diff options
author | Ingo Molnar <mingo@kernel.org> | 2019-09-16 14:04:28 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2019-09-16 14:05:04 +0200 |
commit | 563c4f85f9f0d63b712081d5b4522152cdcb8b6b (patch) | |
tree | 92351ab2d60d5fd7ce5745d21c9a60ce6d46c5dd /mm | |
parent | 4adcdcea717cb2d8436bef00dd689aa5bc76f11b (diff) | |
parent | 09c7e8b21d67c3c78ab9701dbc0fb1e9f14a0ba5 (diff) |
Merge branch 'sched/rt' into sched/core, to pick up -rt changes
Pick up the first couple of patches working towards PREEMPT_RT.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/balloon_compaction.c | 69 | ||||
-rw-r--r-- | mm/vmalloc.c | 9 |
2 files changed, 50 insertions, 28 deletions
diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c index 83a7b614061f..798275a51887 100644 --- a/mm/balloon_compaction.c +++ b/mm/balloon_compaction.c @@ -21,7 +21,6 @@ static void balloon_page_enqueue_one(struct balloon_dev_info *b_dev_info, * memory corruption is possible and we should stop execution. */ BUG_ON(!trylock_page(page)); - list_del(&page->lru); balloon_page_insert(b_dev_info, page); unlock_page(page); __count_vm_event(BALLOON_INFLATE); @@ -33,8 +32,8 @@ static void balloon_page_enqueue_one(struct balloon_dev_info *b_dev_info, * @b_dev_info: balloon device descriptor where we will insert a new page to * @pages: pages to enqueue - allocated using balloon_page_alloc. * - * Driver must call it to properly enqueue a balloon pages before definitively - * removing it from the guest system. + * Driver must call this function to properly enqueue balloon pages before + * definitively removing them from the guest system. * * Return: number of pages that were enqueued. */ @@ -47,6 +46,7 @@ size_t balloon_page_list_enqueue(struct balloon_dev_info *b_dev_info, spin_lock_irqsave(&b_dev_info->pages_lock, flags); list_for_each_entry_safe(page, tmp, pages, lru) { + list_del(&page->lru); balloon_page_enqueue_one(b_dev_info, page); n_pages++; } @@ -63,12 +63,13 @@ EXPORT_SYMBOL_GPL(balloon_page_list_enqueue); * @n_req_pages: number of requested pages. * * Driver must call this function to properly de-allocate a previous enlisted - * balloon pages before definetively releasing it back to the guest system. + * balloon pages before definitively releasing it back to the guest system. * This function tries to remove @n_req_pages from the ballooned pages and * return them to the caller in the @pages list. * - * Note that this function may fail to dequeue some pages temporarily empty due - * to compaction isolated pages. + * Note that this function may fail to dequeue some pages even if the balloon + * isn't empty - since the page list can be temporarily empty due to compaction + * of isolated pages. * * Return: number of pages that were added to the @pages list. */ @@ -112,12 +113,13 @@ EXPORT_SYMBOL_GPL(balloon_page_list_dequeue); /* * balloon_page_alloc - allocates a new page for insertion into the balloon - * page list. + * page list. + * + * Driver must call this function to properly allocate a new balloon page. + * Driver must call balloon_page_enqueue before definitively removing the page + * from the guest system. * - * Driver must call it to properly allocate a new enlisted balloon page. - * Driver must call balloon_page_enqueue before definitively removing it from - * the guest system. This function returns the page address for the recently - * allocated page or NULL in the case we fail to allocate a new page this turn. + * Return: struct page for the allocated page or NULL on allocation failure. */ struct page *balloon_page_alloc(void) { @@ -128,15 +130,17 @@ struct page *balloon_page_alloc(void) EXPORT_SYMBOL_GPL(balloon_page_alloc); /* - * balloon_page_enqueue - allocates a new page and inserts it into the balloon - * page list. - * @b_dev_info: balloon device descriptor where we will insert a new page to + * balloon_page_enqueue - inserts a new page into the balloon page list. + * + * @b_dev_info: balloon device descriptor where we will insert a new page * @page: new page to enqueue - allocated using balloon_page_alloc. * - * Driver must call it to properly enqueue a new allocated balloon page - * before definitively removing it from the guest system. - * This function returns the page address for the recently enqueued page or - * NULL in the case we fail to allocate a new page this turn. + * Drivers must call this function to properly enqueue a new allocated balloon + * page before definitively removing the page from the guest system. + * + * Drivers must not call balloon_page_enqueue on pages that have been pushed to + * a list with balloon_page_push before removing them with balloon_page_pop. To + * enqueue a list of pages, use balloon_page_list_enqueue instead. */ void balloon_page_enqueue(struct balloon_dev_info *b_dev_info, struct page *page) @@ -151,14 +155,23 @@ EXPORT_SYMBOL_GPL(balloon_page_enqueue); /* * balloon_page_dequeue - removes a page from balloon's page list and returns - * the its address to allow the driver release the page. + * its address to allow the driver to release the page. * @b_dev_info: balloon device decriptor where we will grab a page from. * - * Driver must call it to properly de-allocate a previous enlisted balloon page - * before definetively releasing it back to the guest system. - * This function returns the page address for the recently dequeued page or - * NULL in the case we find balloon's page list temporarily empty due to - * compaction isolated pages. + * Driver must call this function to properly dequeue a previously enqueued page + * before definitively releasing it back to the guest system. + * + * Caller must perform its own accounting to ensure that this + * function is called only if some pages are actually enqueued. + * + * Note that this function may fail to dequeue some pages even if there are + * some enqueued pages - since the page list can be temporarily empty due to + * the compaction of isolated pages. + * + * TODO: remove the caller accounting requirements, and allow caller to wait + * until all pages can be dequeued. + * + * Return: struct page for the dequeued page, or NULL if no page was dequeued. */ struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info) { @@ -171,9 +184,9 @@ struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info) if (n_pages != 1) { /* * If we are unable to dequeue a balloon page because the page - * list is empty and there is no isolated pages, then something + * list is empty and there are no isolated pages, then something * went out of track and some balloon pages are lost. - * BUG() here, otherwise the balloon driver may get stuck into + * BUG() here, otherwise the balloon driver may get stuck in * an infinite loop while attempting to release all its pages. */ spin_lock_irqsave(&b_dev_info->pages_lock, flags); @@ -224,8 +237,8 @@ int balloon_page_migrate(struct address_space *mapping, /* * We can not easily support the no copy case here so ignore it as it - * is unlikely to be use with ballon pages. See include/linux/hmm.h for - * user of the MIGRATE_SYNC_NO_COPY mode. + * is unlikely to be used with balloon pages. See include/linux/hmm.h + * for a user of the MIGRATE_SYNC_NO_COPY mode. */ if (mode == MIGRATE_SYNC_NO_COPY) return -EINVAL; diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 4fa8d84599b0..e0fc963acc41 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1259,6 +1259,12 @@ static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end) return false; /* + * First make sure the mappings are removed from all page-tables + * before they are freed. + */ + vmalloc_sync_all(); + + /* * TODO: to calculate a flush range without looping. * The list can be up to lazy_max_pages() elements. */ @@ -3038,6 +3044,9 @@ EXPORT_SYMBOL(remap_vmalloc_range); /* * Implement a stub for vmalloc_sync_all() if the architecture chose not to * have one. + * + * The purpose of this function is to make sure the vmalloc area + * mappings are identical in all page-tables in the system. */ void __weak vmalloc_sync_all(void) { |