| Message ID | 20241113015631.3105-2-quic_bqiang@quicinc.com (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Jeff Johnson |
| Headers | show |
| Series | wifi: ath11k: fixes and refactor to firmware stats related functions | expand |
Baochen Qiang <quic_bqiang@quicinc.com> writes: > We get report [1] that CPU is running a hot loop in > ath11k_debugfs_fw_stats_request(): > > 94.60% 0.00% i3status [kernel.kallsyms] [k] do_syscall_64 > | > --94.60%--do_syscall_64 > | > --94.55%--__sys_sendmsg > ___sys_sendmsg > ____sys_sendmsg > netlink_sendmsg > netlink_unicast > genl_rcv > netlink_rcv_skb > genl_rcv_msg > | > --94.55%--genl_family_rcv_msg_dumpit > __netlink_dump_start > netlink_dump > genl_dumpit > nl80211_dump_station > | > --94.55%--ieee80211_dump_station > sta_set_sinfo > | > --94.55%--ath11k_mac_op_sta_statistics > ath11k_debugfs_get_fw_stats > | > --94.55%--ath11k_debugfs_fw_stats_request > | > |--41.73%--_raw_spin_lock_bh > | > |--22.74%--__local_bh_enable_ip > | > |--9.22%--_raw_spin_unlock_bh > | > --6.66%--srso_alias_safe_ret > > This is because, if for whatever reason ar->fw_stats_done is not set by > ath11k_update_stats_event(), ath11k_debugfs_fw_stats_request() won't yield > CPU before an up to 3s timeout. > > Add 100ms sleep to avoid CPU burning. > > Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.37 > > Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices") > Reported-by: Yury Vostrikov <mon@unformed.ru> > Closes: https://lore.kernel.org/all/7324ac7a-8b7a-42a5-aa19-de52138ff638@app.fastmail.com/ # [1] > Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com> > --- > drivers/net/wireless/ath/ath11k/debugfs.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/net/wireless/ath/ath11k/debugfs.c b/drivers/net/wireless/ath/ath11k/debugfs.c > index 57281a135dd7..a5e0f2092da5 100644 > --- a/drivers/net/wireless/ath/ath11k/debugfs.c > +++ b/drivers/net/wireless/ath/ath11k/debugfs.c > @@ -207,6 +207,9 @@ static int ath11k_debugfs_fw_stats_request(struct ath11k *ar, > break; > } > spin_unlock_bh(&ar->data_lock); > + > + /* 100ms is empirical, change if required */ > + msleep(100); > } > return 0; > } Please don't reinvent the wheel. Why not just use completion instead of this ugly spinning hack?
On 11/13/2024 7:12 PM, Kalle Valo wrote: > Baochen Qiang <quic_bqiang@quicinc.com> writes: > >> We get report [1] that CPU is running a hot loop in >> ath11k_debugfs_fw_stats_request(): >> >> 94.60% 0.00% i3status [kernel.kallsyms] [k] do_syscall_64 >> | >> --94.60%--do_syscall_64 >> | >> --94.55%--__sys_sendmsg >> ___sys_sendmsg >> ____sys_sendmsg >> netlink_sendmsg >> netlink_unicast >> genl_rcv >> netlink_rcv_skb >> genl_rcv_msg >> | >> --94.55%--genl_family_rcv_msg_dumpit >> __netlink_dump_start >> netlink_dump >> genl_dumpit >> nl80211_dump_station >> | >> --94.55%--ieee80211_dump_station >> sta_set_sinfo >> | >> --94.55%--ath11k_mac_op_sta_statistics >> ath11k_debugfs_get_fw_stats >> | >> --94.55%--ath11k_debugfs_fw_stats_request >> | >> |--41.73%--_raw_spin_lock_bh >> | >> |--22.74%--__local_bh_enable_ip >> | >> |--9.22%--_raw_spin_unlock_bh >> | >> --6.66%--srso_alias_safe_ret >> >> This is because, if for whatever reason ar->fw_stats_done is not set by >> ath11k_update_stats_event(), ath11k_debugfs_fw_stats_request() won't yield >> CPU before an up to 3s timeout. >> >> Add 100ms sleep to avoid CPU burning. >> >> Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.37 >> >> Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices") >> Reported-by: Yury Vostrikov <mon@unformed.ru> >> Closes: https://lore.kernel.org/all/7324ac7a-8b7a-42a5-aa19-de52138ff638@app.fastmail.com/ # [1] >> Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com> >> --- >> drivers/net/wireless/ath/ath11k/debugfs.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/drivers/net/wireless/ath/ath11k/debugfs.c b/drivers/net/wireless/ath/ath11k/debugfs.c >> index 57281a135dd7..a5e0f2092da5 100644 >> --- a/drivers/net/wireless/ath/ath11k/debugfs.c >> +++ b/drivers/net/wireless/ath/ath11k/debugfs.c >> @@ -207,6 +207,9 @@ static int ath11k_debugfs_fw_stats_request(struct ath11k *ar, >> break; >> } >> spin_unlock_bh(&ar->data_lock); >> + >> + /* 100ms is empirical, change if required */ >> + msleep(100); >> } >> return 0; >> } > > Please don't reinvent the wheel. Why not just use completion instead of > this ugly spinning hack? previously I was thinking that a wait_for_completion() is not allowed since we are in atomic context due to spin_lock. But thinking it more I find that after changing to use completion, the spin_lock is not necessary. so thanks, will do in next version. >
diff --git a/drivers/net/wireless/ath/ath11k/debugfs.c b/drivers/net/wireless/ath/ath11k/debugfs.c index 57281a135dd7..a5e0f2092da5 100644 --- a/drivers/net/wireless/ath/ath11k/debugfs.c +++ b/drivers/net/wireless/ath/ath11k/debugfs.c @@ -207,6 +207,9 @@ static int ath11k_debugfs_fw_stats_request(struct ath11k *ar, break; } spin_unlock_bh(&ar->data_lock); + + /* 100ms is empirical, change if required */ + msleep(100); } return 0; }
We get report [1] that CPU is running a hot loop in ath11k_debugfs_fw_stats_request(): 94.60% 0.00% i3status [kernel.kallsyms] [k] do_syscall_64 | --94.60%--do_syscall_64 | --94.55%--__sys_sendmsg ___sys_sendmsg ____sys_sendmsg netlink_sendmsg netlink_unicast genl_rcv netlink_rcv_skb genl_rcv_msg | --94.55%--genl_family_rcv_msg_dumpit __netlink_dump_start netlink_dump genl_dumpit nl80211_dump_station | --94.55%--ieee80211_dump_station sta_set_sinfo | --94.55%--ath11k_mac_op_sta_statistics ath11k_debugfs_get_fw_stats | --94.55%--ath11k_debugfs_fw_stats_request | |--41.73%--_raw_spin_lock_bh | |--22.74%--__local_bh_enable_ip | |--9.22%--_raw_spin_unlock_bh | --6.66%--srso_alias_safe_ret This is because, if for whatever reason ar->fw_stats_done is not set by ath11k_update_stats_event(), ath11k_debugfs_fw_stats_request() won't yield CPU before an up to 3s timeout. Add 100ms sleep to avoid CPU burning. Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.37 Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices") Reported-by: Yury Vostrikov <mon@unformed.ru> Closes: https://lore.kernel.org/all/7324ac7a-8b7a-42a5-aa19-de52138ff638@app.fastmail.com/ # [1] Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com> --- drivers/net/wireless/ath/ath11k/debugfs.c | 3 +++ 1 file changed, 3 insertions(+)