From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, bigeasy@linutronix.de,
linux-mm@kvack.org, minchan@kernel.org,
mm-commits@vger.kernel.org, peterz@infradead.org,
tglx@linutronix.de, torvalds@linux-foundation.org,
umgwanakikbuti@gmail.com
Subject: [patch 44/69] zsmalloc: introduce some helper functions
Date: Fri, 21 Jan 2022 22:13:51 -0800 [thread overview]
Message-ID: <20220122061351.w-NKvbX3q%akpm@linux-foundation.org> (raw)
In-Reply-To: <20220121221021.60533b009c357d660791476e@linux-foundation.org>
From: Minchan Kim <minchan@kernel.org>
Subject: zsmalloc: introduce some helper functions
Patch series "zsmalloc: remove bit_spin_lock", v2.
zsmalloc uses bit_spin_lock to minimize space overhead since it's zpage
granularity lock. However, it causes zsmalloc non-working under
PREEMPT_RT as well as adding too much complication.
This patchset tries to replace the bit_spin_lock with per-pool rwlock. It
also removes unnecessary zspage isolation logic from class, which was the
other part too much complication added into zsmalloc.
Last patch changes the get_cpu_var to local_lock to make it work in
PREEMPT_RT.
This patch (of 9):
get_zspage_mapping returns fullness as well as class_idx. However, the
fullness is usually not used since it could be stale in some contexts. It
causes misleading as well as unnecessary instructions so this patch
introduces zspage_class.
obj_to_location also produces page and index but we don't need always the
index, either so this patch introduces obj_to_page.
Link: https://lkml.kernel.org/r/20211115185909.3949505-1-minchan@kernel.org
Link: https://lkml.kernel.org/r/20211115185909.3949505-2-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/zsmalloc.c | 54 ++++++++++++++++++++----------------------------
1 file changed, 23 insertions(+), 31 deletions(-)
--- a/mm/zsmalloc.c~zsmalloc-introduce-some-helper-functions
+++ a/mm/zsmalloc.c
@@ -517,6 +517,12 @@ static void get_zspage_mapping(struct zs
*class_idx = zspage->class;
}
+static struct size_class *zspage_class(struct zs_pool *pool,
+ struct zspage *zspage)
+{
+ return pool->size_class[zspage->class];
+}
+
static void set_zspage_mapping(struct zspage *zspage,
unsigned int class_idx,
enum fullness_group fullness)
@@ -844,6 +850,12 @@ static void obj_to_location(unsigned lon
*obj_idx = (obj & OBJ_INDEX_MASK);
}
+static void obj_to_page(unsigned long obj, struct page **page)
+{
+ obj >>= OBJ_TAG_BITS;
+ *page = pfn_to_page(obj >> OBJ_INDEX_BITS);
+}
+
/**
* location_to_obj - get obj value encoded from (<page>, <obj_idx>)
* @page: page object resides in zspage
@@ -1246,8 +1258,6 @@ void *zs_map_object(struct zs_pool *pool
unsigned long obj, off;
unsigned int obj_idx;
- unsigned int class_idx;
- enum fullness_group fg;
struct size_class *class;
struct mapping_area *area;
struct page *pages[2];
@@ -1270,8 +1280,7 @@ void *zs_map_object(struct zs_pool *pool
/* migration cannot move any subpage in this zspage */
migrate_read_lock(zspage);
- get_zspage_mapping(zspage, &class_idx, &fg);
- class = pool->size_class[class_idx];
+ class = zspage_class(pool, zspage);
off = (class->size * obj_idx) & ~PAGE_MASK;
area = &get_cpu_var(zs_map_area);
@@ -1304,16 +1313,13 @@ void zs_unmap_object(struct zs_pool *poo
unsigned long obj, off;
unsigned int obj_idx;
- unsigned int class_idx;
- enum fullness_group fg;
struct size_class *class;
struct mapping_area *area;
obj = handle_to_obj(handle);
obj_to_location(obj, &page, &obj_idx);
zspage = get_zspage(page);
- get_zspage_mapping(zspage, &class_idx, &fg);
- class = pool->size_class[class_idx];
+ class = zspage_class(pool, zspage);
off = (class->size * obj_idx) & ~PAGE_MASK;
area = this_cpu_ptr(&zs_map_area);
@@ -1491,8 +1497,6 @@ void zs_free(struct zs_pool *pool, unsig
struct zspage *zspage;
struct page *f_page;
unsigned long obj;
- unsigned int f_objidx;
- int class_idx;
struct size_class *class;
enum fullness_group fullness;
bool isolated;
@@ -1502,13 +1506,11 @@ void zs_free(struct zs_pool *pool, unsig
pin_tag(handle);
obj = handle_to_obj(handle);
- obj_to_location(obj, &f_page, &f_objidx);
+ obj_to_page(obj, &f_page);
zspage = get_zspage(f_page);
migrate_read_lock(zspage);
-
- get_zspage_mapping(zspage, &class_idx, &fullness);
- class = pool->size_class[class_idx];
+ class = zspage_class(pool, zspage);
spin_lock(&class->lock);
obj_free(class, obj);
@@ -1866,8 +1868,6 @@ static bool zs_page_isolate(struct page
{
struct zs_pool *pool;
struct size_class *class;
- int class_idx;
- enum fullness_group fullness;
struct zspage *zspage;
struct address_space *mapping;
@@ -1880,15 +1880,10 @@ static bool zs_page_isolate(struct page
zspage = get_zspage(page);
- /*
- * Without class lock, fullness could be stale while class_idx is okay
- * because class_idx is constant unless page is freed so we should get
- * fullness again under class lock.
- */
- get_zspage_mapping(zspage, &class_idx, &fullness);
mapping = page_mapping(page);
pool = mapping->private_data;
- class = pool->size_class[class_idx];
+
+ class = zspage_class(pool, zspage);
spin_lock(&class->lock);
if (get_zspage_inuse(zspage) == 0) {
@@ -1907,6 +1902,9 @@ static bool zs_page_isolate(struct page
* size_class to prevent further object allocation from the zspage.
*/
if (!list_empty(&zspage->list) && !is_zspage_isolated(zspage)) {
+ enum fullness_group fullness;
+ unsigned int class_idx;
+
get_zspage_mapping(zspage, &class_idx, &fullness);
atomic_long_inc(&pool->isolated_pages);
remove_zspage(class, zspage, fullness);
@@ -1923,8 +1921,6 @@ static int zs_page_migrate(struct addres
{
struct zs_pool *pool;
struct size_class *class;
- int class_idx;
- enum fullness_group fullness;
struct zspage *zspage;
struct page *dummy;
void *s_addr, *d_addr, *addr;
@@ -1949,9 +1945,8 @@ static int zs_page_migrate(struct addres
/* Concurrent compactor cannot migrate any subpage in zspage */
migrate_write_lock(zspage);
- get_zspage_mapping(zspage, &class_idx, &fullness);
pool = mapping->private_data;
- class = pool->size_class[class_idx];
+ class = zspage_class(pool, zspage);
offset = get_first_obj_offset(page);
spin_lock(&class->lock);
@@ -2049,8 +2044,6 @@ static void zs_page_putback(struct page
{
struct zs_pool *pool;
struct size_class *class;
- int class_idx;
- enum fullness_group fg;
struct address_space *mapping;
struct zspage *zspage;
@@ -2058,10 +2051,9 @@ static void zs_page_putback(struct page
VM_BUG_ON_PAGE(!PageIsolated(page), page);
zspage = get_zspage(page);
- get_zspage_mapping(zspage, &class_idx, &fg);
mapping = page_mapping(page);
pool = mapping->private_data;
- class = pool->size_class[class_idx];
+ class = zspage_class(pool, zspage);
spin_lock(&class->lock);
dec_zspage_isolation(zspage);
_
next prev parent reply other threads:[~2022-01-22 6:13 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-22 6:10 incoming Andrew Morton
2022-01-22 6:10 ` [patch 01/69] mm/migrate.c: rework migration_entry_wait() to not take a pageref Andrew Morton
2022-01-22 6:10 ` [patch 02/69] sysctl: add a new register_sysctl_init() interface Andrew Morton
2022-01-22 6:10 ` [patch 03/69] sysctl: move some boundary constants from sysctl.c to sysctl_vals Andrew Morton
2022-01-22 6:11 ` [patch 04/69] hung_task: move hung_task sysctl interface to hung_task.c Andrew Morton
2022-01-22 6:11 ` [patch 05/69] watchdog: move watchdog sysctl interface to watchdog.c Andrew Morton
2022-01-22 6:11 ` [patch 06/69] sysctl: make ngroups_max const Andrew Morton
2022-01-22 6:11 ` [patch 07/69] sysctl: use const for typically used max/min proc sysctls Andrew Morton
2022-01-22 6:11 ` [patch 08/69] sysctl: use SYSCTL_ZERO to replace some static int zero uses Andrew Morton
2022-01-22 6:11 ` [patch 09/69] aio: move aio sysctl to aio.c Andrew Morton
2022-01-22 6:11 ` [patch 10/69] dnotify: move dnotify sysctl to dnotify.c Andrew Morton
2022-01-22 6:11 ` [patch 11/69] hpet: simplify subdirectory registration with register_sysctl() Andrew Morton
2022-01-22 6:11 ` [patch 12/69] i915: " Andrew Morton
2022-01-22 6:11 ` [patch 13/69] macintosh/mac_hid.c: " Andrew Morton
2022-01-22 6:11 ` [patch 14/69] ocfs2: " Andrew Morton
2022-01-22 6:11 ` [patch 15/69] test_sysctl: " Andrew Morton
2022-01-22 6:11 ` [patch 16/69] inotify: " Andrew Morton
2022-01-22 6:12 ` [patch 17/69] cdrom: " Andrew Morton
2022-01-22 6:12 ` [patch 18/69] eventpoll: simplify sysctl declaration " Andrew Morton
2022-01-22 6:12 ` [patch 19/69] firmware_loader: move firmware sysctl to its own files Andrew Morton
2022-01-22 6:12 ` [patch 20/69] random: move the random sysctl declarations to its own file Andrew Morton
2022-01-22 6:12 ` [patch 21/69] sysctl: add helper to register a sysctl mount point Andrew Morton
2022-01-22 6:12 ` [patch 22/69] fs: move binfmt_misc sysctl to its own file Andrew Morton
2022-02-07 13:27 ` [PATCH] Fix regression due to "fs: move binfmt_misc sysctl to its own file" Domenico Andreoli
2022-02-07 21:46 ` Luis Chamberlain
2022-02-07 22:53 ` Tong Zhang
2022-02-08 17:20 ` Luis Chamberlain
2022-02-09 7:31 ` Domenico Andreoli
2022-02-09 7:49 ` [PATCH v2] " Domenico Andreoli
2022-02-09 7:55 ` Tong Zhang
2022-02-13 15:34 ` Ido Schimmel
2022-02-13 21:10 ` Tong Zhang
2022-02-14 7:47 ` Ido Schimmel
2022-02-08 6:46 ` [PATCH] " Thorsten Leemhuis
2022-01-22 6:12 ` [patch 23/69] printk: move printk sysctl to printk/sysctl.c Andrew Morton
2022-01-22 6:12 ` [patch 24/69] scsi/sg: move sg-big-buff sysctl to scsi/sg.c Andrew Morton
2022-01-22 6:12 ` [patch 25/69] stackleak: move stack_erasing sysctl to stackleak.c Andrew Morton
2022-01-22 6:12 ` [patch 26/69] sysctl: share unsigned long const values Andrew Morton
2022-01-22 6:12 ` [patch 27/69] fs: move inode sysctls to its own file Andrew Morton
2022-01-22 6:12 ` [patch 28/69] fs: move fs stat sysctls to file_table.c Andrew Morton
2022-01-22 6:12 ` [patch 29/69] fs: move dcache sysctls to its own file Andrew Morton
2022-01-22 6:13 ` [patch 30/69] sysctl: move maxolduid as a sysctl specific const Andrew Morton
2022-01-22 6:13 ` [patch 31/69] fs: move shared sysctls to fs/sysctls.c Andrew Morton
2022-01-22 6:13 ` [patch 32/69] fs: move locking sysctls where they are used Andrew Morton
2022-01-22 6:13 ` [patch 33/69] fs: move namei sysctls to its own file Andrew Morton
2022-01-22 6:13 ` [patch 34/69] fs: move fs/exec.c sysctls into " Andrew Morton
2022-01-22 6:13 ` [patch 35/69] fs: move pipe sysctls to is " Andrew Morton
2022-01-22 6:13 ` [patch 36/69] sysctl: add and use base directory declarer and registration helper Andrew Morton
2022-01-22 6:13 ` [patch 37/69] fs: move namespace sysctls and declare fs base directory Andrew Morton
2022-01-22 6:13 ` [patch 38/69] kernel/sysctl.c: rename sysctl_init() to sysctl_init_bases() Andrew Morton
2022-01-22 6:13 ` [patch 39/69] printk: fix build warning when CONFIG_PRINTK=n Andrew Morton
2022-01-22 6:13 ` [patch 40/69] fs/coredump: move coredump sysctls into its own file Andrew Morton
2022-01-22 6:13 ` [patch 41/69] kprobe: move sysctl_kprobes_optimization to kprobes.c Andrew Morton
2022-01-22 6:13 ` [patch 42/69] kernel/sysctl.c: remove unused variable ten_thousand Andrew Morton
2022-01-22 6:13 ` [patch 43/69] sysctl: returns -EINVAL when a negative value is passed to proc_doulongvec_minmax Andrew Morton
2022-01-22 6:13 ` Andrew Morton [this message]
2022-01-22 6:13 ` [patch 45/69] zsmalloc: rename zs_stat_type to class_stat_type Andrew Morton
2022-01-22 6:13 ` [patch 46/69] zsmalloc: decouple class actions from zspage works Andrew Morton
2022-01-22 6:14 ` [patch 47/69] zsmalloc: introduce obj_allocated Andrew Morton
2022-01-22 6:14 ` [patch 48/69] zsmalloc: move huge compressed obj from page to zspage Andrew Morton
2022-01-22 6:14 ` [patch 49/69] zsmalloc: remove zspage isolation for migration Andrew Morton
2022-01-22 6:14 ` [patch 50/69] locking/rwlocks: introduce write_lock_nested Andrew Morton
2022-01-22 6:14 ` [patch 51/69] zsmalloc: replace per zpage lock with pool->migrate_lock Andrew Morton
2022-01-22 6:14 ` [patch 52/69] zsmalloc: replace get_cpu_var with local_lock Andrew Morton
2022-01-22 6:14 ` [patch 53/69] fs: proc: store PDE()->data into inode->i_private Andrew Morton
2022-01-22 6:14 ` [patch 54/69] proc: remove PDE_DATA() completely Andrew Morton
2022-01-22 6:14 ` [patch 55/69] lib/stackdepot: allow optional init and stack_table allocation by kvmalloc() Andrew Morton
2022-01-22 6:14 ` [patch 56/69] lib/stackdepot: always do filter_irq_stacks() in stack_depot_save() Andrew Morton
2022-01-22 6:14 ` [patch 57/69] mm: remove cleancache Andrew Morton
2022-01-22 6:14 ` [patch 58/69] frontswap: remove frontswap_writethrough Andrew Morton
2022-01-22 6:14 ` [patch 59/69] frontswap: remove frontswap_tmem_exclusive_gets Andrew Morton
2022-01-22 6:14 ` [patch 60/69] frontswap: remove frontswap_shrink Andrew Morton
2022-01-22 6:14 ` [patch 61/69] frontswap: remove frontswap_curr_pages Andrew Morton
2022-01-22 6:14 ` [patch 62/69] frontswap: simplify frontswap_init Andrew Morton
2022-01-22 6:14 ` [patch 63/69] frontswap: remove the frontswap exports Andrew Morton
2022-01-22 6:14 ` [patch 64/69] mm: simplify try_to_unuse Andrew Morton
2022-01-22 6:15 ` [patch 65/69] frontswap: remove frontswap_test Andrew Morton
2022-01-22 6:15 ` [patch 66/69] frontswap: simplify frontswap_register_ops Andrew Morton
2022-01-22 6:15 ` [patch 67/69] mm: mark swap_lock and swap_active_head static Andrew Morton
2022-01-22 6:15 ` [patch 68/69] frontswap: remove support for multiple ops Andrew Morton
2022-01-22 6:15 ` [patch 69/69] mm: hide the FRONTSWAP Kconfig symbol Andrew Morton
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