On Wed, Oct 14, 2009 at 04:43:57PM +0800, Peter Teoh wrote:
> In linux kernel, the SKB design is to facilitate the zerocopy
> processing of network packets. Does the concept likewise exists in
> the present Opensolaris?
>
> According to:
>
> http://opensolaris.org/os/community/networking/docs/dtrace_networking_cookbook/
>
> there is a zerocopy.d script to facilitate the analysis. Anyone
> provide me a copy of that?
Sure, I've attached a copy. However, there have been changes to the
code paths that the script instruments, so some tweaking might be
required.
> My preliminary analysis through probing in various API (like
> ip_tcp_input, ip_input etc) is that it is not zerocopy yet, is that
> correct?
Zero copy is supported and is used by sendfile(3ext).
Cheers,
Anders
#!/usr/sbin/dtrace -s
#pragma D option flowindent
/*
* TCP Zero Copy monitoring dscript.
*
* Code contributed by Alex Peng
*
* The author notes: " This script mointors TCP's ZeroCopy feature, shows what
happens
* at different components, e.g., STREAM head, TCP, IP (ill), mblk etc.".
*/
tcp_t *tcp;
conn_t *connp;
ire_t *ire;
ill_t *ill;
queue_t *q;
mblk_t *mp;
struct stdata *stp;
file_t *fp;
vnode_t *vp;
struct sonode *so;
fbt::tcp_zcopy_check:entry
{
trace(execname);
stack();
tcp = (tcp_t *)arg0;
printf("\n");
printf("tcp: \t%p\n", tcp);
printf("connp: \t%p\n", (conn_t *)tcp->tcp_connp);
printf("tcp->tcp_snd_zcopy_on: \t%d\n", tcp->tcp_snd_zcopy_on);
self->trace_zchck = 1;
}
fbt::tcp_zcopy_check:return
/self->trace_zchck/
{
printf("\n");
printf("zc_enabled: \t%d\n", arg1);
printf("tcp->tcp_snd_zcopy_on: \t%d\n", tcp->tcp_snd_zcopy_on);
}
fbt::snf_segmap:entry
/self->trace_zchck/
{
fp = (file_t *)arg0;
vp = (vnode_t *)fp->f_vnode;
stp = (stdata_t *)vp->v_stream;
/* trace(execname); */
printf("\nstp->sd_copyflag: \t%x\n", stp->sd_copyflag);
}
/*
fbt::sostream_direct:entry
/self->trace_zchck/
{
so = (struct sonode *)arg0;
stp = so->so_vnode->v_stream;
trace(execname);
printf("\nstp->sd_copyflag: \t%x\n", stp->sd_copyflag);
}
*/
fbt::kstrwritemp:entry
/self->trace_zchck/
{
mp = (mblk_t *)arg1;
trace(execname);
printf("\n");
printf("mblk2dblk dblk struioflag: \t");
printf("db->db_struioflag: \t%d\n", mp->b_datap->db_struioflag);
printf("msg lenth: \t%d\n", mp->b_wptr - mp->b_rptr);
}
fbt::tcp_send_data:entry
/self->trace_zchck/
{
trace(execname);
/* stack(); */
/* tcp = (tcp_t *)arg0; */
q = (queue_t *)arg1;
mp = (mblk_t *)arg2;
connp = tcp->tcp_connp;
stp = q->q_stream;
printf("\n");
printf("STREAM head copyflag \t");
printf("stp->sd_copyflag: \t%x\n", stp->sd_copyflag);
printf("tcp: \t%p\n", tcp);
printf("tcp->tcp_snd_zcopy_on: \t%d\n", tcp->tcp_snd_zcopy_on);
printf("tcp->tcp_snd_zcopy_aware: \t%d\n", tcp->tcp_snd_zcopy_aware);
printf("tcp->tcp_connp: \t%p\n", connp);
printf("\n");
}
fbt::ire_to_ill:entry
/self->trace_zchck/
{
ire = (ire_t *)arg0;
printf("\n");
printf("ire: \t%p\n", ire);
printf("\n");
}
fbt::ire_to_ill:return
/self->trace_zchck/
{
ill = (ill_t *)arg1;
printf("\n");
printf("ill: \t%p\n", ill);
printf("\n");
printf("ill_name: \t%s\n", stringof(ill->ill_name));
printf("ill_capabilities: \t%x\n", ill->ill_capabilities);
printf("ill_zerocopy_capab->version: \t%d\n",
ill->ill_zerocopy_capab->ill_zerocopy_version);
printf("ill_zerocopy_capab->flags: \t%d\n",
ill->ill_zerocopy_capab->ill_zerocopy_flags);
printf("\n");
}
fbt::tcp_send_data:return
/self->trace_zchck/
{
self->trace_zchck = 0;
}
fbt:sockfs::entry,
fbt:tcp::entry,
fbt:ip::entry,
fbt:hook::entry,
fbt:ipf::entry,
fbt:bge::entry
/self->trace_zchck/
{}
fbt:sockfs::return,
fbt:tcp::return,
fbt:ip::return,
fbt:hook::return,
fbt:ipf::return,
fbt:bge::return
/self->trace_zchck/
{
trace(arg1);
}
END
/self->trace_zchck/
{
self->trace_zchck = 0;
exit(0);
}
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