Stefan Manegold wrote:

On Sun, Jan 31, 2010 at 04:43:29PM +0000, Martin Kersten wrote:

...

Update of /cvsroot/monetdb/MonetDB/src/gdk In directory sfp-cvsdas-1.v30.ch3.sourceforge.com:/tmp/cvs-serv28035

Modified Files: Tag: Feb2010 gdk_storage.mx Log Message: A pity that the first code was not properly checked, because it did not even tried to force the preload by memory touching properly.

As per request (though admittedly belated ...):

nothing is too late and indeed this was the previous code. It could be that the BATs you touch will be filled, then the size is the option.

Wouldn't it be sufficient (and faster and less memory consuming) to preload

The total amount of memory consumed is controlled by the dataflow admission policy. See the respective check-ins last two weeks. Monitoring the run of Q10 shows that with the current setting we stay properly within the memory bounds most of the time.

only that part of the heaps that is indeed used (i.e., holds useful/relevant data) instead of preloading the whole (possibly consciously over-allocated) heaps?

I.e., replacing ...heap->size by ...heap->free

(as it was in the original code, only that the original code incorrecly assumed ...heap->free to be an absolute address instead of a relative byte offset ...)

original code incorrectly used b->hheap and b->theap, which also need to be preloaded upon need. Martin

Stefan

...

Index: gdk_storage.mx

RCS file: /cvsroot/monetdb/MonetDB/src/gdk/gdk_storage.mx,v retrieving revision 1.149.2.5 retrieving revision 1.149.2.6 diff -u -d -r1.149.2.5 -r1.149.2.6 --- gdk_storage.mx 31 Jan 2010 15:50:19 -0000 1.149.2.5 +++ gdk_storage.mx 31 Jan 2010 16:43:27 -0000 1.149.2.6 @@ -703,28 +703,32 @@ @c size_t BATpreload_(BAT *b) {

• size_t dummy = 0, *i;

• size_t dummy = 0, *i, *limit; size_t step = MT_pagesize()/sizeof(size_t); size_t pages = (size_t) (0.8 * MT_npages());

• if ( b->T->vheap && b->T->vheap->base ){

• IODEBUG THRprintf(GDKout,"#BATpreload(%s): T->vheap\n", BATgetId(b));
  

• for ( i = (size_t *) b->T->vheap->base; i < (size_t *) b->T->vheap->free  && pages > 0; i+= step, pages--)
  

• if ( b->T->vheap && b->T->vheap->base && pages){

• IODEBUG THRprintf(GDKout,"#BATpreloaded(%s): T->vheap\n", BATgetId(b));
  

• limit = (size_t *) (b->T->vheap->base + b->T->vheap->size);
  

• for ( i = (size_t *) b->T->vheap->base; i < limit  && pages > 0; i+= step, pages--)
  dummy += *i;
  

  }

• if ( b->H->vheap && b->H->vheap->base ){

• IODEBUG THRprintf(GDKout,"#BATpreload(%s): H->vheap\n", BATgetId(b));
  

• for ( i = (size_t *) b->H->vheap->base; i < (size_t *) b->H->vheap->free && pages > 0 ; i+= step, pages--)
  

• if ( b->T->heap.base && pages ){

• IODEBUG THRprintf(GDKout,"#BATpreload(%s): T->heap\n", BATgetId(b));
  

• limit = (size_t *) (b->T->heap.base + b->T->heap.size);
  

• for ( i = (size_t *) b->T->heap.base; i < limit && pages > 0; i+= step, pages--)
  dummy += *i;
  

  }

• if ( b->hheap && b->hheap->base ){

• IODEBUG THRprintf(GDKout,"#BATpreload(%s): hheap\n", BATgetId(b));
  

• for ( i = (size_t *) b->hheap->base; i <  (size_t *)b->hheap->free && pages > 0 ; i+= step, pages--)
  

• if ( b->H->heap.base && pages ){

• IODEBUG THRprintf(GDKout,"#BATpreload(%s): H->heap\n", BATgetId(b));
  

• limit = (size_t *) (b->H->heap.base + b->H->heap.size);
  

• for ( i = (size_t *) b->H->heap.base; i <  limit && pages > 0 ; i+= step, pages--)
  dummy += *i;
  

  }

• if ( b->theap && b->theap->base ){

• IODEBUG THRprintf(GDKout,"#BATpreload(%s): theap\n", BATgetId(b));
  

• for ( i = (size_t *) b->theap->base; i < (size_t *) b->theap->free  && pages > 0; i+= step, pages--)
  

• if ( b->H->vheap && b->H->vheap->base && pages ){

• IODEBUG THRprintf(GDKout,"#BATpreload(%s): H->vheap\n", BATgetId(b));
  

• limit = (size_t *) (b->H->vheap->base + b->H->vheap->size);
  

• for ( i = (size_t *) b->H->vheap->base; i < limit && pages > 0 ; i+= step, pages--)
  dummy += *i;
  

  } return dummy;

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