diff options
| author | Kairui Song <kasong@tencent.com> | 2022-10-24 00:25:33 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-11-08 17:37:22 -0800 |
| commit | ea0ffd0c08d0fef1f6e93eb07badbeeabf6b43d6 (patch) | |
| tree | 7c51a3389015d022f9a2b98a2157e2de31216605 | |
| parent | 5033091de814ab4b5623faed2755f3064e19e2d2 (diff) | |
swap: add a limit for readahead page-cluster value
Currenty there is no upper limit for /proc/sys/vm/page-cluster, and it's a
bit shift value, so it could result in overflow of the 32-bit integer.
Add a reasonable upper limit for it, read-in at most 2**31 pages, which is
a large enough value for readahead.
Link: https://lkml.kernel.org/r/20221023162533.81561-1-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | include/linux/mm.h | 1 | ||||
| -rw-r--r-- | kernel/sysctl.c | 1 | ||||
| -rw-r--r-- | mm/swap.c | 3 |
3 files changed, 4 insertions, 1 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 429ff89bfe06..255931ebf2dc 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -74,6 +74,7 @@ static inline void totalram_pages_add(long count) extern void * high_memory; extern int page_cluster; +extern const int page_cluster_max; #ifdef CONFIG_SYSCTL extern int sysctl_legacy_va_layout; diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 188c305aeb8b..71a4350ac601 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2125,6 +2125,7 @@ static struct ctl_table vm_table[] = { .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = SYSCTL_ZERO, + .extra2 = (void *)&page_cluster_max, }, { .procname = "dirtytime_expire_seconds", diff --git a/mm/swap.c b/mm/swap.c index 2f12a2ee1d3a..b9a6817e07ff 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -43,8 +43,9 @@ #define CREATE_TRACE_POINTS #include <trace/events/pagemap.h> -/* How many pages do we try to swap or page in/out together? */ +/* How many pages do we try to swap or page in/out together? As a power of 2 */ int page_cluster; +const int page_cluster_max = 31; /* Protecting only lru_rotate.fbatch which requires disabling interrupts */ struct lru_rotate { |