sched/debug: Fix updating of ppos on server write ops

Updating "ppos" on error conditions does not make much sense. The pattern
is to return the error code directly without modifying the position, or
modify the position on success and return the number of bytes written.

Since on success, the return value of apply is 0, there is no point in
modifying ppos either. Fix it by removing all this and just returning
error code or number of bytes written on success.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Acked-by: Tejun Heo <tj@kernel.org>
Tested-by: Christian Loehle <christian.loehle@arm.com>
Link: https://patch.msgid.link/20260126100050.3854740-3-arighi@nvidia.com
master
Joel Fernandes 2026-01-26 10:59:00 +01:00 committed by Peter Zijlstra
parent 3cb3b27693
commit 6080fb2116
1 changed files with 4 additions and 3 deletions

View File

@ -339,8 +339,8 @@ static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubu
long cpu = (long) ((struct seq_file *) filp->private_data)->private;
struct rq *rq = cpu_rq(cpu);
u64 runtime, period;
int retval = 0;
size_t err;
int retval;
u64 value;
err = kstrtoull_from_user(ubuf, cnt, 10, &value);
@ -374,8 +374,6 @@ static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubu
dl_server_stop(&rq->fair_server);
retval = dl_server_apply_params(&rq->fair_server, runtime, period, 0);
if (retval)
cnt = retval;
if (!runtime)
printk_deferred("Fair server disabled in CPU %d, system may crash due to starvation.\n",
@ -383,6 +381,9 @@ static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubu
if (rq->cfs.h_nr_queued)
dl_server_start(&rq->fair_server);
if (retval < 0)
return retval;
}
*ppos += cnt;