| Message ID | 20230223012258.1701175-1-jacob.e.keller@intel.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] net: add no-op for napi_busy_loop if CONFIG_NET_RX_BUSY_POLL=n | expand |
On Wed, 22 Feb 2023 17:22:58 -0800 Jacob Keller wrote: > Commit 7db6b048da3b ("net: Commonize busy polling code to focus on napi_id > instead of socket") introduced napi_busy_loop and refactored sk_busy_loop > to call this new function. The commit removed the no-op implementation of > sk_busy_loop in the #else block for CONFIG_NET_RX_BUSY_POLL, and placed the > declaration of napi_busy_poll inside the # block where sk_busy_loop used to > be declared. > > Because of this, if a module tries to use napi_busy_loop it must wrap the > use inside a IS_ENABLED(CONFIG_NET_RX_BUSY_POLL) check, as the function is > not declared when this is false. > > The original sk_busy_loop function had both a declaration and a no-op > variant when the config flag was set to N. Do the same for napi_busy_loop > by adding a no-op implementation in the #else block as expected. > > Fixes: 7db6b048da3b ("net: Commonize busy polling code to focus on napi_id instead of socket") We need a reference to which module needs this or a Kconfig snippet + build failure output.
On 2/22/2023 8:53 PM, Jakub Kicinski wrote: > On Wed, 22 Feb 2023 17:22:58 -0800 Jacob Keller wrote: >> Commit 7db6b048da3b ("net: Commonize busy polling code to focus on napi_id >> instead of socket") introduced napi_busy_loop and refactored sk_busy_loop >> to call this new function. The commit removed the no-op implementation of >> sk_busy_loop in the #else block for CONFIG_NET_RX_BUSY_POLL, and placed the >> declaration of napi_busy_poll inside the # block where sk_busy_loop used to >> be declared. >> >> Because of this, if a module tries to use napi_busy_loop it must wrap the >> use inside a IS_ENABLED(CONFIG_NET_RX_BUSY_POLL) check, as the function is >> not declared when this is false. >> >> The original sk_busy_loop function had both a declaration and a no-op >> variant when the config flag was set to N. Do the same for napi_busy_loop >> by adding a no-op implementation in the #else block as expected. >> >> Fixes: 7db6b048da3b ("net: Commonize busy polling code to focus on napi_id instead of socket") > > We need a reference to which module needs this or a Kconfig snippet > + build failure output. Hm, fair. I found this while investigating something else with code not yet submitted that uses this function in the ice driver without checking CONFIG_NET_RX_BUSY_POLL. I assumed this would be a problem somewhere else too... However, I just looked through the current tree and the only user of napi_busy_loop happens to be under a CONFIG_NET_RX_BUSY_POLL check already so I don't think this is possible to trigger with any in-tree code at present. Thanks, Jake
diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h index f90f0021f5f2..8f84f6202f1c 100644 --- a/include/net/busy_poll.h +++ b/include/net/busy_poll.h @@ -58,6 +58,13 @@ static inline bool sk_can_busy_loop(struct sock *sk) return false; } +static inline void +napi_busy_loop(unsigned int napi_id, + bool (*loop_end)(void *, unsigned long), + void *loop_end_arg, bool prefer_busy_poll, u16 budget) +{ +} + #endif /* CONFIG_NET_RX_BUSY_POLL */ static inline unsigned long busy_loop_current_time(void)
Commit 7db6b048da3b ("net: Commonize busy polling code to focus on napi_id instead of socket") introduced napi_busy_loop and refactored sk_busy_loop to call this new function. The commit removed the no-op implementation of sk_busy_loop in the #else block for CONFIG_NET_RX_BUSY_POLL, and placed the declaration of napi_busy_poll inside the # block where sk_busy_loop used to be declared. Because of this, if a module tries to use napi_busy_loop it must wrap the use inside a IS_ENABLED(CONFIG_NET_RX_BUSY_POLL) check, as the function is not declared when this is false. The original sk_busy_loop function had both a declaration and a no-op variant when the config flag was set to N. Do the same for napi_busy_loop by adding a no-op implementation in the #else block as expected. Fixes: 7db6b048da3b ("net: Commonize busy polling code to focus on napi_id instead of socket") Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> --- include/net/busy_poll.h | 7 +++++++ 1 file changed, 7 insertions(+) base-commit: 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2