On Wed, Apr 17, 2013 at 11:35:49AM -0400, Vlad Yasevich wrote: > On 04/17/2013 11:27 AM, Neil Horman wrote: > >On Wed, Apr 17, 2013 at 11:26:21AM +0200, Daniel Borkmann wrote: > >>On 04/17/2013 10:43 AM, David Laight wrote: > >>>> __u32 outstanding_bytes; > >>>> > >>>>- /* Are we doing fast-rtx on this queue */ > >>>>- char fast_rtx; > >>>>- > >>>>- /* Corked? */ > >>>>- char cork; > >>>>- > >>>>- /* Is this structure empty? */ > >>>>- char empty; > >>>>+ __u8 fast_rtx:1, /* Are we doing fast-rtx on this queue */ > >>>>+ cork:1, /* Corked? */ > >>>>+ empty:1; /* Is this structure empty? */ > >>>> }; > >>> > >>>Use of bitfields just makes the code slower. > >>>The only real excuse for using them is to reduce the size > >>>of a structure that is allocated a lot. > >> > >>sctp_outq is _embedded_ into an sctp_association structure, which > >>has [size: 2280, cachelines: 36, members: 76]! A next step would be > >>to try to reorder its elements carefully and see if we can reduce > >>the size by filling some holes. > >Unrelated note: How did you get pahole to give you that information? For some > >reason pahole can never glean any useful information about struct > >sctp_association for me, despite having dwarf info embedded into the cu. > > > > pahole -C sctp_association <sctp object file> works for me. > > -vlad > Strange, that doesn't work for me, and the DW_TAG_structure_type entry is in place in the debug_info section (though interestingly no byte offsets are noted for any members). I'll have to look at that further. Thanks Neil > >Neil > > > >>-- > >>To unsubscribe from this list: send the line "unsubscribe linux-sctp" in > >>the body of a message to majordomo@xxxxxxxxxxxxxxx > >>More majordomo info at http://vger.kernel.org/majordomo-info.html > >> > >-- > >To unsubscribe from this list: send the line "unsubscribe linux-sctp" in > >the body of a message to majordomo@xxxxxxxxxxxxxxx > >More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-sctp" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
