From: Baoquan He <bhe@redhat.com>
To: linux-mm@kvack.org
Cc: akpm@linux-foundation.org, x86@kernel.org,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
rppt@kernel.org
Subject: [PATCH v3 4/6] mm/mm_init.c: remove meaningless calculation of zone->managed_pages in free_area_init_core()
Date: Thu, 28 Mar 2024 17:12:14 +0800 [thread overview]
Message-ID: <ZgU0bsJ2FEjykvju@MiWiFi-R3L-srv> (raw)
In-Reply-To: <20240325145646.1044760-5-bhe@redhat.com>
Currently, in free_area_init_core(), when initialize zone's field, a
rough value is set to zone->managed_pages. That value is calculated by
(zone->present_pages - memmap_pages).
In the meantime, add the value to nr_all_pages and nr_kernel_pages which
represent all free pages of system (only low memory or including HIGHMEM
memory separately). Both of them are gonna be used in
alloc_large_system_hash().
However, the rough calculation and setting of zone->managed_pages is
meaningless because
a) memmap pages are allocated on units of node in sparse_init() or
alloc_node_mem_map(pgdat); The simple (zone->present_pages -
memmap_pages) is too rough to make sense for zone;
b) the set zone->managed_pages will be zeroed out and reset with
acutal value in mem_init() via memblock_free_all(). Before the
resetting, no buddy allocation request is issued.
Here, remove the meaningless and complicated calculation of
(zone->present_pages - memmap_pages), directly set zone->managed_pages
as zone->present_pages for now. It will be adjusted in mem_init().
And also remove the assignment of nr_all_pages and nr_kernel_pages in
free_area_init_core(). Instead, call the newly added calc_nr_kernel_pages()
to count up all free but not reserved memory in memblock and assign to
nr_all_pages and nr_kernel_pages. The counting excludes memmap_pages,
and other kernel used data, which is more accurate than old way and
simpler, and can also cover the ppc required arch_reserved_kernel_pages()
case.
And also clean up the outdated code comment above free_area_init_core().
And free_area_init_core() is easy to understand now, no need to add
words to explain.
Signed-off-by: Baoquan He <bhe@redhat.com>
---
v2->v3:
- Change to initialize zone->managed_pages as zone->present_pages for now
because later page_group_by_mobility_disabled need be set according to
zone->managed_pages. Otherwise it will cause setting
page_group_by_mobility_disabled to 1 always.
mm/mm_init.c | 46 +++++-----------------------------------------
1 file changed, 5 insertions(+), 41 deletions(-)
diff --git a/mm/mm_init.c b/mm/mm_init.c
index c57a7fc97a16..a4b80e8276bb 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -1565,15 +1565,6 @@ void __ref free_area_init_core_hotplug(struct pglist_data *pgdat)
}
#endif
-/*
- * Set up the zone data structures:
- * - mark all pages reserved
- * - mark all memory queues empty
- * - clear the memory bitmaps
- *
- * NOTE: pgdat should get zeroed by caller.
- * NOTE: this function is only called during early init.
- */
static void __init free_area_init_core(struct pglist_data *pgdat)
{
enum zone_type j;
@@ -1584,41 +1575,13 @@ static void __init free_area_init_core(struct pglist_data *pgdat)
for (j = 0; j < MAX_NR_ZONES; j++) {
struct zone *zone = pgdat->node_zones + j;
- unsigned long size, freesize, memmap_pages;
-
- size = zone->spanned_pages;
- freesize = zone->present_pages;
-
- /*
- * Adjust freesize so that it accounts for how much memory
- * is used by this zone for memmap. This affects the watermark
- * and per-cpu initialisations
- */
- memmap_pages = calc_memmap_size(size, freesize);
- if (!is_highmem_idx(j)) {
- if (freesize >= memmap_pages) {
- freesize -= memmap_pages;
- if (memmap_pages)
- pr_debug(" %s zone: %lu pages used for memmap\n",
- zone_names[j], memmap_pages);
- } else
- pr_warn(" %s zone: %lu memmap pages exceeds freesize %lu\n",
- zone_names[j], memmap_pages, freesize);
- }
-
- if (!is_highmem_idx(j))
- nr_kernel_pages += freesize;
- /* Charge for highmem memmap if there are enough kernel pages */
- else if (nr_kernel_pages > memmap_pages * 2)
- nr_kernel_pages -= memmap_pages;
- nr_all_pages += freesize;
+ unsigned long size = zone->spanned_pages;
/*
- * Set an approximate value for lowmem here, it will be adjusted
- * when the bootmem allocator frees pages into the buddy system.
- * And all highmem pages will be managed by the buddy system.
+ * Initialize zone->managed_pages as 0 , it will be reset
+ * when memblock allocator frees pages into buddy system.
*/
- zone_init_internals(zone, j, nid, freesize);
+ zone_init_internals(zone, j, nid, zone->present_pages);
if (!size)
continue;
@@ -1915,6 +1878,7 @@ void __init free_area_init(unsigned long *max_zone_pfn)
check_for_memory(pgdat);
}
+ calc_nr_kernel_pages();
memmap_init();
/* disable hash distribution for systems with a single node */
--
2.41.0
next prev parent reply other threads:[~2024-03-28 9:13 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-25 14:56 [PATCH v2 0/6] mm/mm_init.c: refactor free_area_init_core() Baoquan He
2024-03-25 14:56 ` [PATCH v2 1/6] x86: remove unneeded memblock_find_dma_reserve() Baoquan He
2024-03-26 6:44 ` Mike Rapoport
2024-03-25 14:56 ` [PATCH v2 2/6] mm/mm_init.c: remove the useless dma_reserve Baoquan He
2024-03-26 6:44 ` Mike Rapoport
2024-03-25 14:56 ` [PATCH v2 3/6] mm/mm_init.c: add new function calc_nr_all_pages() Baoquan He
2024-03-26 6:57 ` Mike Rapoport
2024-03-26 13:49 ` Baoquan He
2024-03-27 15:40 ` Mike Rapoport
2024-03-25 14:56 ` [PATCH v2 4/6] mm/mm_init.c: remove meaningless calculation of zone->managed_pages in free_area_init_core() Baoquan He
2024-03-27 15:40 ` Mike Rapoport
2024-03-28 8:32 ` Baoquan He
2024-03-28 9:53 ` Mike Rapoport
2024-03-28 14:46 ` Baoquan He
2024-03-28 9:12 ` Baoquan He [this message]
2024-03-25 14:56 ` [PATCH v2 5/6] mm/mm_init.c: remove unneeded calc_memmap_size() Baoquan He
2024-03-27 16:21 ` Mike Rapoport
2024-03-28 1:24 ` Baoquan He
2024-03-25 14:56 ` [PATCH v2 6/6] mm/mm_init.c: remove arch_reserved_kernel_pages() Baoquan He
2024-03-26 6:57 ` Mike Rapoport
2024-03-27 15:41 ` Mike Rapoport
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ZgU0bsJ2FEjykvju@MiWiFi-R3L-srv \
--to=bhe@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=rppt@kernel.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).