct controller
slot_number = ctrl->first_slot;
while (number_of_slots) {
- new_slot = kmalloc(sizeof(*new_slot), GFP_KERNEL);
- if (!new_slot)
+ slot = kmalloc(sizeof(*slot), GFP_KERNEL);
+ if (!slot)
goto error;
- memset(new_slot, 0, sizeof(struct slot));
- new_slot->hotplug_slot =
- kmalloc(sizeof(*(new_slot->hotplug_slot)),
+ memset(slot, 0, sizeof(struct slot));
+ slot->hotplug_slot =
+ kmalloc(sizeof(*(slot->hotplug_slot)),
Just one suggestion:
In your patches I've seen a lot of kmalloc + memset calls. Perhaps you
can convert them to kzalloc? This would improve readability even more.
Thanks,
Gregor
On 12/11/05, Gregor Jasny <[email protected]> wrote:
> Jesper Juhl schrieb:
> > --- linux-2.6.15-rc5-git1-orig/drivers/pci/hotplug/pciehp_core.c 2005-12-04 18:48:04.000000000 +0100
> > +++ linux-2.6.15-rc5-git1/drivers/pci/hotplug/pciehp_core.c 2005-12-11 05:46:58.000000000 +0100
> @@ -114,59 +117,66 @@ static int init_slots(struct controller
> slot_number = ctrl->first_slot;
>
> while (number_of_slots) {
> - new_slot = kmalloc(sizeof(*new_slot), GFP_KERNEL);
> - if (!new_slot)
> + slot = kmalloc(sizeof(*slot), GFP_KERNEL);
> + if (!slot)
> goto error;
>
> - memset(new_slot, 0, sizeof(struct slot));
> - new_slot->hotplug_slot =
> - kmalloc(sizeof(*(new_slot->hotplug_slot)),
> + memset(slot, 0, sizeof(struct slot));
> + slot->hotplug_slot =
> + kmalloc(sizeof(*(slot->hotplug_slot)),
>
> Just one suggestion:
>
> In your patches I've seen a lot of kmalloc + memset calls. Perhaps you
> can convert them to kzalloc? This would improve readability even more.
>
Good idea, but I think I'll do that as a seperate round of patches at
a later date. Added to my todo list. Thanks.
--
Jesper Juhl <[email protected]>
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