| Message ID | 20201211202140.396852-5-pasha.tatashin@soleen.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | prohibit pinning pages in ZONE_MOVABLE | expand |
On Fri 11-12-20 15:21:38, Pavel Tatashin wrote: [...] > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index c2dea9ad0e98..4d8e7f801c66 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -3802,16 +3802,12 @@ alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask) > return alloc_flags; > } > > -static inline unsigned int current_alloc_flags(gfp_t gfp_mask, > - unsigned int alloc_flags) > +static inline unsigned int cma_alloc_flags(gfp_t gfp_mask, > + unsigned int alloc_flags) Do you have any strong reason to rename? Even though the current implementation only does something for cma I do not think this is all that important. The naming nicely fits with current_gfp_context so I would stick with it. Other than that the patch looks reasonable. I would just add a comment explaining that current_alloc_flags should be called _after_ current_gfp_context because that one might change the gfp_mask. With that addressed, feel free to add Acked-by: Michal Hocko <mhocko@suse.com>
On Mon, Dec 14, 2020 at 9:17 AM Michal Hocko <mhocko@suse.com> wrote: > > On Fri 11-12-20 15:21:38, Pavel Tatashin wrote: > [...] > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > > index c2dea9ad0e98..4d8e7f801c66 100644 > > --- a/mm/page_alloc.c > > +++ b/mm/page_alloc.c > > @@ -3802,16 +3802,12 @@ alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask) > > return alloc_flags; > > } > > > > -static inline unsigned int current_alloc_flags(gfp_t gfp_mask, > > - unsigned int alloc_flags) > > +static inline unsigned int cma_alloc_flags(gfp_t gfp_mask, > > + unsigned int alloc_flags) > > Do you have any strong reason to rename? Even though the current Yes :) > implementation only does something for cma I do not think this is all > that important. The naming nicely fits with current_gfp_context so I > would stick with it. I am renaming because current->flags is removed from this function, therefore keeping the name becomes misleading. This function only addresses cma flag check without looking at the thread local state now. > > Other than that the patch looks reasonable. I would just add a comment > explaining that current_alloc_flags should be called _after_ > current_gfp_context because that one might change the gfp_mask. Thanks, I will add it. > > With that addressed, feel free to add > Acked-by: Michal Hocko <mhocko@suse.com> Thank you, Pasha
On Tue 15-12-20 00:24:30, Pavel Tatashin wrote: > On Mon, Dec 14, 2020 at 9:17 AM Michal Hocko <mhocko@suse.com> wrote: > > > > On Fri 11-12-20 15:21:38, Pavel Tatashin wrote: > > [...] > > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > > > index c2dea9ad0e98..4d8e7f801c66 100644 > > > --- a/mm/page_alloc.c > > > +++ b/mm/page_alloc.c > > > @@ -3802,16 +3802,12 @@ alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask) > > > return alloc_flags; > > > } > > > > > > -static inline unsigned int current_alloc_flags(gfp_t gfp_mask, > > > - unsigned int alloc_flags) > > > +static inline unsigned int cma_alloc_flags(gfp_t gfp_mask, > > > + unsigned int alloc_flags) > > > > Do you have any strong reason to rename? Even though the current > > Yes :) > > > implementation only does something for cma I do not think this is all > > that important. The naming nicely fits with current_gfp_context so I > > would stick with it. > > I am renaming because current->flags is removed from this function, > therefore keeping the name > becomes misleading. This function only addresses cma flag check > without looking at the thread local state now. Fair enough. I still dislike cma being called out explicitly because that is slightly misleading as well. gpf_to_alloc_flags would be more explicit I believe. But I do not want to bikeshed this to death.
> Fair enough. I still dislike cma being called out explicitly because > that is slightly misleading as well. gpf_to_alloc_flags would be more > explicit I believe. But I do not want to bikeshed this to death. Sounds good, I renamed it to gpf_to_alloc_flags. Thank you, Pasha
diff --git a/include/linux/mm.h b/include/linux/mm.h index 5299b90a6c40..51b3090dd072 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1109,6 +1109,17 @@ static inline bool is_zone_device_page(const struct page *page) } #endif +static inline bool is_zone_movable_page(const struct page *page) +{ + return page_zonenum(page) == ZONE_MOVABLE; +} + +/* MIGRATE_CMA and ZONE_MOVABLE do not allow pin pages */ +static inline bool is_pinnable_page(struct page *page) +{ + return !is_zone_movable_page(page) && !is_migrate_cma_page(page); +} + #ifdef CONFIG_DEV_PAGEMAP_OPS void free_devmap_managed_page(struct page *page); DECLARE_STATIC_KEY_FALSE(devmap_managed_key); diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h index 5f4dd3274734..a55277b0d475 100644 --- a/include/linux/sched/mm.h +++ b/include/linux/sched/mm.h @@ -150,12 +150,13 @@ static inline bool in_vfork(struct task_struct *tsk) * Applies per-task gfp context to the given allocation flags. * PF_MEMALLOC_NOIO implies GFP_NOIO * PF_MEMALLOC_NOFS implies GFP_NOFS + * PF_MEMALLOC_PIN implies !GFP_MOVABLE */ static inline gfp_t current_gfp_context(gfp_t flags) { unsigned int pflags = READ_ONCE(current->flags); - if (unlikely(pflags & (PF_MEMALLOC_NOIO | PF_MEMALLOC_NOFS))) { + if (unlikely(pflags & (PF_MEMALLOC_NOIO | PF_MEMALLOC_NOFS | PF_MEMALLOC_PIN))) { /* * NOIO implies both NOIO and NOFS and it is a weaker context * so always make sure it makes precedence @@ -164,6 +165,9 @@ static inline gfp_t current_gfp_context(gfp_t flags) flags &= ~(__GFP_IO | __GFP_FS); else if (pflags & PF_MEMALLOC_NOFS) flags &= ~__GFP_FS; + + if (pflags & PF_MEMALLOC_PIN) + flags &= ~__GFP_MOVABLE; } return flags; } diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 012246234eb5..b170ef2e04f5 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1036,7 +1036,7 @@ static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid) bool pin = !!(current->flags & PF_MEMALLOC_PIN); list_for_each_entry(page, &h->hugepage_freelists[nid], lru) { - if (pin && is_migrate_cma_page(page)) + if (pin && !is_pinnable_page(page)) continue; if (PageHWPoison(page)) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index c2dea9ad0e98..4d8e7f801c66 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3802,16 +3802,12 @@ alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask) return alloc_flags; } -static inline unsigned int current_alloc_flags(gfp_t gfp_mask, - unsigned int alloc_flags) +static inline unsigned int cma_alloc_flags(gfp_t gfp_mask, + unsigned int alloc_flags) { #ifdef CONFIG_CMA - unsigned int pflags = current->flags; - - if (!(pflags & PF_MEMALLOC_PIN) && - gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE) + if (gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE) alloc_flags |= ALLOC_CMA; - #endif return alloc_flags; } @@ -4467,7 +4463,7 @@ gfp_to_alloc_flags(gfp_t gfp_mask) } else if (unlikely(rt_task(current)) && !in_interrupt()) alloc_flags |= ALLOC_HARDER; - alloc_flags = current_alloc_flags(gfp_mask, alloc_flags); + alloc_flags = cma_alloc_flags(gfp_mask, alloc_flags); return alloc_flags; } @@ -4769,7 +4765,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, reserve_flags = __gfp_pfmemalloc_flags(gfp_mask); if (reserve_flags) - alloc_flags = current_alloc_flags(gfp_mask, reserve_flags); + alloc_flags = cma_alloc_flags(gfp_mask, reserve_flags); /* * Reset the nodemask and zonelist iterators if memory policies can be @@ -4938,7 +4934,7 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order, if (should_fail_alloc_page(gfp_mask, order)) return false; - *alloc_flags = current_alloc_flags(gfp_mask, *alloc_flags); + *alloc_flags = cma_alloc_flags(gfp_mask, *alloc_flags); /* Dirty zone balancing only done in the fast path */ ac->spread_dirty_pages = (gfp_mask & __GFP_WRITE); @@ -4980,7 +4976,8 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid, * Apply scoped allocation constraints. This is mainly about GFP_NOFS * resp. GFP_NOIO which has to be inherited for all allocation requests * from a particular context which has been marked by - * memalloc_no{fs,io}_{save,restore}. + * memalloc_no{fs,io}_{save,restore}. And PF_MEMALLOC_PIN which ensures + * movable zones are not used during allocation. */ gfp_mask = current_gfp_context(gfp_mask); alloc_mask = gfp_mask;
PF_MEMALLOC_PIN is only honored for CMA pages, extend this flag to work for any allocations from ZONE_MOVABLE by removing __GFP_MOVABLE from gfp_mask when this flag is passed in the current context. Add is_pinnable_page() to return true if page is in a pinnable page. A pinnable page is not in ZONE_MOVABLE and not of MIGRATE_CMA type. Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> --- include/linux/mm.h | 11 +++++++++++ include/linux/sched/mm.h | 6 +++++- mm/hugetlb.c | 2 +- mm/page_alloc.c | 19 ++++++++----------- 4 files changed, 25 insertions(+), 13 deletions(-)