Messages in this thread Patch in this message | | | From | "Matthew Wilcox (Oracle)" <> | Subject | [PATCH v5 22/32] mm/memcontrol.c: Convert to printbuf | Date | Mon, 8 Aug 2022 03:41:18 +0100 |
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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
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