| Message ID | bb0ee76c-78ac-b75b-b32d-8c94d881f7d6@cybernetics.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mpt3sas and dmapool scalability | expand |
On Mon, Nov 12, 2018 at 10:45:58AM -0500, Tony Battersby wrote: > +++ linux/mm/dmapool.c 2018-08-06 17:52:53.000000000 -0400 > @@ -61,6 +61,7 @@ struct dma_pool { /* the pool */ > struct device *dev; > unsigned int allocation; > unsigned int boundary; > + unsigned int blks_per_alloc; > char name[32]; > struct list_head pools; > }; This one I'm not totally happy with. You're storing this value when it could be easily calculated each time through the show_pools() code. I appreciate this is a topic where reasonable people might have different opinions about which solution is preferable. > @@ -182,6 +182,9 @@ struct dma_pool *dma_pool_create(const c > retval->size = size; > retval->boundary = boundary; > retval->allocation = allocation; > + retval->blks_per_alloc = > + (allocation / boundary) * (boundary / size) + > + (allocation % boundary) / size; > > INIT_LIST_HEAD(&retval->pools); > >
--- linux/mm/dmapool.c.orig 2018-08-06 17:48:54.000000000 -0400 +++ linux/mm/dmapool.c 2018-08-06 17:52:53.000000000 -0400 @@ -61,6 +61,7 @@ struct dma_pool { /* the pool */ struct device *dev; unsigned int allocation; unsigned int boundary; + unsigned int blks_per_alloc; char name[32]; struct list_head pools; }; @@ -105,8 +106,7 @@ show_pools(struct device *dev, struct de /* per-pool info, no real statistics yet */ temp = scnprintf(next, size, "%-16s %4zu %4zu %4u %2u\n", pool->name, blocks, - (size_t) pages * - (pool->allocation / pool->size), + (size_t) pages * pool->blks_per_alloc, pool->size, pages); size -= temp; next += temp; @@ -182,6 +182,9 @@ struct dma_pool *dma_pool_create(const c retval->size = size; retval->boundary = boundary; retval->allocation = allocation; + retval->blks_per_alloc = + (allocation / boundary) * (boundary / size) + + (allocation % boundary) / size; INIT_LIST_HEAD(&retval->pools);
The "total number of blocks in pool" debug statistic currently does not take the boundary value into account, so it diverges from the "total number of blocks in use" statistic when a boundary is in effect. Add a calculation for the number of blocks per allocation that takes the boundary into account, and use it to replace the inaccurate calculation. Signed-off-by: Tony Battersby <tonyb@cybernetics.com> --- This depends on patch #1 "dmapool: fix boundary comparison" for the calculated blks_per_alloc value to be correct. The added blks_per_alloc value will also be used in the next patch.