diff options
| author | Alexey Dobriyan <adobriyan@gmail.com> | 2026-04-22 22:17:45 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-05-28 21:24:39 -0700 |
| commit | f7027ed76dfcf4905225272029a83cc74fd1816d (patch) | |
| tree | 5f8952ed70a29b95528e38e8447e27393acd65a8 /fs | |
| parent | 9794de4500e7dc8686f4ae5f2d11d76e43f299c5 (diff) | |
| download | linux-next-history-f7027ed76dfcf4905225272029a83cc74fd1816d.tar.gz | |
proc: rewrite next_tgid()
* deduplicate "iter.tgid += 1" line,
Right now it is done once inside next_tgid() itself and second time
inside "for" loop.
* deduplicate next_tgid() call itself with different loop style:
auto it = make_tgid_iter();
while (next_tgid(&it)) {
...
}
gcc seems to inline it twice:
$ ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux
add/remove: 0/1 grow/shrink: 1/0 up/down: 100/-245 (-145)
Function old new delta
proc_pid_readdir 531 631 +100
next_tgid 245 - -245
* make tgid_iter.pid_ns const
it never changes during readdir anyway
[akpm@linux-foundation.org: remove newline]
Link: https://lore.kernel.org/20260422191745.435556-2-adobriyan@gmail.com
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/proc/base.c | 56 |
1 files changed, 32 insertions, 24 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index f2db455dbbfd2..49344de101582 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -3543,30 +3543,42 @@ out: struct tgid_iter { unsigned int tgid; struct task_struct *task; - struct pid_namespace *pid_ns; + struct pid_namespace *const pid_ns; }; -static struct tgid_iter next_tgid(struct tgid_iter iter) +static struct tgid_iter +make_tgid_iter(unsigned int init_tgid, struct pid_namespace *pid_ns) { - struct pid *pid; + return (struct tgid_iter){ + .tgid = init_tgid - 1, + .pid_ns = pid_ns, + }; +} + +static bool next_tgid(struct tgid_iter *it) +{ + if (it->task) { + put_task_struct(it->task); + it->task = NULL; + } - if (iter.task) - put_task_struct(iter.task); rcu_read_lock(); -retry: - iter.task = NULL; - pid = find_ge_pid(iter.tgid, iter.pid_ns); - if (pid) { - iter.tgid = pid_nr_ns(pid, iter.pid_ns); - iter.task = pid_task(pid, PIDTYPE_TGID); - if (!iter.task) { - iter.tgid += 1; - goto retry; + while (1) { + it->tgid += 1; + const auto pid = find_ge_pid(it->tgid, it->pid_ns); + if (pid) { + it->tgid = pid_nr_ns(pid, it->pid_ns); + it->task = pid_task(pid, PIDTYPE_TGID); + if (it->task) { + get_task_struct(it->task); + rcu_read_unlock(); + return true; + } + } else { + rcu_read_unlock(); + return false; } - get_task_struct(iter.task); } - rcu_read_unlock(); - return iter; } #define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2) @@ -3574,7 +3586,6 @@ retry: /* for the /proc/ directory itself, after non-process stuff has been done */ int proc_pid_readdir(struct file *file, struct dir_context *ctx) { - struct tgid_iter iter; struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb); struct pid_namespace *pid_ns = proc_pid_ns(file_inode(file)->i_sb); loff_t pos = ctx->pos; @@ -3592,12 +3603,9 @@ int proc_pid_readdir(struct file *file, struct dir_context *ctx) return 0; ctx->pos = pos = pos + 1; } - iter.tgid = pos - TGID_OFFSET; - iter.task = NULL; - iter.pid_ns = pid_ns; - for (iter = next_tgid(iter); - iter.task; - iter.tgid += 1, iter = next_tgid(iter)) { + + auto iter = make_tgid_iter(pos - TGID_OFFSET, pid_ns); + while (next_tgid(&iter)) { char name[10 + 1]; unsigned int len; |