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a358f40600
Certain uses of "do once" functionality reside outside of fast path,
and so do not require jump label patching via static keys, making
existing DO_ONCE undesirable in such cases.
Replace uses of __section(".data.once") with DO_ONCE_LITE(_IF)?
This patch changes the return values of xfs_printk_once, printk_once,
and printk_deferred_once. Before, they returned whether the print was
performed, but now, they always return true. This is okay because the
return values of the following macros are entirely ignored throughout
the kernel:
- xfs_printk_once
- xfs_warn_once
- xfs_notice_once
- xfs_info_once
- printk_once
- pr_emerg_once
- pr_alert_once
- pr_crit_once
- pr_err_once
- pr_warn_once
- pr_notice_once
- pr_info_once
- pr_devel_once
- pr_debug_once
- printk_deferred_once
- orc_warn
Changes
v3:
- Expand commit message to explain why changing return values of
xfs_printk_once, printk_once, printk_deferred_once is benign
v2:
- Fix i386 build warnings
Signed-off-by: Tanner Love <tannerlove@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Mahesh Bandewar <maheshb@google.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
24 lines
677 B
C
24 lines
677 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_ONCE_LITE_H
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#define _LINUX_ONCE_LITE_H
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#include <linux/types.h>
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/* Call a function once. Similar to DO_ONCE(), but does not use jump label
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* patching via static keys.
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*/
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#define DO_ONCE_LITE(func, ...) \
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DO_ONCE_LITE_IF(true, func, ##__VA_ARGS__)
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#define DO_ONCE_LITE_IF(condition, func, ...) \
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({ \
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static bool __section(".data.once") __already_done; \
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bool __ret_do_once = !!(condition); \
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\
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if (unlikely(__ret_do_once && !__already_done)) { \
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__already_done = true; \
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func(__VA_ARGS__); \
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} \
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unlikely(__ret_do_once); \
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})
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#endif /* _LINUX_ONCE_LITE_H */
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