From: Paolo Bonzini <pbonzini@redhat.com>
To: Fam Zheng <famz@redhat.com>, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH v2 2/2] virtio-scsi: Optimize virtio_scsi_init_req
Date: Mon, 15 Sep 2014 12:17:20 +0200 [thread overview]
Message-ID: <5416BCB0.30502@redhat.com> (raw)
In-Reply-To: <1410758605-29375-3-git-send-email-famz@redhat.com>
Il 15/09/2014 07:23, Fam Zheng ha scritto:
> SCSIRequest *sreq;
> size_t resp_size;
> enum SCSIXferMode mode;
> - QEMUIOVector resp_iov;
> union {
> VirtIOSCSICmdResp cmd;
> VirtIOSCSICtrlTMFResp tmf;
> @@ -68,23 +75,27 @@ static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
> static VirtIOSCSIReq *virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq)
> {
> VirtIOSCSIReq *req;
> - VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
> -
> - req = g_malloc0(sizeof(*req) + vs->cdb_size);
> + VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
> + const size_t zero_skip = offsetof(VirtIOSCSIReq, elem)
> + + sizeof(VirtQueueElement);
>
> + req = g_slice_alloc(sizeof(*req) + vs->cdb_size);
Looks good, but why do you need to zero the union? You only need to
zero sreq, resp_size and mode, don't you (and at this point, memset
becomes superfluous)?
Paolo
next prev parent reply other threads:[~2014-09-15 10:17 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-15 5:23 [Qemu-devel] [PATCH v2 0/2] virtio-scsi: Optimizing request allocation Fam Zheng
2014-09-15 5:23 ` [Qemu-devel] [PATCH v2 1/2] scsi: Optimize scsi_req_alloc Fam Zheng
2014-09-15 10:15 ` Paolo Bonzini
2014-09-15 5:23 ` [Qemu-devel] [PATCH v2 2/2] virtio-scsi: Optimize virtio_scsi_init_req Fam Zheng
2014-09-15 10:17 ` Paolo Bonzini [this message]
2014-09-16 7:16 ` Fam Zheng
2014-09-16 8:15 ` Paolo Bonzini
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