Re: [PATCH v4 10/12] mm/gup: /proc/vmstat: pin_user_pages (FOLL_PIN) reporting
From: John Hubbard <jhubbard@nvidia.com>
Date: 2020-02-05 23:13:36
Also in:
linux-doc, linux-fsdevel, linux-kselftest, linux-rdma, lkml
Subsystem:
memory management, memory management - gup (get user pages), the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
On 2/5/20 1:37 AM, Jan Kara wrote:
...quoted
@@ -104,6 +106,9 @@ static __maybe_unused struct page *try_grab_compound_head(struct page *page, if (hpage_pincount_available(page)) hpage_pincount_add(page, refs); + mod_node_page_state(page_pgdat(page), NR_FOLL_PIN_ACQUIRED, + orig_refs); + return page; }It seems to me you miss mod_node_page_state() in put_compound_head(), don't you?
Yes, that was definitely missing. I've added this for the next version:
diff --git a/mm/gup.c b/mm/gup.c
index 7c543849181b..ae503c51bc7f 100644
--- a/mm/gup.c
+++ b/mm/gup.c@@ -2268,6 +2268,8 @@ static int record_subpages(struct page *page, unsigned long addr, static void put_compound_head(struct page *page, int refs, unsigned int flags) { + int orig_refs = refs; + if (flags & FOLL_PIN) { if (hpage_pincount_available(page)) hpage_pincount_sub(page, refs);
@@ -2283,6 +2285,8 @@ static void put_compound_head(struct page *page, int refs, unsigned int flags) if (refs > 1) page_ref_sub(page, refs - 1); put_page(page); + + mod_node_page_state(page_pgdat(page), NR_FOLL_PIN_RELEASED, orig_refs); } #ifdef CONFIG_ARCH_HAS_HUGEPD
Otherwise I like the new stat names better :). Honza
Glad to hear that! :) thanks, -- John Hubbard NVIDIA