Re: sdirno type?

Fine by me.

Note: in the long term we should be able to get rid of all those _status
bits from the StoreEntry. In theory it should be possible to move all of
them to the MemObject as active StoreObject's without a MemObject is
pretty much all of the same kind (plain cached object).

Regards
Henrik

Andres Kroonmaa wrote:
>
> On 4 Oct 2001, at 20:50, Henrik Nordstrom <hno@squid-cache.org> wrote:
>
> > Adrian Chadd wrote:
> >
> > > I've run my private test squids with the sdirno set to a char
> > > rather than an int. Things seem to run quite fine with the patch.
> > > Now, the storeentry has got an explicit bit size but I still
> > > think it'll be a good thing to get out of the way now.
> > >
> > > What do people think?
> >
> > I have expressed my opinion before. Still share the same view.
> >
> > Any change that further increases the size of StoreEntry modulo 4 on
> > Intel or Alpha is banned from Suqid-2.5. Period. For the next cycle of
> > HEAD such changes is fine.
> >
> > The size of the sdirno field is purely a exercise in memory usage. From
> > a stability point of view there is very little to say except that parts
> > of the code may expect it to be signed so a unqualified char type is
> > most likely a bad choice.
>
> struct _StoreEntry {
> hash_link hash; /* must be first */
> MemObject *mem_obj;
> RemovalPolicyNode repl;
> time_t timestamp;
> time_t lastref;
> time_t expires;
> time_t lastmod;
> size_t swap_file_sz;
> - sfileno swap_filen:25;
> - sdirno swap_dirn:7;
> + sfileno swap_filen;
> u_short refcount;
> u_short flags;
> u_short lock_count; /* Assume < 65536! */
> + sdirno swap_dirn:4;
> mem_status_t mem_status:3;
> ping_status_t ping_status:3;
> store_status_t store_status:3;
> swap_status_t swap_status:3;
> };
>
> Such layout keeps us at 48 bytes/sentry, the only limitation is
> max 16 sdirs. Is it acceptable compromise?
> I wonder how many people need more than that number of sdirs?
> Perhaps make this compiletime option. I understand that 32bit
> sfileno is currently requirement for using coss best.
>
> ------------------------------------
> Andres Kroonmaa <andre@online.ee>
> CTO, Microlink Online
> Tel: 6501 731, Fax: 6501 725
> Pärnu mnt. 158, Tallinn,
> 11317 Estonia
Received on Thu Oct 04 2001 - 13:47:03 MDT