| Message ID | 20240206001333.1710070-1-yoann.congal@smile.fr |
|---|---|
| Headers | show |
| Series | printk: CONFIG_BASE_SMALL fix for LOG_CPU_MAX_BUF_SHIFT and removal of CONFIG_BASE_FULL | expand |
On Tue, Feb 6, 2024 at 9:13 AM Yoann Congal <yoann.congal@smile.fr> wrote: > > 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. > > Signed-off-by: Yoann Congal <yoann.congal@smile.fr> > 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: 4e244c10eab3 ("kconfig: remove unneeded symbol_empty variable") Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
On Tue, Feb 6, 2024 at 9:13 AM Yoann Congal <yoann.congal@smile.fr> wrote: > > CONFIG_BASE_SMALL is currently a type int but is only used as a boolean. > > So, change its type to bool and adapt all usages: > CONFIG_BASE_SMALL == 0 becomes !IS_ENABLED(CONFIG_BASE_SMALL) and > CONFIG_BASE_SMALL != 0 becomes IS_ENABLED(CONFIG_BASE_SMALL). > > Signed-off-by: Yoann Congal <yoann.congal@smile.fr> > --- > NB: This is preliminary work for the following patch removing > CONFIG_BASE_FULL (now equivalent to !CONFIG_BASE_SMALL) > > v3->v4: > * Split "switch CONFIG_BASE_SMALL to bool" (this patch) and "Remove the redundant > config" into two patches > * keep CONFIG_BASE_SMALL instead of CONFIG_BASE_FULL > --- > arch/x86/include/asm/mpspec.h | 6 +++--- > drivers/tty/vt/vc_screen.c | 2 +- > include/linux/threads.h | 4 ++-- > include/linux/udp.h | 2 +- > include/linux/xarray.h | 2 +- > init/Kconfig | 8 ++++---- > kernel/futex/core.c | 2 +- > kernel/user.c | 2 +- > 8 files changed, 14 insertions(+), 14 deletions(-) > > diff --git a/arch/x86/include/asm/mpspec.h b/arch/x86/include/asm/mpspec.h > index 4b0f98a8d338d..c01d3105840cf 100644 > --- a/arch/x86/include/asm/mpspec.h > +++ b/arch/x86/include/asm/mpspec.h > @@ -15,10 +15,10 @@ extern int pic_mode; > * Summit or generic (i.e. installer) kernels need lots of bus entries. > * Maximum 256 PCI busses, plus 1 ISA bus in each of 4 cabinets. > */ > -#if CONFIG_BASE_SMALL == 0 > -# define MAX_MP_BUSSES 260 > -#else > +#ifdef CONFIG_BASE_SMALL > # define MAX_MP_BUSSES 32 > +#else > +# define MAX_MP_BUSSES 260 > #endif > > #define MAX_IRQ_SOURCES 256 > diff --git a/drivers/tty/vt/vc_screen.c b/drivers/tty/vt/vc_screen.c > index 67e2cb7c96eec..da33c6c4691c0 100644 > --- a/drivers/tty/vt/vc_screen.c > +++ b/drivers/tty/vt/vc_screen.c > @@ -51,7 +51,7 @@ > #include <asm/unaligned.h> > > #define HEADER_SIZE 4u > -#define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE) > +#define CON_BUF_SIZE (IS_ENABLED(CONFIG_BASE_SMALL) ? 256 : PAGE_SIZE) > > /* > * Our minor space: > diff --git a/include/linux/threads.h b/include/linux/threads.h > index c34173e6c5f18..1674a471b0b4c 100644 > --- a/include/linux/threads.h > +++ b/include/linux/threads.h > @@ -25,13 +25,13 @@ > /* > * This controls the default maximum pid allocated to a process > */ > -#define PID_MAX_DEFAULT (CONFIG_BASE_SMALL ? 0x1000 : 0x8000) > +#define PID_MAX_DEFAULT (IS_ENABLED(CONFIG_BASE_SMALL) ? 0x1000 : 0x8000) > > /* > * A maximum of 4 million PIDs should be enough for a while. > * [NOTE: PID/TIDs are limited to 2^30 ~= 1 billion, see FUTEX_TID_MASK.] > */ > -#define PID_MAX_LIMIT (CONFIG_BASE_SMALL ? PAGE_SIZE * 8 : \ > +#define PID_MAX_LIMIT (IS_ENABLED(CONFIG_BASE_SMALL) ? PAGE_SIZE * 8 : \ > (sizeof(long) > 4 ? 4 * 1024 * 1024 : PID_MAX_DEFAULT)) > > /* > diff --git a/include/linux/udp.h b/include/linux/udp.h > index d04188714dca1..b456417fb4515 100644 > --- a/include/linux/udp.h > +++ b/include/linux/udp.h > @@ -24,7 +24,7 @@ static inline struct udphdr *udp_hdr(const struct sk_buff *skb) > } > > #define UDP_HTABLE_SIZE_MIN_PERNET 128 > -#define UDP_HTABLE_SIZE_MIN (CONFIG_BASE_SMALL ? 128 : 256) > +#define UDP_HTABLE_SIZE_MIN (IS_ENABLED(CONFIG_BASE_SMALL) ? 128 : 256) > #define UDP_HTABLE_SIZE_MAX 65536 > > static inline u32 udp_hashfn(const struct net *net, u32 num, u32 mask) > diff --git a/include/linux/xarray.h b/include/linux/xarray.h > index cb571dfcf4b16..3f81ee5f9fb9c 100644 > --- a/include/linux/xarray.h > +++ b/include/linux/xarray.h > @@ -1141,7 +1141,7 @@ static inline void xa_release(struct xarray *xa, unsigned long index) > * doubled the number of slots per node, we'd get only 3 nodes per 4kB page. > */ > #ifndef XA_CHUNK_SHIFT > -#define XA_CHUNK_SHIFT (CONFIG_BASE_SMALL ? 4 : 6) > +#define XA_CHUNK_SHIFT (IS_ENABLED(CONFIG_BASE_SMALL) ? 4 : 6) > #endif > #define XA_CHUNK_SIZE (1UL << XA_CHUNK_SHIFT) > #define XA_CHUNK_MASK (XA_CHUNK_SIZE - 1) > diff --git a/init/Kconfig b/init/Kconfig > index d50ebd2a2ce42..d4b16cad98502 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -734,7 +734,7 @@ config LOG_CPU_MAX_BUF_SHIFT > int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)" > depends on SMP > range 0 21 > - default 0 if BASE_SMALL != 0 > + default 0 if BASE_SMALL > default 12 > depends on PRINTK > help > @@ -1941,9 +1941,9 @@ config RT_MUTEXES > default y if PREEMPT_RT > > config BASE_SMALL > - int > - default 0 if BASE_FULL > - default 1 if !BASE_FULL > + bool > + default y if !BASE_FULL > + default n The shortest form would be: config BASE_SMALL def_bool !BASE_FULL But, that is not a big deal, as this hunk will be removed by 3/3. Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>