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From cde8161f9ee466655588b66a106276044b2fc282 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri, 1 Mar 2019 18:13:27 +0100
Subject: [PATCH] USB: usb.h: tweak struct urb to remove wasted space
By moving one field around in 'struct urb' we reduce the size of the
structure by 8 bytes.
Before the patch on x86_64 the overall size of the structure as reported
by pahole was:
/* size: 192, cachelines: 3, members: 30 */
/* sum members: 184, holes: 2, sum holes: 8 */
After the patch we now have:
/* size: 184, cachelines: 3, members: 30 */
/* last cacheline: 56 bytes */
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/linux/usb.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -1545,10 +1545,10 @@ typedef void (*usb_complete_t)(struct ur
struct urb {
/* private: usb core and host controller only fields in the urb */
struct kref kref; /* reference count of the URB */
+ int unlinked; /* unlink error code */
void *hcpriv; /* private data for host controller */
atomic_t use_count; /* concurrent submissions counter */
atomic_t reject; /* submissions will fail */
- int unlinked; /* unlink error code */
/* public: documented fields in the urb that can be used by drivers */
struct list_head urb_list; /* list head for use by the urb's
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