From: Mina Almasry <almasrymina@xxxxxxxxxx> Subject: hugetlb: remove duplicated code Remove duplicated code between region_chg and region_add, and refactor it into a common function, add_reservation_in_range. This is mostly done because there is a follow up change in another series that disables region coalescing in region_add, and I want to make that change in one place only. It should improve maintainability anyway on its own. [akpm@xxxxxxxxxxxxxxxxxxxx: coding style fixes] Link: http://lkml.kernel.org/r/20190919200428.188797-3-almasrymina@xxxxxxxxxx Signed-off-by: Mina Almasry <almasrymina@xxxxxxxxxx> Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Greg Thelen <gthelen@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/hugetlb.c | 119 +++++++++++++++++++++++-------------------------- 1 file changed, 57 insertions(+), 62 deletions(-) --- a/mm/hugetlb.c~hugetlb-remove-duplicated-code +++ a/mm/hugetlb.c @@ -244,6 +244,60 @@ struct file_region { long to; }; +/* Must be called with resv->lock held. Calling this with count_only == true + * will count the number of pages to be added but will not modify the linked + * list. + */ +static long add_reservation_in_range(struct resv_map *resv, long f, long t, + bool count_only) +{ + long chg = 0; + struct list_head *head = &resv->regions; + struct file_region *rg = NULL, *trg = NULL, *nrg = NULL; + + /* Locate the region we are before or in. */ + list_for_each_entry(rg, head, link) + if (f <= rg->to) + break; + + /* Round our left edge to the current segment if it encloses us. */ + if (f > rg->from) + f = rg->from; + + chg = t - f; + + /* Check for and consume any regions we now overlap with. */ + nrg = rg; + list_for_each_entry_safe(rg, trg, rg->link.prev, link) { + if (&rg->link == head) + break; + if (rg->from > t) + break; + + /* We overlap with this area, if it extends further than + * us then we must extend ourselves. Account for its + * existing reservation. + */ + if (rg->to > t) { + chg += rg->to - t; + t = rg->to; + } + chg -= rg->to - rg->from; + + if (!count_only && rg != nrg) { + list_del(&rg->link); + kfree(rg); + } + } + + if (!count_only) { + nrg->from = f; + nrg->to = t; + } + + return chg; +} + /* * Add the huge page range represented by [f, t) to the reserve * map. Existing regions will be expanded to accommodate the specified @@ -257,7 +311,7 @@ struct file_region { static long region_add(struct resv_map *resv, long f, long t) { struct list_head *head = &resv->regions; - struct file_region *rg, *nrg, *trg; + struct file_region *rg, *nrg; long add = 0; spin_lock(&resv->lock); @@ -287,38 +341,7 @@ static long region_add(struct resv_map * goto out_locked; } - /* Round our left edge to the current segment if it encloses us. */ - if (f > rg->from) - f = rg->from; - - /* Check for and consume any regions we now overlap with. */ - nrg = rg; - list_for_each_entry_safe(rg, trg, rg->link.prev, link) { - if (&rg->link == head) - break; - if (rg->from > t) - break; - - /* If this area reaches higher then extend our area to - * include it completely. If this is not the first area - * which we intend to reuse, free it. */ - if (rg->to > t) - t = rg->to; - if (rg != nrg) { - /* Decrement return value by the deleted range. - * Another range will span this area so that by - * end of routine add will be >= zero - */ - add -= (rg->to - rg->from); - list_del(&rg->link); - kfree(rg); - } - } - - add += (nrg->from - f); /* Added to beginning of region */ - nrg->from = f; - add += t - nrg->to; /* Added to end of region */ - nrg->to = t; + add = add_reservation_in_range(resv, f, t, false); out_locked: resv->adds_in_progress--; @@ -345,8 +368,6 @@ out_locked: */ static long region_chg(struct resv_map *resv, long f, long t) { - struct list_head *head = &resv->regions; - struct file_region *rg; long chg = 0; spin_lock(&resv->lock); @@ -375,34 +396,8 @@ retry_locked: goto retry_locked; } - /* Locate the region we are before or in. */ - list_for_each_entry(rg, head, link) - if (f <= rg->to) - break; - - /* Round our left edge to the current segment if it encloses us. */ - if (f > rg->from) - f = rg->from; - chg = t - f; - - /* Check for and consume any regions we now overlap with. */ - list_for_each_entry(rg, rg->link.prev, link) { - if (&rg->link == head) - break; - if (rg->from > t) - goto out; - - /* We overlap with this area, if it extends further than - * us then we must extend ourselves. Account for its - * existing reservation. */ - if (rg->to > t) { - chg += rg->to - t; - t = rg->to; - } - chg -= rg->to - rg->from; - } + chg = add_reservation_in_range(resv, f, t, true); -out: spin_unlock(&resv->lock); return chg; } _
