[Qemu-devel] [PATCH 08/11] pcnet: avoid structure holes spotted by pahole

[Blue Swirl]

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 <address@hidden>
---
 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

0008-pcnet-void-structure-holes-spotted-by-pahole.patch
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