From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: [PATCH 00/13] tracing/events: Add __vstring and __assign_vstr helpers
Date: Tue, 05 Jul 2022 18:44:53 -0400 [thread overview]
Message-ID: <20220705224453.120955146@goodmis.org> (raw)
There's several places that open code the following logic:
TP_STRUCT__entry(__dynamic_array(char, msg, MSG_MAX)),
TP_fast_assign(vsnprintf(__get_str(msg), MSG_MAX, vaf->fmt, *vaf->va);)
To load a string created by variable array va_list.
The main issue with this approach is that "MSG_MAX" usage in the
__dynamic_array() portion. That actually just reserves the MSG_MAX in the
event, and even wastes space because there's dynamic meta data also saved
in the event to denote the offset and size of the dynamic array. It would
have been better to just use a static __array() field.
Instead, create __vstring() and __assign_vstr() that work like __string
and __assign_str() but instead of taking a destination string to copy,
take a format string and a va_list pointer and fill in the values.
It uses the helper:
#define __trace_event_vstr_len(fmt, va) \
({ \
va_list __ap; \
int __ret; \
\
va_copy(__ap, *(va)); \
__ret = vsnprintf(NULL, 0, fmt, __ap); \
va_end(__ap); \
\
min(__ret, TRACE_EVENT_STR_MAX); \
})
To figure out the length to store the string. It may be slightly slower as
it needs to run the vsnprintf() twice, but it now saves space on the ring
buffer, and more importantly, simplifies the code!
Steven Rostedt (Google) (13):
tracing/events: Add __vstring() and __assign_vstr() helper macros
tracing/IB/hfi1: Use the new __vstring() helper
tracing/ath: Use the new __vstring() helper
tracing/brcm: Use the new __vstring() helper
tracing/iwlwifi: Use the new __vstring() helper
usb: chipidea: tracing: Use the new __vstring() helper
xhci: tracing: Use the new __vstring() helper
USB: mtu3: tracing: Use the new __vstring() helper
usb: musb: tracing: Use the new __vstring() helper
scsi: iscsi: tracing: Use the new __vstring() helper
scsi: qla2xxx: tracing: Use the new __vstring() helper
batman-adv: tracing: Use the new __vstring() helper
mac80211: tracing: Use the new __vstring() helper
----
drivers/infiniband/hw/hfi1/trace_dbg.h | 8 ++------
drivers/net/wireless/ath/ath10k/trace.h | 14 ++++----------
drivers/net/wireless/ath/ath11k/trace.h | 7 ++-----
drivers/net/wireless/ath/ath6kl/trace.h | 14 ++++----------
drivers/net/wireless/ath/trace.h | 7 ++-----
drivers/net/wireless/ath/wil6210/trace.h | 7 ++-----
.../wireless/broadcom/brcm80211/brcmfmac/tracepoint.h | 12 ++++--------
.../brcm80211/brcmsmac/brcms_trace_brcmsmac_msg.h | 12 ++++--------
drivers/net/wireless/intel/iwlwifi/iwl-devtrace-msg.h | 12 ++++--------
drivers/usb/chipidea/trace.h | 4 ++--
drivers/usb/host/xhci-trace.h | 4 ++--
drivers/usb/mtu3/mtu3_trace.h | 4 ++--
drivers/usb/musb/musb_trace.h | 4 ++--
include/linux/trace_events.h | 18 ++++++++++++++++++
include/trace/events/iscsi.h | 4 ++--
include/trace/events/qla.h | 4 ++--
include/trace/stages/stage1_struct_define.h | 3 +++
include/trace/stages/stage2_data_offsets.h | 3 +++
include/trace/stages/stage4_event_fields.h | 3 +++
include/trace/stages/stage5_get_offsets.h | 4 ++++
include/trace/stages/stage6_event_callback.h | 7 +++++++
net/batman-adv/trace.h | 7 ++-----
net/mac80211/trace_msg.h | 6 ++----
23 files changed, 82 insertions(+), 86 deletions(-)
next reply other threads:[~2022-07-05 22:48 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-05 22:44 Steven Rostedt [this message]
2022-07-05 22:44 ` [PATCH 01/13] tracing/events: Add __vstring() and __assign_vstr() helper macros Steven Rostedt
2022-07-07 1:35 ` Chunfeng Yun
2022-07-12 18:00 ` Steven Rostedt
2022-07-13 9:41 ` Chunfeng Yun
2022-07-15 21:42 ` [PATCH 01/13 v2] " Steven Rostedt
2022-07-15 21:44 ` Steven Rostedt
2022-07-05 22:44 ` [PATCH 02/13] tracing/IB/hfi1: Use the new __vstring() helper Steven Rostedt
2022-07-06 4:20 ` kernel test robot
2022-07-05 22:44 ` [PATCH 03/13] tracing/ath: " Steven Rostedt
2022-07-05 22:44 ` Steven Rostedt
2022-07-05 22:44 ` Steven Rostedt
2022-07-08 6:45 ` Kalle Valo
2022-07-08 6:45 ` Kalle Valo
2022-07-08 6:45 ` Kalle Valo
2022-07-05 22:44 ` [PATCH 04/13] tracing/brcm: " Steven Rostedt
2022-07-06 2:35 ` kernel test robot
2022-07-06 2:50 ` Steven Rostedt
2022-07-06 2:50 ` Steven Rostedt
2022-07-06 9:09 ` Arend Van Spriel
2022-07-06 9:09 ` Arend Van Spriel
2022-07-06 11:51 ` Chen, Rong A
2022-07-08 5:02 ` Kalle Valo
2022-07-05 22:44 ` [PATCH 05/13] tracing/iwlwifi: " Steven Rostedt
2022-07-08 5:03 ` Kalle Valo
2022-07-05 22:44 ` [PATCH 06/13] usb: chipidea: tracing: " Steven Rostedt
2022-07-05 22:45 ` [PATCH 07/13] xhci: " Steven Rostedt
2022-07-05 22:45 ` [PATCH 08/13] USB: mtu3: " Steven Rostedt
2022-07-05 22:45 ` Steven Rostedt
2022-07-06 4:30 ` kernel test robot
2022-07-06 10:23 ` kernel test robot
2022-07-06 10:23 ` kernel test robot
2022-07-14 13:38 ` [PATCH 08/13 v2] " Steven Rostedt
2022-07-14 13:38 ` Steven Rostedt
2022-07-14 13:45 ` Greg Kroah-Hartman
2022-07-14 13:45 ` Greg Kroah-Hartman
2022-07-14 14:35 ` Steven Rostedt
2022-07-14 14:35 ` Steven Rostedt
2022-07-05 22:45 ` [PATCH 09/13] usb: musb: " Steven Rostedt
2022-07-05 22:45 ` [PATCH 10/13] scsi: iscsi: " Steven Rostedt
2022-07-05 22:45 ` [PATCH 11/13] scsi: qla2xxx: " Steven Rostedt
2022-07-05 22:45 ` [PATCH 12/13] batman-adv: " Steven Rostedt
2022-07-05 22:45 ` [PATCH 13/13] mac80211: " Steven Rostedt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220705224453.120955146@goodmis.org \
--to=rostedt@goodmis.org \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.