From: Kent Overstreet <kent.overstreet@gmail.com>
This converts memory_stat_format() from seq_buf to printbuf. Printbuf is
simalar to seq_buf except that it heap allocates the string buffer:
here, we were already heap allocating the buffer with kmalloc() so the
conversion is trivial.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
---
mm/memcontrol.c | 54 ++++++++++++++++++++++++-------------------------
1 file changed, 27 insertions(+), 27 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b69979c9ced5..54897e4ac4ef 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -62,7 +62,7 @@
#include <linux/file.h>
#include <linux/resume_user_mode.h>
#include <linux/psi.h>
-#include <linux/seq_buf.h>
+#include <linux/printbuf.h>
#include "internal.h"
#include <net/sock.h>
#include <net/ip.h>
@@ -1490,13 +1490,10 @@ static const unsigned int memcg_vm_event_stat[] = {
#endif
};
-static void memory_stat_format(struct mem_cgroup *memcg, char *buf, int bufsize)
+static void memory_stat_format(struct printbuf *out, struct mem_cgroup *memcg)
{
- struct seq_buf s;
int i;
- seq_buf_init(&s, buf, bufsize);
-
/*
* Provide statistics on the state of the memory subsystem as
* well as cumulative event counters that show past behavior.
@@ -1513,30 +1510,30 @@ static void memory_stat_format(struct mem_cgroup *memcg, char *buf, int bufsize)
u64 size;
size = memcg_page_state_output(memcg, memory_stats[i].idx);
- seq_buf_printf(&s, "%s %llu\n", memory_stats[i].name, size);
+ prt_printf(out, "%s %llu\n", memory_stats[i].name, size);
if (unlikely(memory_stats[i].idx == NR_SLAB_UNRECLAIMABLE_B)) {
size += memcg_page_state_output(memcg,
NR_SLAB_RECLAIMABLE_B);
- seq_buf_printf(&s, "slab %llu\n", size);
+ prt_printf(out, "slab %llu\n", size);
}
}
/* Accumulated memory events */
- seq_buf_printf(&s, "pgscan %lu\n",
- memcg_events(memcg, PGSCAN_KSWAPD) +
- memcg_events(memcg, PGSCAN_DIRECT));
- seq_buf_printf(&s, "pgsteal %lu\n",
- memcg_events(memcg, PGSTEAL_KSWAPD) +
- memcg_events(memcg, PGSTEAL_DIRECT));
+ prt_printf(out, "pgscan %lu\n",
+ memcg_events(memcg, PGSCAN_KSWAPD) +
+ memcg_events(memcg, PGSCAN_DIRECT));
+ prt_printf(out, "pgsteal %lu\n",
+ memcg_events(memcg, PGSTEAL_KSWAPD) +
+ memcg_events(memcg, PGSTEAL_DIRECT));
for (i = 0; i < ARRAY_SIZE(memcg_vm_event_stat); i++)
- seq_buf_printf(&s, "%s %lu\n",
- vm_event_name(memcg_vm_event_stat[i]),
- memcg_events(memcg, memcg_vm_event_stat[i]));
+ prt_printf(out, "%s %lu\n",
+ vm_event_name(memcg_vm_event_stat[i]),
+ memcg_events(memcg, memcg_vm_event_stat[i]));
/* The above should easily fit into one page */
- WARN_ON_ONCE(seq_buf_has_overflowed(&s));
+ WARN_ON_ONCE(!printbuf_remaining(out));
}
#define K(x) ((x) << (PAGE_SHIFT-10))
@@ -1573,7 +1570,8 @@ void mem_cgroup_print_oom_context(struct mem_cgroup *memcg, struct task_struct *
void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg)
{
/* Use static buffer, for the caller is holding oom_lock. */
- static char buf[PAGE_SIZE];
+ static char _buf[PAGE_SIZE];
+ struct printbuf buf = PRINTBUF_EXTERN(_buf, sizeof(_buf));
lockdep_assert_held(&oom_lock);
@@ -1596,8 +1594,8 @@ void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg)
pr_info("Memory cgroup stats for ");
pr_cont_cgroup_path(memcg->css.cgroup);
pr_cont(":");
- memory_stat_format(memcg, buf, sizeof(buf));
- pr_info("%s", buf);
+ memory_stat_format(&buf, memcg);
+ pr_info("%s", buf.buf);
}
/*
@@ -6401,14 +6399,16 @@ static int memory_events_local_show(struct seq_file *m, void *v)
static int memory_stat_show(struct seq_file *m, void *v)
{
struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
- char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ struct printbuf buf = PRINTBUF;
+ int ret;
- if (!buf)
- return -ENOMEM;
- memory_stat_format(memcg, buf, PAGE_SIZE);
- seq_puts(m, buf);
- kfree(buf);
- return 0;
+ memory_stat_format(&buf, memcg);
+ ret = buf.allocation_failure ? -ENOMEM : 0;
+ if (!ret)
+ seq_puts(m, buf.buf);
+
+ printbuf_exit(&buf);
+ return ret;
}
#ifdef CONFIG_NUMA
--
2.35.1