From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Rokudo Yan <wu-yan@tcl.com>,
Minchan Kim <minchan@kernel.org>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: [PATCH 4.19 48/52] zsmalloc: account the number of compacted pages correctly
Date: Fri, 5 Mar 2021 13:22:19 +0100 [thread overview]
Message-ID: <20210305120856.014050999@linuxfoundation.org> (raw)
In-Reply-To: <20210305120853.659441428@linuxfoundation.org>
From: Rokudo Yan <wu-yan@tcl.com>
commit 2395928158059b8f9858365fce7713ce7fef62e4 upstream.
There exists multiple path may do zram compaction concurrently.
1. auto-compaction triggered during memory reclaim
2. userspace utils write zram<id>/compaction node
So, multiple threads may call zs_shrinker_scan/zs_compact concurrently.
But pages_compacted is a per zsmalloc pool variable and modification
of the variable is not serialized(through under class->lock).
There are two issues here:
1. the pages_compacted may not equal to total number of pages
freed(due to concurrently add).
2. zs_shrinker_scan may not return the correct number of pages
freed(issued by current shrinker).
The fix is simple:
1. account the number of pages freed in zs_compact locally.
2. use actomic variable pages_compacted to accumulate total number.
Link: https://lkml.kernel.org/r/20210202122235.26885-1-wu-yan@tcl.com
Fixes: 860c707dca155a56 ("zsmalloc: account the number of compacted pages")
Signed-off-by: Rokudo Yan <wu-yan@tcl.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/block/zram/zram_drv.c | 2 +-
include/linux/zsmalloc.h | 2 +-
mm/zsmalloc.c | 17 +++++++++++------
3 files changed, 13 insertions(+), 8 deletions(-)
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -873,7 +873,7 @@ static ssize_t mm_stat_show(struct devic
zram->limit_pages << PAGE_SHIFT,
max_used << PAGE_SHIFT,
(u64)atomic64_read(&zram->stats.same_pages),
- pool_stats.pages_compacted,
+ atomic_long_read(&pool_stats.pages_compacted),
(u64)atomic64_read(&zram->stats.huge_pages));
up_read(&zram->init_lock);
--- a/include/linux/zsmalloc.h
+++ b/include/linux/zsmalloc.h
@@ -36,7 +36,7 @@ enum zs_mapmode {
struct zs_pool_stats {
/* How many pages were migrated (freed) */
- unsigned long pages_compacted;
+ atomic_long_t pages_compacted;
};
struct zs_pool;
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -2285,11 +2285,13 @@ static unsigned long zs_can_compact(stru
return obj_wasted * class->pages_per_zspage;
}
-static void __zs_compact(struct zs_pool *pool, struct size_class *class)
+static unsigned long __zs_compact(struct zs_pool *pool,
+ struct size_class *class)
{
struct zs_compact_control cc;
struct zspage *src_zspage;
struct zspage *dst_zspage = NULL;
+ unsigned long pages_freed = 0;
spin_lock(&class->lock);
while ((src_zspage = isolate_zspage(class, true))) {
@@ -2319,7 +2321,7 @@ static void __zs_compact(struct zs_pool
putback_zspage(class, dst_zspage);
if (putback_zspage(class, src_zspage) == ZS_EMPTY) {
free_zspage(pool, class, src_zspage);
- pool->stats.pages_compacted += class->pages_per_zspage;
+ pages_freed += class->pages_per_zspage;
}
spin_unlock(&class->lock);
cond_resched();
@@ -2330,12 +2332,15 @@ static void __zs_compact(struct zs_pool
putback_zspage(class, src_zspage);
spin_unlock(&class->lock);
+
+ return pages_freed;
}
unsigned long zs_compact(struct zs_pool *pool)
{
int i;
struct size_class *class;
+ unsigned long pages_freed = 0;
for (i = ZS_SIZE_CLASSES - 1; i >= 0; i--) {
class = pool->size_class[i];
@@ -2343,10 +2348,11 @@ unsigned long zs_compact(struct zs_pool
continue;
if (class->index != i)
continue;
- __zs_compact(pool, class);
+ pages_freed += __zs_compact(pool, class);
}
+ atomic_long_add(pages_freed, &pool->stats.pages_compacted);
- return pool->stats.pages_compacted;
+ return pages_freed;
}
EXPORT_SYMBOL_GPL(zs_compact);
@@ -2363,13 +2369,12 @@ static unsigned long zs_shrinker_scan(st
struct zs_pool *pool = container_of(shrinker, struct zs_pool,
shrinker);
- pages_freed = pool->stats.pages_compacted;
/*
* Compact classes and calculate compaction delta.
* Can run concurrently with a manually triggered
* (by user) compaction.
*/
- pages_freed = zs_compact(pool) - pages_freed;
+ pages_freed = zs_compact(pool);
return pages_freed ? pages_freed : SHRINK_STOP;
}
next prev parent reply other threads:[~2021-03-05 12:39 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-05 12:21 [PATCH 4.19 00/52] 4.19.179-rc1 review Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 01/52] net: usb: qmi_wwan: support ZTE P685M modem Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 02/52] hugetlb: fix update_and_free_page contig page struct assumption Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 03/52] drm/virtio: use kvmalloc for large allocations Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 04/52] virtio/s390: implement virtio-ccw revision 2 correctly Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 05/52] arm64 module: set plt* section addresses to 0x0 Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 06/52] arm64: Avoid redundant type conversions in xchg() and cmpxchg() Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 07/52] arm64: cmpxchg: Use "K" instead of "L" for ll/sc immediate constraint Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 08/52] arm64: Use correct ll/sc atomic constraints Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 09/52] MIPS: VDSO: Use CLANG_FLAGS instead of filtering out --target= Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 10/52] JFS: more checks for invalid superblock Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 11/52] udlfb: Fix memory leak in dlfb_usb_probe Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 12/52] media: mceusb: sanity check for prescaler value Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 13/52] xfs: Fix assert failure in xfs_setattr_size() Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 14/52] smackfs: restrict bytes count in smackfs write functions Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 15/52] net: fix up truesize of cloned skb in skb_prepare_for_shift() Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 16/52] mm/hugetlb.c: fix unnecessary address expansion of pmd sharing Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 17/52] net: bridge: use switchdev for port flags set through sysfs too Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 18/52] dt-bindings: net: btusb: DT fix s/interrupt-name/interrupt-names/ Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 19/52] rsi: Fix TX EAPOL packet handling against iwlwifi AP Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 20/52] rsi: Move card interrupt handling to RX thread Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 21/52] staging: fwserial: Fix error handling in fwserial_create Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 22/52] x86/reboot: Add Zotac ZBOX CI327 nano PCI reboot quirk Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 23/52] vt/consolemap: do font sum unsigned Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 24/52] wlcore: Fix command execute failure 19 for wl12xx Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 25/52] Bluetooth: hci_h5: Set HCI_QUIRK_SIMULTANEOUS_DISCOVERY for btrtl Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 26/52] pktgen: fix misuse of BUG_ON() in pktgen_thread_worker() Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 27/52] ath10k: fix wmi mgmt tx queue full due to race condition Greg Kroah-Hartman
2021-03-05 12:21 ` [PATCH 4.19 28/52] x86/build: Treat R_386_PLT32 relocation as R_386_PC32 Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 29/52] Bluetooth: Fix null pointer dereference in amp_read_loc_assoc_final_data Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 30/52] staging: most: sound: add sanity check for function argument Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 31/52] crypto: tcrypt - avoid signed overflow in byte count Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 32/52] PCI: Add a REBAR size quirk for Sapphire RX 5600 XT Pulse Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 33/52] drm/amd/display: Guard against NULL pointer deref when get_i2c_info fails Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 34/52] media: uvcvideo: Allow entities with no pads Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 35/52] f2fs: handle unallocated section and zone on pinned/atgc Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 36/52] f2fs: fix to set/clear I_LINKABLE under i_lock Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 37/52] btrfs: fix error handling in commit_fs_roots Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 38/52] parisc: Bump 64-bit IRQ stack size to 64 KB Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 39/52] ASoC: Intel: bytcr_rt5640: Add quirk for the Estar Beauty HD MID 7316R tablet Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 40/52] ASoC: Intel: bytcr_rt5640: Add quirk for the Voyo Winpad A15 tablet Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 41/52] ASoC: Intel: bytcr_rt5640: Add quirk for the Acer One S1002 tablet Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 42/52] scsi: iscsi: Restrict sessions and handles to admin capabilities Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 43/52] sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 44/52] scsi: iscsi: Ensure sysfs attributes are limited to PAGE_SIZE Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 45/52] scsi: iscsi: Verify lengths on passthrough PDUs Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 46/52] Xen/gnttab: handle p2m update errors on a per-slot basis Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 47/52] xen-netback: respect gnttab_map_refs()s return value Greg Kroah-Hartman
2021-03-05 12:22 ` Greg Kroah-Hartman [this message]
2021-03-05 12:22 ` [PATCH 4.19 49/52] swap: fix swapfile read/write offset Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 50/52] media: v4l: ioctl: Fix memory leak in video_usercopy Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 51/52] ALSA: hda/realtek: Add quirk for Clevo NH55RZQ Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.19 52/52] ALSA: hda/realtek: Apply dual codec quirks for MSI Godlike X570 board Greg Kroah-Hartman
2021-03-06 1:00 ` [PATCH 4.19 00/52] 4.19.179-rc1 review Samuel Zou
2021-03-06 10:10 ` Naresh Kamboju
2021-03-06 16:31 ` Guenter Roeck
2021-03-07 22:57 ` Pavel Machek
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