From: Roman Gushchin <guro@fb.com>
To: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>, Christoph Lameter <cl@linux.com>,
Andrew Morton <akpm@linux-foundation.org>, <linux-mm@kvack.org>,
<linux-kernel@vger.kernel.org>, Roman Gushchin <guro@fb.com>
Subject: [PATCH v1 2/5] percpu: make pcpu_nr_empty_pop_pages per chunk type
Date: Thu, 1 Apr 2021 14:42:58 -0700 [thread overview]
Message-ID: <20210401214301.1689099-3-guro@fb.com> (raw)
In-Reply-To: <20210401214301.1689099-1-guro@fb.com>
nr_empty_pop_pages is used to guarantee that there are some free
populated pages to satisfy atomic allocations. Accounted and
non-accounted allocations are using separate sets of chunks,
so both need to have a surplus of empty pages.
This commit makes pcpu_nr_empty_pop_pages and the corresponding logic
per chunk type.
Signed-off-by: Roman Gushchin <guro@fb.com>
---
mm/percpu-internal.h | 2 +-
mm/percpu-stats.c | 9 +++++++--
mm/percpu.c | 14 +++++++-------
3 files changed, 15 insertions(+), 10 deletions(-)
diff --git a/mm/percpu-internal.h b/mm/percpu-internal.h
index 18b768ac7dca..095d7eaa0db4 100644
--- a/mm/percpu-internal.h
+++ b/mm/percpu-internal.h
@@ -87,7 +87,7 @@ extern spinlock_t pcpu_lock;
extern struct list_head *pcpu_chunk_lists;
extern int pcpu_nr_slots;
-extern int pcpu_nr_empty_pop_pages;
+extern int pcpu_nr_empty_pop_pages[];
extern struct pcpu_chunk *pcpu_first_chunk;
extern struct pcpu_chunk *pcpu_reserved_chunk;
diff --git a/mm/percpu-stats.c b/mm/percpu-stats.c
index c8400a2adbc2..f6026dbcdf6b 100644
--- a/mm/percpu-stats.c
+++ b/mm/percpu-stats.c
@@ -145,6 +145,7 @@ static int percpu_stats_show(struct seq_file *m, void *v)
int slot, max_nr_alloc;
int *buffer;
enum pcpu_chunk_type type;
+ int nr_empty_pop_pages;
alloc_buffer:
spin_lock_irq(&pcpu_lock);
@@ -165,7 +166,11 @@ static int percpu_stats_show(struct seq_file *m, void *v)
goto alloc_buffer;
}
-#define PL(X) \
+ nr_empty_pop_pages = 0;
+ for (type = 0; type < PCPU_NR_CHUNK_TYPES; type++)
+ nr_empty_pop_pages += pcpu_nr_empty_pop_pages[type];
+
+#define PL(X) \
seq_printf(m, " %-20s: %12lld\n", #X, (long long int)pcpu_stats_ai.X)
seq_printf(m,
@@ -196,7 +201,7 @@ static int percpu_stats_show(struct seq_file *m, void *v)
PU(nr_max_chunks);
PU(min_alloc_size);
PU(max_alloc_size);
- P("empty_pop_pages", pcpu_nr_empty_pop_pages);
+ P("empty_pop_pages", nr_empty_pop_pages);
seq_putc(m, '\n');
#undef PU
diff --git a/mm/percpu.c b/mm/percpu.c
index 5b505a459028..0eeeb4e7a2f9 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -173,10 +173,10 @@ struct list_head *pcpu_chunk_lists __ro_after_init; /* chunk list slots */
static LIST_HEAD(pcpu_map_extend_chunks);
/*
- * The number of empty populated pages, protected by pcpu_lock. The
- * reserved chunk doesn't contribute to the count.
+ * The number of empty populated pages by chunk type, protected by pcpu_lock.
+ * The reserved chunk doesn't contribute to the count.
*/
-int pcpu_nr_empty_pop_pages;
+int pcpu_nr_empty_pop_pages[PCPU_NR_CHUNK_TYPES];
/*
* The number of populated pages in use by the allocator, protected by
@@ -556,7 +556,7 @@ static inline void pcpu_update_empty_pages(struct pcpu_chunk *chunk, int nr)
{
chunk->nr_empty_pop_pages += nr;
if (chunk != pcpu_reserved_chunk)
- pcpu_nr_empty_pop_pages += nr;
+ pcpu_nr_empty_pop_pages[pcpu_chunk_type(chunk)] += nr;
}
/*
@@ -1832,7 +1832,7 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved,
mutex_unlock(&pcpu_alloc_mutex);
}
- if (pcpu_nr_empty_pop_pages < PCPU_EMPTY_POP_PAGES_LOW)
+ if (pcpu_nr_empty_pop_pages[type] < PCPU_EMPTY_POP_PAGES_LOW)
pcpu_schedule_balance_work();
/* clear the areas and return address relative to base address */
@@ -2010,7 +2010,7 @@ static void pcpu_balance_populated(enum pcpu_chunk_type type)
pcpu_atomic_alloc_failed = false;
} else {
nr_to_pop = clamp(PCPU_EMPTY_POP_PAGES_HIGH -
- pcpu_nr_empty_pop_pages,
+ pcpu_nr_empty_pop_pages[type],
0, PCPU_EMPTY_POP_PAGES_HIGH);
}
@@ -2592,7 +2592,7 @@ void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
/* link the first chunk in */
pcpu_first_chunk = chunk;
- pcpu_nr_empty_pop_pages = pcpu_first_chunk->nr_empty_pop_pages;
+ pcpu_nr_empty_pop_pages[PCPU_CHUNK_ROOT] = pcpu_first_chunk->nr_empty_pop_pages;
pcpu_chunk_relocate(pcpu_first_chunk, -1);
/* include all regions of the first chunk */
--
2.30.2
next prev parent reply other threads:[~2021-04-01 21:43 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-01 21:42 [PATCH v1 0/5] percpu: partial chunk depopulation Roman Gushchin
2021-04-01 21:42 ` [PATCH v1 1/5] percpu: split __pcpu_balance_workfn() Roman Gushchin
2021-04-01 21:42 ` Roman Gushchin [this message]
2021-04-01 21:42 ` [PATCH v1 3/5] percpu: generalize pcpu_balance_populated() Roman Gushchin
2021-04-01 21:43 ` [PATCH v1 4/5] percpu: fix a comment about the chunks ordering Roman Gushchin
2021-04-01 21:43 ` [PATCH v1 5/5] percpu: implement partial chunk depopulation Roman Gushchin
2021-04-05 23:02 ` Dennis Zhou
2021-04-07 11:09 ` [PATCH v1 0/5] percpu: " Vlastimil Babka
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=20210401214301.1689099-3-guro@fb.com \
--to=guro@fb.com \
--cc=akpm@linux-foundation.org \
--cc=cl@linux.com \
--cc=dennis@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=tj@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 read-only IMAP folder(s) and NNTP newsgroup(s).