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| author | Igor Redko <redkoi@virtuozzo.com> | 2016-03-17 14:19:05 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-23 08:18:35 +0100 |
| commit | 8e03351be73e095f6562ee22629b7b91a3f11453 (patch) | |
| tree | e827ae06bc644f4301ae4b3314da113e18b1afd6 /fs | |
| parent | 03a630fc2e5c7964ffc124dd4f094edb5722af3c (diff) | |
| download | linux-stable-8e03351be73e095f6562ee22629b7b91a3f11453.tar.gz linux-stable-8e03351be73e095f6562ee22629b7b91a3f11453.tar.bz2 linux-stable-8e03351be73e095f6562ee22629b7b91a3f11453.zip | |
mm/page_alloc.c: calculate 'available' memory in a separate function
commit d02bd27bd33dd7e8d22594cd568b81be0cb584cd upstream.
Add a new field, VIRTIO_BALLOON_S_AVAIL, to virtio_balloon memory
statistics protocol, corresponding to 'Available' in /proc/meminfo.
It indicates to the hypervisor how big the balloon can be inflated
without pushing the guest system to swap. This metric would be very
useful in VM orchestration software to improve memory management of
different VMs under overcommit.
This patch (of 2):
Factor out calculation of the available memory counter into a separate
exportable function, in order to be able to use it in other parts of the
kernel.
In particular, it appears a relevant metric to report to the hypervisor
via virtio-balloon statistics interface (in a followup patch).
Signed-off-by: Igor Redko <redkoi@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 4.4 as dependency of commit a1078e821b60
"xen: let alloc_xenballooned_pages() fail if not enough memory free"]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/proc/meminfo.c | 31 |
1 files changed, 1 insertions, 30 deletions
diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c index df4661abadc4..83720460c5bc 100644 --- a/fs/proc/meminfo.c +++ b/fs/proc/meminfo.c @@ -29,10 +29,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v) unsigned long committed; long cached; long available; - unsigned long pagecache; - unsigned long wmark_low = 0; unsigned long pages[NR_LRU_LISTS]; - struct zone *zone; int lru; /* @@ -51,33 +48,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v) for (lru = LRU_BASE; lru < NR_LRU_LISTS; lru++) pages[lru] = global_page_state(NR_LRU_BASE + lru); - for_each_zone(zone) - wmark_low += zone->watermark[WMARK_LOW]; - - /* - * Estimate the amount of memory available for userspace allocations, - * without causing swapping. - */ - available = i.freeram - totalreserve_pages; - - /* - * Not all the page cache can be freed, otherwise the system will - * start swapping. Assume at least half of the page cache, or the - * low watermark worth of cache, needs to stay. - */ - pagecache = pages[LRU_ACTIVE_FILE] + pages[LRU_INACTIVE_FILE]; - pagecache -= min(pagecache / 2, wmark_low); - available += pagecache; - - /* - * Part of the reclaimable slab consists of items that are in use, - * and cannot be freed. Cap this estimate at the low watermark. - */ - available += global_page_state(NR_SLAB_RECLAIMABLE) - - min(global_page_state(NR_SLAB_RECLAIMABLE) / 2, wmark_low); - - if (available < 0) - available = 0; + available = si_mem_available(); /* * Tagged format, for easy grepping and expansion. |