Edited report from pahole on amd64 host:
struct PCNetState_st {
...
uint16_t bcr[32]; /* 340 64 */
/* XXX 4 bytes hole, try to pack */
...
int tx_busy; /* 4520 4 */
/* XXX 4 bytes hole, try to pack */
qemu_irq irq; /* 4528 8 */
void (*phys_mem_read)(void *,
target_phys_addr_t, uint8_t *, int, int); /* 4536 8 */
/* --- cacheline 71 boundary (4544 bytes) --- */
void (*phys_mem_write)(void *,
target_phys_addr_t, uint8_t *, int, int); /* 4544 8 */
void * dma_opaque; /* 4552 8 */
int looptest; /* 4560 4 */
/* size: 4568, cachelines: 72 */
/* sum members: 4556, holes: 2, sum holes: 8 */
/* padding: 4 */
/* last cacheline: 24 bytes */
}; /* definitions: 2 */
Fix by rearranging the structure to avoid padding.
Signed-off-by: Blue Swirl <blauwir...@gmail.com>
---
hw/pcnet.h | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/hw/pcnet.h b/hw/pcnet.h
index 534bdf9..9a7b122 100644
--- a/hw/pcnet.h
+++ b/hw/pcnet.h
@@ -11,15 +11,15 @@ struct PCNetState_st {
NICState *nic;
NICConf conf;
QEMUTimer *poll_timer;
- int rap, isr, lnkst;
+ int rap, isr;
uint32_t rdra, tdra;
+ uint64_t timer;
uint8_t prom[16];
uint16_t csr[128];
uint16_t bcr[32];
- uint64_t timer;
int mmio_index, xmit_pos;
uint8_t buffer[4096];
- int tx_busy;
+ int tx_busy, lnkst;
qemu_irq irq;
void (*phys_mem_read)(void *dma_opaque, target_phys_addr_t addr,
uint8_t *buf, int len, int do_bswap);
--
1.6.2.4
From 6eda685443fbe094e7a551149c52dfdc9e6be6a6 Mon Sep 17 00:00:00 2001
Message-Id: <6eda685443fbe094e7a551149c52dfdc9e6be6a6.1312750600.git.blauwir...@gmail.com>
In-Reply-To: <54eae070f9056790fa41b468360d23cdd17503f4.1312750600.git.blauwir...@gmail.com>
References: <54eae070f9056790fa41b468360d23cdd17503f4.1312750600.git.blauwir...@gmail.com>
From: Blue Swirl <blauwir...@gmail.com>
Date: Sun, 7 Aug 2011 19:38:49 +0000
Subject: [PATCH 08/11] pcnet: void structure holes spotted by pahole
Edited report from pahole on amd64 host:
struct PCNetState_st {
...
uint16_t bcr[32]; /* 340 64 */
/* XXX 4 bytes hole, try to pack */
...
int tx_busy; /* 4520 4 */
/* XXX 4 bytes hole, try to pack */
qemu_irq irq; /* 4528 8 */
void (*phys_mem_read)(void *, target_phys_addr_t, uint8_t *, int, int); /* 4536 8 */
/* --- cacheline 71 boundary (4544 bytes) --- */
void (*phys_mem_write)(void *, target_phys_addr_t, uint8_t *, int, int); /* 4544 8 */
void * dma_opaque; /* 4552 8 */
int looptest; /* 4560 4 */
/* size: 4568, cachelines: 72 */
/* sum members: 4556, holes: 2, sum holes: 8 */
/* padding: 4 */
/* last cacheline: 24 bytes */
}; /* definitions: 2 */
Fix by rearranging structures to avoid padding.
Signed-off-by: Blue Swirl <blauwir...@gmail.com>
---
hw/pcnet.h | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/hw/pcnet.h b/hw/pcnet.h
index 534bdf9..9a7b122 100644
--- a/hw/pcnet.h
+++ b/hw/pcnet.h
@@ -11,15 +11,15 @@ struct PCNetState_st {
NICState *nic;
NICConf conf;
QEMUTimer *poll_timer;
- int rap, isr, lnkst;
+ int rap, isr;
uint32_t rdra, tdra;
+ uint64_t timer;
uint8_t prom[16];
uint16_t csr[128];
uint16_t bcr[32];
- uint64_t timer;
int mmio_index, xmit_pos;
uint8_t buffer[4096];
- int tx_busy;
+ int tx_busy, lnkst;
qemu_irq irq;
void (*phys_mem_read)(void *dma_opaque, target_phys_addr_t addr,
uint8_t *buf, int len, int do_bswap);
--
1.7.2.5
