Messages in this thread Patch in this message | | | Subject | Re: [PATCH 6/6] Use one zonelist that is filtered by nodemask | From | Lee Schermerhorn <> | Date | Tue, 20 Nov 2007 10:14:39 -0500 |
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On Tue, 2007-11-20 at 14:19 +0000, Mel Gorman wrote: > On (09/11/07 07:45), Christoph Lameter didst pronounce: > > On Fri, 9 Nov 2007, Mel Gorman wrote: > > > > > struct page * fastcall > > > __alloc_pages(gfp_t gfp_mask, unsigned int order, > > > struct zonelist *zonelist) > > > { > > > + /* > > > + * Use a temporary nodemask for __GFP_THISNODE allocations. If the > > > + * cost of allocating on the stack or the stack usage becomes > > > + * noticable, allocate the nodemasks per node at boot or compile time > > > + */ > > > + if (unlikely(gfp_mask & __GFP_THISNODE)) { > > > + nodemask_t nodemask; > > > > Hmmm.. This places a potentially big structure on the stack. nodemask can > > contain up to 1024 bits which means 128 bytes. Maybe keep an array of > > gfp_thisnode nodemasks (node_nodemask?) and use node_nodemask[nid]? > > Went back and revisited this. Allocating them at boot-time is below but > essentially it is a silly and it makes sense to just have two zonelists > where one of them is for __GFP_THISNODE. Implementation wise, this involves > dropping the last patch in the set and the overall result is still a reduction > in the number of zonelists.
Hi, Mel:
I'll try this out [n 24-rc2-mm1 or later]. I have a series with yet another rework of policy reference counting that will be easier/cleaner atop your series w/o the external zonelist hung off 'BIND policies. So, I'm hoping your series goes into -mm "real soon now".
Question: Just wondering why you didn't embed the '_THISNODE nodemask in the pgdat_t--initialized at boot/node-hot-add time? Perhaps under #ifdef CONFIG_NUMA. The size is known at build time, right? And wouldn't that be way smaller than an additional zonelist?
Lee
> > diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.24-rc2-mm1-040_use_one_zonelist/include/linux/gfp.h linux-2.6.24-rc2-mm1-045_use_static_nodemask/include/linux/gfp.h > --- linux-2.6.24-rc2-mm1-040_use_one_zonelist/include/linux/gfp.h 2007-11-19 19:27:15.000000000 +0000 > +++ linux-2.6.24-rc2-mm1-045_use_static_nodemask/include/linux/gfp.h 2007-11-19 19:28:55.000000000 +0000 > @@ -175,7 +175,6 @@ FASTCALL(__alloc_pages(gfp_t, unsigned i > extern struct page * > FASTCALL(__alloc_pages_nodemask(gfp_t, unsigned int, > struct zonelist *, nodemask_t *nodemask)); > -extern nodemask_t *nodemask_thisnode(int nid, nodemask_t *nodemask); > > static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask, > unsigned int order) > @@ -187,13 +186,10 @@ static inline struct page *alloc_pages_n > if (nid < 0) > nid = numa_node_id(); > > - /* Use a temporary nodemask for __GFP_THISNODE allocations */ > if (unlikely(gfp_mask & __GFP_THISNODE)) { > - nodemask_t nodemask; > - > return __alloc_pages_nodemask(gfp_mask, order, > node_zonelist(nid), > - nodemask_thisnode(nid, &nodemask)); > + NODE_DATA(nid)->nodemask_thisnode); > } > > return __alloc_pages(gfp_mask, order, node_zonelist(nid)); > diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.24-rc2-mm1-040_use_one_zonelist/include/linux/mmzone.h linux-2.6.24-rc2-mm1-045_use_static_nodemask/include/linux/mmzone.h > --- linux-2.6.24-rc2-mm1-040_use_one_zonelist/include/linux/mmzone.h 2007-11-19 19:27:15.000000000 +0000 > +++ linux-2.6.24-rc2-mm1-045_use_static_nodemask/include/linux/mmzone.h 2007-11-19 19:28:55.000000000 +0000 > @@ -519,6 +519,9 @@ typedef struct pglist_data { > struct zone node_zones[MAX_NR_ZONES]; > struct zonelist node_zonelist; > int nr_zones; > + > + /* nodemask suitable for __GFP_THISNODE */ > + nodemask_t *nodemask_thisnode; > #ifdef CONFIG_FLAT_NODE_MEM_MAP > struct page *node_mem_map; > #endif > diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.24-rc2-mm1-040_use_one_zonelist/mm/page_alloc.c linux-2.6.24-rc2-mm1-045_use_static_nodemask/mm/page_alloc.c > --- linux-2.6.24-rc2-mm1-040_use_one_zonelist/mm/page_alloc.c 2007-11-19 19:27:15.000000000 +0000 > +++ linux-2.6.24-rc2-mm1-045_use_static_nodemask/mm/page_alloc.c 2007-11-19 19:28:55.000000000 +0000 > @@ -1695,28 +1695,36 @@ got_pg: > } > > /* Creates a nodemask suitable for GFP_THISNODE allocations */ > -nodemask_t *nodemask_thisnode(int nid, nodemask_t *nodemask) > +static inline void alloc_node_nodemask_thisnode(pg_data_t *pgdat) > { > - nodes_clear(*nodemask); > - node_set(nid, *nodemask); > + nodemask_t *nodemask_thisnode; > > - return nodemask; > + /* Only a machine with multiple nodes needs the nodemask */ > + if (!NUMA_BUILD || num_online_nodes() == 1) > + return; > + > + /* Allocate the nodemask. Serious if it fails, but not world ending */ > + nodemask_thisnode = alloc_bootmem_node(pgdat, sizeof(nodemask_t)); > + if (!nodemask_thisnode) { > + printk(KERN_WARNING > + "thisnode nodemask allocation failed." > + "There may be sub-optimal NUMA placement.\n"); > + return; > + } > + > + /* Initialise the nodemask to only cover the current node */ > + nodes_clear(*nodemask_thisnode); > + node_set(pgdat->node_id, *nodemask_thisnode); > + pgdat->nodemask_thisnode = nodemask_thisnode; > } > > struct page * fastcall > __alloc_pages(gfp_t gfp_mask, unsigned int order, > struct zonelist *zonelist) > { > - /* > - * Use a temporary nodemask for __GFP_THISNODE allocations. If the > - * cost of allocating on the stack or the stack usage becomes > - * noticable, allocate the nodemasks per node at boot or compile time > - */ > if (unlikely(gfp_mask & __GFP_THISNODE)) { > - nodemask_t nodemask; > - > - return __alloc_pages_internal(gfp_mask, order, > - zonelist, nodemask_thisnode(numa_node_id(), &nodemask)); > + return __alloc_pages_internal(gfp_mask, order, zonelist, > + NODE_DATA(numa_node_id())->nodemask_thisnode); > } > > return __alloc_pages_internal(gfp_mask, order, zonelist, NULL); > @@ -3501,6 +3509,7 @@ void __meminit free_area_init_node(int n > calculate_node_totalpages(pgdat, zones_size, zholes_size); > > alloc_node_mem_map(pgdat); > + alloc_node_nodemask_thisnode(pgdat); > > free_area_init_core(pgdat, zones_size, zholes_size); > } >
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