Yoann Congal 08169cc8e1 printk: Fix LOG_CPU_MAX_BUF_SHIFT when BASE_SMALL is enabled ... [ Upstream commit 320bf43190 ] LOG_CPU_MAX_BUF_SHIFT default value depends on BASE_SMALL: config LOG_CPU_MAX_BUF_SHIFT default 12 if !BASE_SMALL default 0 if BASE_SMALL But, BASE_SMALL is a config of type int and "!BASE_SMALL" is always evaluated to true whatever is the value of BASE_SMALL. This patch fixes this by using the correct conditional operator for int type : BASE_SMALL != 0. Note: This changes CONFIG_LOG_CPU_MAX_BUF_SHIFT=12 to CONFIG_LOG_CPU_MAX_BUF_SHIFT=0 for BASE_SMALL defconfigs, but that will not be a big impact due to this code in kernel/printk/printk.c: /* by default this will only continue through for large > 64 CPUs */ if (cpu_extra <= __LOG_BUF_LEN / 2) return; Systems using CONFIG_BASE_SMALL and having 64+ CPUs should be quite rare. John Ogness <john.ogness@linutronix.de> (printk reviewer) wrote: > For printk this will mean that BASE_SMALL systems were probably > previously allocating/using the dynamic ringbuffer and now they will > just continue to use the static ringbuffer. Which is fine and saves > memory (as it should). Petr Mladek <pmladek@suse.com> (printk maintainer) wrote: > More precisely, it allocated the buffer dynamically when the sum > of per-CPU-extra space exceeded half of the default static ring > buffer. This happened for systems with more than 64 CPUs with > the default config values. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Closes: https://lore.kernel.org/all/CAMuHMdWm6u1wX7efZQf=2XUAHascps76YQac6rdnQGhc8nop_Q@mail.gmail.com/ Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Closes: https://lore.kernel.org/all/f6856be8-54b7-0fa0-1d17-39632bf29ada@oracle.com/ Fixes: 4e244c10ea ("kconfig: remove unneeded symbol_empty variable") Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Yoann Congal <yoann.congal@smile.fr> Link: https://lore.kernel.org/r/20240505080343.1471198-2-yoann.congal@smile.fr Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>		2024-06-12 11:39:35 +02:00
..
.gitignore
build-version
calibrate.c
do_mounts.c	init: flush async file closing	2024-02-08 18:41:03 +01:00
do_mounts.h	init: flush async file closing	2024-02-08 18:41:03 +01:00
do_mounts_initrd.c
do_mounts_rd.c
init_task.c	rcu-tasks: Initialize data to eliminate RCU-tasks/do_exit() deadlocks	2024-02-25 14:21:43 -08:00
initramfs.c	init: open output files from cpio unpacking with O_LARGEFILE	2024-04-05 11:21:30 -07:00
Kconfig	printk: Fix LOG_CPU_MAX_BUF_SHIFT when BASE_SMALL is enabled	2024-06-12 11:39:35 +02:00
main.c	init/main.c: Fix potential static_command_line memory overflow	2024-04-13 00:59:36 +09:00
Makefile
noinitramfs.c
version-timestamp.c
version.c