[PATCH 0/7] printing: improve printcap update CPU usage

Jeremy Allison jra at samba.org
Mon Aug 4 16:31:55 MDT 2014

On Tue, Aug 05, 2014 at 12:26:20AM +0200, David Disseldorp wrote:
> On Mon,  4 Aug 2014 15:58:00 +0200, David Disseldorp wrote:
> > This patch-set attempts to address bug 10652: Samba consumes a lot of
> > CPU when re-reading printcap info.
> > 
> > It does so with the following changes to the printcap update procedure:
> > - Use traverse_read for printer list share updates, instead of exclusive
> >   (write locked) traversals. This significantly reduces printer_list.tdb
> >   lock contention.
> > - As suggested by Volker, reload per-client smbd printer share
> >   inventories on client enumeration, rather than immediately after every
> >   printer list update.
> >   - If enumeration is requested but the printer list has not changed,
> >     then skip the printer share inventory update.
> Looks like one further change is needed here to handle clients that do
> not enumerate printers prior to open, such as cupsaddsmb.

While you are going around one more time on this, can you
move the function delete_and_reload_printers_full() from
source3/smbd/server_reload.c -> source3/printing/queue_process.c
and make it static ? Also, if you could eliminate the duplicate
definitions of snum_is_shared_printer() in source3/rpc_server/spoolss/srv_spoolss_nt.c
and in source3/smbd/server_reload.c that would be great also :-).

Sorry for asking for more, but these extra things would
really help clean up the printing code somewhat, and make
it clearer what's being done in the background process.



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