For shared mappings, the pointer to the hugetlb_cgroup to uncharge lives in the resv_map entries, in file_region->reservation_counter.
After a call to region_chg, we charge the approprate hugetlb_cgroup, and if successful, we pass on the hugetlb_cgroup info to a follow up region_add call. When a file_region entry is added to the resv_map via region_add, we put the pointer to that cgroup in file_region->reservation_counter. If charging doesn't succeed, we report the error to the caller, so that the kernel fails the reservation.
On region_del, which is when the hugetlb memory is unreserved, we also uncharge the file_region->reservation_counter.
Signed-off-by: Mina Almasry almasrymina@google.com
---
Changes in v12: - Removed per-file-region pages_per_hpage field. - Rearranged some function params. - Fixed goto out_put_pages error condition.
Changes in v11: - Created new function, hugetlb_cgroup_uncharge_file_region to clean up some #ifdefs. - Moved file_region definition to hugetlb.h. - Added copy_hugetlb_cgroup_uncharge_info function to clean up more #ifdefs in the middle of hugetlb code.
Changes in v10: - Deleted duplicated code snippet.
Changes in V9: - Updated for hugetlb reservation repareting.
--- include/linux/hugetlb.h | 35 ++++++++ include/linux/hugetlb_cgroup.h | 10 +++ mm/hugetlb.c | 148 +++++++++++++++++++++------------ mm/hugetlb_cgroup.c | 15 ++++ 4 files changed, 154 insertions(+), 54 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 5491932ea5758..50480d16bd334 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -57,6 +57,41 @@ struct resv_map { struct cgroup_subsys_state *css; #endif }; + +/* + * Region tracking -- allows tracking of reservations and instantiated pages + * across the pages in a mapping. + * + * The region data structures are embedded into a resv_map and protected + * by a resv_map's lock. The set of regions within the resv_map represent + * reservations for huge pages, or huge pages that have already been + * instantiated within the map. The from and to elements are huge page + * indicies into the associated mapping. from indicates the starting index + * of the region. to represents the first index past the end of the region. + * + * For example, a file region structure with from == 0 and to == 4 represents + * four huge pages in a mapping. It is important to note that the to element + * represents the first element past the end of the region. This is used in + * arithmetic as 4(to) - 0(from) = 4 huge pages in the region. + * + * Interval notation of the form [from, to) will be used to indicate that + * the endpoint from is inclusive and to is exclusive. + */ +struct file_region { + struct list_head link; + long from; + long to; +#ifdef CONFIG_CGROUP_HUGETLB + /* + * On shared mappings, each reserved region appears as a struct + * file_region in resv_map. These fields hold the info needed to + * uncharge each reservation. + */ + struct page_counter *reservation_counter; + struct cgroup_subsys_state *css; +#endif +}; + extern struct resv_map *resv_map_alloc(void); void resv_map_release(struct kref *ref);
diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h index 9974817eb995f..a09d4164ba910 100644 --- a/include/linux/hugetlb_cgroup.h +++ b/include/linux/hugetlb_cgroup.h @@ -133,11 +133,21 @@ extern void hugetlb_cgroup_uncharge_counter(struct resv_map *resv, unsigned long start, unsigned long end);
+extern void hugetlb_cgroup_uncharge_file_region(struct resv_map *resv, + struct file_region *rg, + unsigned long nr_pages); + extern void hugetlb_cgroup_file_init(void) __init; extern void hugetlb_cgroup_migrate(struct page *oldhpage, struct page *newhpage);
#else +static inline void hugetlb_cgroup_uncharge_file_region(struct resv_map *resv, + struct file_region *rg, + unsigned long nr_pages) +{ +} + static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page) { return NULL; diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 57739e1aedeca..a9171c3cbed6b 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -220,31 +220,6 @@ static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma) return subpool_inode(file_inode(vma->vm_file)); }
-/* - * Region tracking -- allows tracking of reservations and instantiated pages - * across the pages in a mapping. - * - * The region data structures are embedded into a resv_map and protected - * by a resv_map's lock. The set of regions within the resv_map represent - * reservations for huge pages, or huge pages that have already been - * instantiated within the map. The from and to elements are huge page - * indicies into the associated mapping. from indicates the starting index - * of the region. to represents the first index past the end of the region. - * - * For example, a file region structure with from == 0 and to == 4 represents - * four huge pages in a mapping. It is important to note that the to element - * represents the first element past the end of the region. This is used in - * arithmetic as 4(to) - 0(from) = 4 huge pages in the region. - * - * Interval notation of the form [from, to) will be used to indicate that - * the endpoint from is inclusive and to is exclusive. - */ -struct file_region { - struct list_head link; - long from; - long to; -}; - /* Helper that removes a struct file_region from the resv_map cache and returns * it for use. */ @@ -266,6 +241,41 @@ get_file_region_entry_from_cache(struct resv_map *resv, long from, long to) return nrg; }
+static void copy_hugetlb_cgroup_uncharge_info(struct file_region *nrg, + struct file_region *rg) +{ +#ifdef CONFIG_CGROUP_HUGETLB + nrg->reservation_counter = rg->reservation_counter; + nrg->css = rg->css; + if (rg->css) + css_get(rg->css); +#endif +} + +/* Helper that records hugetlb_cgroup uncharge info. */ +static void record_hugetlb_cgroup_uncharge_info(struct hugetlb_cgroup *h_cg, + struct hstate *h, + struct resv_map *resv, + struct file_region *nrg) +{ +#ifdef CONFIG_CGROUP_HUGETLB + if (h_cg) { + nrg->reservation_counter = + &h_cg->rsvd_hugepage[hstate_index(h)]; + nrg->css = &h_cg->css; + if (!resv->pages_per_hpage) + resv->pages_per_hpage = pages_per_huge_page(h); + /* pages_per_hpage should be the same for all entries in + * a resv_map. + */ + VM_BUG_ON(resv->pages_per_hpage != pages_per_huge_page(h)); + } else { + nrg->reservation_counter = NULL; + nrg->css = NULL; + } +#endif +} + /* 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. If regions_needed != NULL and count_only == true, then regions_needed @@ -273,7 +283,9 @@ get_file_region_entry_from_cache(struct resv_map *resv, long from, long to) * add the regions for this range. */ static long add_reservation_in_range(struct resv_map *resv, long f, long t, - long *regions_needed, bool count_only) + struct hugetlb_cgroup *h_cg, + struct hstate *h, long *regions_needed, + bool count_only) { long add = 0; struct list_head *head = &resv->regions; @@ -312,6 +324,8 @@ static long add_reservation_in_range(struct resv_map *resv, long f, long t, if (!count_only) { nrg = get_file_region_entry_from_cache( resv, last_accounted_offset, rg->from); + record_hugetlb_cgroup_uncharge_info(h_cg, h, + resv, nrg); list_add(&nrg->link, rg->link.prev); } else if (regions_needed) *regions_needed += 1; @@ -328,6 +342,7 @@ static long add_reservation_in_range(struct resv_map *resv, long f, long t, if (!count_only) { nrg = get_file_region_entry_from_cache( resv, last_accounted_offset, t); + record_hugetlb_cgroup_uncharge_info(h_cg, h, resv, nrg); list_add(&nrg->link, rg->link.prev); } else if (regions_needed) *regions_needed += 1; @@ -355,7 +370,8 @@ static long add_reservation_in_range(struct resv_map *resv, long f, long t, * 1 page will only require at most 1 entry. */ static long region_add(struct resv_map *resv, long f, long t, - long in_regions_needed) + long in_regions_needed, struct hstate *h, + struct hugetlb_cgroup *h_cg) { long add = 0, actual_regions_needed = 0, i = 0; struct file_region *trg = NULL, *rg = NULL; @@ -367,7 +383,8 @@ static long region_add(struct resv_map *resv, long f, long t, retry:
/* Count how many regions are actually needed to execute this add. */ - add_reservation_in_range(resv, f, t, &actual_regions_needed, true); + add_reservation_in_range(resv, f, t, NULL, NULL, &actual_regions_needed, + true);
/* * Check for sufficient descriptors in the cache to accommodate @@ -405,7 +422,7 @@ static long region_add(struct resv_map *resv, long f, long t, goto retry; }
- add = add_reservation_in_range(resv, f, t, NULL, false); + add = add_reservation_in_range(resv, f, t, h_cg, h, NULL, false);
resv->adds_in_progress -= in_regions_needed;
@@ -453,7 +470,8 @@ static long region_chg(struct resv_map *resv, long f, long t, spin_lock(&resv->lock);
/* Count how many hugepages in this range are NOT respresented. */ - chg = add_reservation_in_range(resv, f, t, out_regions_needed, true); + chg = add_reservation_in_range(resv, f, t, NULL, NULL, + out_regions_needed, true);
if (*out_regions_needed == 0) *out_regions_needed = 1; @@ -589,11 +607,17 @@ static long region_del(struct resv_map *resv, long f, long t) /* New entry for end of split region */ nrg->from = t; nrg->to = rg->to; + + copy_hugetlb_cgroup_uncharge_info(nrg, rg); + INIT_LIST_HEAD(&nrg->link);
/* Original entry is trimmed */ rg->to = f;
+ hugetlb_cgroup_uncharge_file_region( + resv, rg, nrg->to - nrg->from); + list_add(&nrg->link, &rg->link); nrg = NULL; break; @@ -601,6 +625,8 @@ static long region_del(struct resv_map *resv, long f, long t)
if (f <= rg->from && t >= rg->to) { /* Remove entire region */ del += rg->to - rg->from; + hugetlb_cgroup_uncharge_file_region(resv, rg, + rg->to - rg->from); list_del(&rg->link); kfree(rg); continue; @@ -609,9 +635,15 @@ static long region_del(struct resv_map *resv, long f, long t) if (f <= rg->from) { /* Trim beginning of region */ del += t - rg->from; rg->from = t; + + hugetlb_cgroup_uncharge_file_region(resv, rg, + t - rg->from); } else { /* Trim end of region */ del += rg->to - f; rg->to = f; + + hugetlb_cgroup_uncharge_file_region(resv, rg, + rg->to - f); } }
@@ -2018,7 +2050,7 @@ static long __vma_reservation_common(struct hstate *h, VM_BUG_ON(dummy_out_regions_needed != 1); break; case VMA_COMMIT_RESV: - ret = region_add(resv, idx, idx + 1, 1); + ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); /* region_add calls of range 1 should never fail. */ VM_BUG_ON(ret < 0); break; @@ -2028,7 +2060,7 @@ static long __vma_reservation_common(struct hstate *h, break; case VMA_ADD_RESV: if (vma->vm_flags & VM_MAYSHARE) { - ret = region_add(resv, idx, idx + 1, 1); + ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); /* region_add calls of range 1 should never fail. */ VM_BUG_ON(ret < 0); } else { @@ -4686,7 +4718,7 @@ int hugetlb_reserve_pages(struct inode *inode, struct hstate *h = hstate_inode(inode); struct hugepage_subpool *spool = subpool_inode(inode); struct resv_map *resv_map; - struct hugetlb_cgroup *h_cg; + struct hugetlb_cgroup *h_cg = NULL; long gbl_reserve, regions_needed = 0;
/* This should never happen */ @@ -4727,19 +4759,6 @@ int hugetlb_reserve_pages(struct inode *inode,
chg = to - from;
- if (hugetlb_cgroup_charge_cgroup_rsvd( - hstate_index(h), chg * pages_per_huge_page(h), - &h_cg)) { - kref_put(&resv_map->refs, resv_map_release); - return -ENOMEM; - } - - /* - * Since this branch handles private mappings, we attach the - * counter to uncharge for this reservation off resv_map. - */ - resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, h_cg, h); - set_vma_resv_map(vma, resv_map); set_vma_resv_flags(vma, HPAGE_RESV_OWNER); } @@ -4749,6 +4768,21 @@ int hugetlb_reserve_pages(struct inode *inode, goto out_err; }
+ ret = hugetlb_cgroup_charge_cgroup_rsvd( + hstate_index(h), chg * pages_per_huge_page(h), &h_cg); + + if (ret < 0) { + ret = -ENOMEM; + goto out_err; + } + + if (vma && !(vma->vm_flags & VM_MAYSHARE) && h_cg) { + /* For private mappings, the hugetlb_cgroup uncharge info hangs + * of the resv_map. + */ + resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, h_cg, h); + } + /* * There must be enough pages in the subpool for the mapping. If * the subpool has a minimum size, there may be some global @@ -4757,7 +4791,7 @@ int hugetlb_reserve_pages(struct inode *inode, gbl_reserve = hugepage_subpool_get_pages(spool, chg); if (gbl_reserve < 0) { ret = -ENOSPC; - goto out_err; + goto out_uncharge_cgroup; }
/* @@ -4766,9 +4800,7 @@ int hugetlb_reserve_pages(struct inode *inode, */ ret = hugetlb_acct_memory(h, gbl_reserve); if (ret < 0) { - /* put back original number of pages, chg */ - (void)hugepage_subpool_put_pages(spool, chg); - goto out_err; + goto out_put_pages; }
/* @@ -4783,13 +4815,11 @@ int hugetlb_reserve_pages(struct inode *inode, * else has to be done for private mappings here */ if (!vma || vma->vm_flags & VM_MAYSHARE) { - add = region_add(resv_map, from, to, regions_needed); + add = region_add(resv_map, from, to, regions_needed, h, h_cg);
if (unlikely(add < 0)) { hugetlb_acct_memory(h, -gbl_reserve); - /* put back original number of pages, chg */ - (void)hugepage_subpool_put_pages(spool, chg); - goto out_err; + goto out_put_pages; } else if (unlikely(chg > add)) { /* * pages in this range were added to the reserve @@ -4800,12 +4830,22 @@ int hugetlb_reserve_pages(struct inode *inode, */ long rsv_adjust;
+ hugetlb_cgroup_uncharge_cgroup_rsvd( + hstate_index(h), + (chg - add) * pages_per_huge_page(h), h_cg); + rsv_adjust = hugepage_subpool_put_pages(spool, chg - add); hugetlb_acct_memory(h, -rsv_adjust); } } return 0; +out_put_pages: + /* put back original number of pages, chg */ + (void)hugepage_subpool_put_pages(spool, chg); +out_uncharge_cgroup: + hugetlb_cgroup_uncharge_cgroup_rsvd(hstate_index(h), + chg * pages_per_huge_page(h), h_cg); out_err: if (!vma || vma->vm_flags & VM_MAYSHARE) /* Only call region_abort if the region_chg succeeded but the diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c index bae7bf6b8372f..ad777fecad28a 100644 --- a/mm/hugetlb_cgroup.c +++ b/mm/hugetlb_cgroup.c @@ -392,6 +392,21 @@ void hugetlb_cgroup_uncharge_counter(struct resv_map *resv, unsigned long start, css_put(resv->css); }
+void hugetlb_cgroup_uncharge_file_region(struct resv_map *resv, + struct file_region *rg, + unsigned long nr_pages) +{ + if (hugetlb_cgroup_disabled() || !resv || !rg || !nr_pages) + return; + + if (rg->reservation_counter && resv->pages_per_hpage && nr_pages > 0 && + !resv->reservation_counter) { + page_counter_uncharge(rg->reservation_counter, + nr_pages * resv->pages_per_hpage); + css_put(rg->css); + } +} + enum { RES_USAGE, RES_RSVD_USAGE, -- 2.25.0.225.g125e21ebc7-goog