search for: adjust_managed_page_count

Enhance adjust_managed_page_count() to adjust totalhigh_pages for highmem pages. And change code which directly adjusts totalram_pages to use adjust_managed_page_count() because it adjusts totalram_pages, totalhigh_pages and zone->managed_pages altogether in a safe way. Remove inc_totalhigh_pages() and dec_totalhigh_pages() fro...

Enhance adjust_managed_page_count() to adjust totalhigh_pages for highmem pages. And change code which directly adjusts totalram_pages to use adjust_managed_page_count() because it adjusts totalram_pages, totalhigh_pages and zone->managed_pages altogether in a safe way. Remove inc_totalhigh_pages() and dec_totalhigh_pages() fro...

Enhance adjust_managed_page_count() to adjust totalhigh_pages for highmem pages. And change code which directly adjusts totalram_pages to use adjust_managed_page_count() because it adjusts totalram_pages, totalhigh_pages and zone->managed_pages altogether in a safe way. Remove inc_totalhigh_pages() and dec_totalhigh_pages() fro...

Enhance adjust_managed_page_count() to adjust totalhigh_pages for highmem pages. And change code which directly adjusts totalram_pages to use adjust_managed_page_count() because it adjusts totalram_pages, totalhigh_pages and zone->managed_pages altogether in a safe way. Remove inc_totalhigh_pages() and dec_totalhigh_pages() fro...

Enhance adjust_managed_page_count() to adjust totalhigh_pages for highmem pages. And change code which directly adjusts totalram_pages to use adjust_managed_page_count() because it adjusts totalram_pages, totalhigh_pages and zone->managed_pages altogether in a safe way. Remove inc_totalhigh_pages() and dec_totalhigh_pages() fro...

Enhance adjust_managed_page_count() to adjust totalhigh_pages for highmem pages. And change code which directly adjusts totalram_pages to use adjust_managed_page_count() because it adjusts totalram_pages, totalhigh_pages and zone->managed_pages altogether in a safe way. Remove inc_totalhigh_pages() and dec_totalhigh_pages() fro...

...really need it (f.e. with OOM in guest and with VIRTIO_BALLOON_F_DEFLATE_ON_OOM configuration flag set). The bad thing is that end-user does not know this. Balloon by default reduce the amount of memory exposed to the end-user each time when the page is stolen from guest or returned back by using adjust_managed_page_count and thus /proc/meminfo shows reduced amount of memory. Fortunately the solution is simple, we should just avoid to call adjust_managed_page_count with VIRTIO_BALLOON_F_DEFLATE_ON_OOM set. Please note that neither VMWare ballon nor HyperV balloon do not care about proper handling of adjust_managed...

...really need it (f.e. with OOM in guest and with VIRTIO_BALLOON_F_DEFLATE_ON_OOM configuration flag set). The bad thing is that end-user does not know this. Balloon by default reduce the amount of memory exposed to the end-user each time when the page is stolen from guest or returned back by using adjust_managed_page_count and thus /proc/meminfo shows reduced amount of memory. Fortunately the solution is simple, we should just avoid to call adjust_managed_page_count with VIRTIO_BALLOON_F_DEFLATE_ON_OOM set. Please note that neither VMWare ballon nor HyperV balloon do not care about proper handling of adjust_managed...

On Wed, Nov 17, 2021 at 07:06:34PM +0900, David Stevens wrote: > From: David Stevens <stevensd at chromium.org> > > Add a module parameters to virtio_balloon to allow specifying whether or > not the driver should call adjust_managed_page_count. If the parameter > is set, it overrides the default behavior inferred from the deflate on > OOM flag. This allows the balloon to operate without changing the amount > of memory visible to userspace via /proc/meminfo or sysinfo, even on a > system that cannot set the default on OOM flag...

...} > > set_page_pfns(vb, vb->pfns + vb->num_pfns, page); > > vb->num_pages += VIRTIO_BALLOON_PAGES_PER_PAGE; > > - if (!virtio_has_feature(vb->vdev, > > + if (virtio_has_feature(vb->vdev, > > VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) > > adjust_managed_page_count(page, -1); > > } > > @@ -184,7 +184,7 @@ static void release_pages_balloon(struct virtio_balloon *vb, > > struct page *page, *next; > > > > list_for_each_entry_safe(page, next, pages, lru) { > > - if (!virtio_has_feature(vb->vdev, > > + if (vir...

...} > > set_page_pfns(vb, vb->pfns + vb->num_pfns, page); > > vb->num_pages += VIRTIO_BALLOON_PAGES_PER_PAGE; > > - if (!virtio_has_feature(vb->vdev, > > + if (virtio_has_feature(vb->vdev, > > VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) > > adjust_managed_page_count(page, -1); > > } > > @@ -184,7 +184,7 @@ static void release_pages_balloon(struct virtio_balloon *vb, > > struct page *page, *next; > > > > list_for_each_entry_safe(page, next, pages, lru) { > > - if (!virtio_has_feature(vb->vdev, > > + if (vir...

...so the memory can get > + * offlined and add the unplugged pages to the managed > + * page counters (so offlining code can correctly subtract > + * them again). > + */ > + pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) + > + sb_id * vm->subblock_size); > + adjust_managed_page_count(pfn_to_page(pfn), nr_pages); > + for (i = 0; i < nr_pages; i++) > + page_ref_dec(pfn_to_page(pfn + i)); Is there ever situation this might be a different than 1->0 transition? -- Michal Hocko SUSE Labs

...so the memory can get > + * offlined and add the unplugged pages to the managed > + * page counters (so offlining code can correctly subtract > + * them again). > + */ > + pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) + > + sb_id * vm->subblock_size); > + adjust_managed_page_count(pfn_to_page(pfn), nr_pages); > + for (i = 0; i < nr_pages; i++) > + page_ref_dec(pfn_to_page(pfn + i)); Is there ever situation this might be a different than 1->0 transition? -- Michal Hocko SUSE Labs

...s/virtio/virtio_balloon.c @@ -742,6 +742,12 @@ static int virtballoon_migratepage(struct balloon_dev_info *vb_dev_info, mutex_unlock(&vb->balloon_lock); + /* fixup the managed page count (esp. of the zone) */ + if (!virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) { + adjust_managed_page_count(page, 1); + adjust_managed_page_count(newpage, -1); + } + put_page(page); /* balloon reference */ return MIGRATEPAGE_SUCCESS; -- 2.21.0

...s/virtio/virtio_balloon.c @@ -742,6 +742,12 @@ static int virtballoon_migratepage(struct balloon_dev_info *vb_dev_info, mutex_unlock(&vb->balloon_lock); + /* fixup the managed page count (esp. of the zone) */ + if (!virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) { + adjust_managed_page_count(page, 1); + adjust_managed_page_count(newpage, -1); + } + put_page(page); /* balloon reference */ return MIGRATEPAGE_SUCCESS; -- 2.21.0

...rying. If that fails go back to a single page. > @@ -206,7 +219,7 @@ static unsigned fill_balloon(struct virtio_balloon *vb, size_t num) > vb->num_pages += VIRTIO_BALLOON_PAGES_PER_PAGE; > if (!virtio_has_feature(vb->vdev, > VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) > - adjust_managed_page_count(page, -1); > + adjust_managed_page_count(page, -(1 << page_order)); > vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE; > } > > @@ -223,13 +236,20 @@ static void release_pages_balloon(struct virtio_balloon *vb, > struct list_head *pages) > { > struct...

...ugzilla.kernel.org/show_bug.cgi?id=53501 Now it has also been expanded to reduce common code used by memory initializion. This is the first part, which applies to v3.9-rc1. It introduces following common helper functions to simplify free_initmem() and free_initrd_mem() on different architectures: adjust_managed_page_count(): will be used to adjust totalram_pages, totalhigh_pages, zone->managed_pages when reserving/unresering a page. __free_reserved_page(): free a reserved page into the buddy system without adjusting page statistics info free_reserved_page(): free a reserved page into the buddy system and adj...

...ugzilla.kernel.org/show_bug.cgi?id=53501 Now it has also been expanded to reduce common code used by memory initializion. This is the first part, which applies to v3.9-rc1. It introduces following common helper functions to simplify free_initmem() and free_initrd_mem() on different architectures: adjust_managed_page_count(): will be used to adjust totalram_pages, totalhigh_pages, zone->managed_pages when reserving/unresering a page. __free_reserved_page(): free a reserved page into the buddy system without adjusting page statistics info free_reserved_page(): free a reserved page into the buddy system and adj...

...retry. */ > msleep(200); > break; > @@ -206,7 +219,7 @@ static unsigned fill_balloon(struct virtio_balloon *vb, size_t num) > vb->num_pages += VIRTIO_BALLOON_PAGES_PER_PAGE; > if (!virtio_has_feature(vb->vdev, > VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) > - adjust_managed_page_count(page, -1); > + adjust_managed_page_count(page, -(1 << page_order)); > vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE; > } > > @@ -223,13 +236,20 @@ static void release_pages_balloon(struct virtio_balloon *vb, > struct list_head *pages) > { > struct...

...retry. */ > msleep(200); > break; > @@ -206,7 +219,7 @@ static unsigned fill_balloon(struct virtio_balloon *vb, size_t num) > vb->num_pages += VIRTIO_BALLOON_PAGES_PER_PAGE; > if (!virtio_has_feature(vb->vdev, > VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) > - adjust_managed_page_count(page, -1); > + adjust_managed_page_count(page, -(1 << page_order)); > vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE; > } > > @@ -223,13 +236,20 @@ static void release_pages_balloon(struct virtio_balloon *vb, > struct list_head *pages) > { > struct...