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net: split off __napi_busy_poll from napi_busy_poll

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This splits off the key part of the napi_busy_poll function into its own
function, __napi_busy_poll, and changes the prefer_busy_poll bool to be
flag based to allow passing in more flags in the future.

This is done in preparation for an additional napi_busy_poll() function,
that doesn't take the rcu_read_lock(). The new function is introduced
in the next patch.

Signed-off-by: Stefan Roesch <shr@devkernel.io>
Link: https://lore.kernel.org/r/20230608163839.2891748-2-shr@devkernel.io
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Stefan Roesch
2024-02-06 09:30:03 -07:00
committed by Jakub Kicinski
parent 54be6c6c5a
commit 13d381b440
1 changed files with 28 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files
net/core/dev.c
+28 -14
View File
@@ -6177,8 +6177,12 @@ static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
clear_bit(NAPI_STATE_SCHED, &napi->state);
}
static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll,
u16 budget)
enum {
NAPI_F_PREFER_BUSY_POLL = 1,
};
static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock,
unsigned flags, u16 budget)
{
bool skip_schedule = false;
unsigned long timeout;
@@ -6198,7 +6202,7 @@ static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool
local_bh_disable();
if (prefer_busy_poll) {
if (flags & NAPI_F_PREFER_BUSY_POLL) {
napi->defer_hard_irqs_count = READ_ONCE(napi->dev->napi_defer_hard_irqs);
timeout = READ_ONCE(napi->dev->gro_flush_timeout);
if (napi->defer_hard_irqs_count && timeout) {
@@ -6222,23 +6226,23 @@ static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool
local_bh_enable();
}
void napi_busy_loop(unsigned int napi_id,
bool (*loop_end)(void *, unsigned long),
void *loop_end_arg, bool prefer_busy_poll, u16 budget)
static void __napi_busy_loop(unsigned int napi_id,
bool (*loop_end)(void *, unsigned long),
void *loop_end_arg, unsigned flags, u16 budget)
{
unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
int (*napi_poll)(struct napi_struct *napi, int budget);
void *have_poll_lock = NULL;
struct napi_struct *napi;
WARN_ON_ONCE(!rcu_read_lock_held());
restart:
napi_poll = NULL;
rcu_read_lock();
napi = napi_by_id(napi_id);
if (!napi)
goto out;
return;
if (!IS_ENABLED(CONFIG_PREEMPT_RT))
preempt_disable();
@@ -6254,14 +6258,14 @@ restart:
*/
if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
NAPIF_STATE_IN_BUSY_POLL)) {
if (prefer_busy_poll)
if (flags & NAPI_F_PREFER_BUSY_POLL)
set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
goto count;
}
if (cmpxchg(&napi->state, val,
val | NAPIF_STATE_IN_BUSY_POLL |
NAPIF_STATE_SCHED) != val) {
if (prefer_busy_poll)
if (flags & NAPI_F_PREFER_BUSY_POLL)
set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
goto count;
}
@@ -6282,11 +6286,12 @@ count:
if (unlikely(need_resched())) {
if (napi_poll)
busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
busy_poll_stop(napi, have_poll_lock, flags, budget);
if (!IS_ENABLED(CONFIG_PREEMPT_RT))
preempt_enable();
rcu_read_unlock();
cond_resched();
rcu_read_lock();
if (loop_end(loop_end_arg, start_time))
return;
goto restart;
@@ -6294,10 +6299,19 @@ count:
cpu_relax();
}
if (napi_poll)
busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
busy_poll_stop(napi, have_poll_lock, flags, budget);
if (!IS_ENABLED(CONFIG_PREEMPT_RT))
preempt_enable();
out:
}
void napi_busy_loop(unsigned int napi_id,
bool (*loop_end)(void *, unsigned long),
void *loop_end_arg, bool prefer_busy_poll, u16 budget)
{
unsigned flags = prefer_busy_poll ? NAPI_F_PREFER_BUSY_POLL : 0;
rcu_read_lock();
__napi_busy_loop(napi_id, loop_end, loop_end_arg, flags, budget);
rcu_read_unlock();
}
EXPORT_SYMBOL(napi_busy_loop);