Re: initializing shared memory

Posted in 1996

"Malcolm Weallans" — Thu, 26 Sep 1996 18:17:30 GMT — source: Informix-list mailing list archive (1991-1998)

David Williams wrote: > In article <Dy5noo.CsH@cix.compulink.co.uk>, "\\"Malcolm Weallans\\"" > <onlinedbc@cix.compulink.co.uk> writes > >> Gene Terry Sanford <tsanford@csti-md.com> wrote: > >> > >> :We are runnning informix 4.1 on SCO OpenSever 5.02. > >> :When we run tbinit to initialize shared memory we get > >> :the following error: > >> > >> : tbinit: shmat[EINVAL][22]: shared memory base address > >> : illegal using 0x80480000, needs 0x80000000 > >> : tbinit: fatal error in shared memory creation. > >> > >> :Our tbconfig file has SHMBASE = 0x80400000 > >> :Anyone have any idea what the problem is. It sounds like the > >> :shared memory base address for SCO needs to be changed. > >Have you tried modifying SHMBASE to Ox80000000? > > > >I have installed a number of SCO UNIX systems at different levels and > >found that to be necessary. But don't ask me why? > > > > > >Malcolm Weallans > >Online Database Consultancy > >Phone 01628-72154 > >Fax 01628-37463 > >CIX - onlinedbc > > It is the address that each VP uses to attach the first segment of > shared memory to it's own virtual address space. That is the address to > which it maps the first segment of shared memory. This needs to be set > such that is does not collide with > > a) Text segments which store code. > b) Data segments which store static/global segments > c) The stack segment (which can grow with the stack as nested > function are called). > d) Other data segments where the heap is stored which grow as memory > is malloc'ed. > > Different UNIX's map a)-d) at different address and so different > SHMBASE's are needed to avoid collisions of memory segments. > > Note some UNIX's support a value of 0 which means the UNIX kernel will > choose the correct value automatically. Clearly SCO is not one of > those. > > -- > David Williams I would point out that the user is using 4.1 which does not have VPs. My answer still stands. Sorry David. Malcolm Weallans Online Database Consultancy Phone 01628-72154 Fax 01628-37463 CIX - onlinedbc