mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 11:19:37 +00:00
![Jann Horn](/assets/img/avatar_default.png)
The futex UAPI changed back in commit 76b81e2b0e
("[PATCH] lightweight
robust futexes updates 2"), which landed in v2.6.17: FUTEX_TID_MASK is now
0x3fffffff instead of 0x1fffffff. Update the corresponding comment in
include/linux/threads.h.
Documentation mentions that only the lower 29 bits are available for TID
storage, but as the UAPI header released the bit already via
FUTEX_TID_MASK, this is moot as well. Fix it up.
[ tglx: Fixed up documentation ]
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200302112939.8068-1-jannh@google.com
46 lines
1.3 KiB
C
46 lines
1.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _LINUX_THREADS_H
|
|
#define _LINUX_THREADS_H
|
|
|
|
|
|
/*
|
|
* The default limit for the nr of threads is now in
|
|
* /proc/sys/kernel/threads-max.
|
|
*/
|
|
|
|
/*
|
|
* Maximum supported processors. Setting this smaller saves quite a
|
|
* bit of memory. Use nr_cpu_ids instead of this except for static bitmaps.
|
|
*/
|
|
#ifndef CONFIG_NR_CPUS
|
|
/* FIXME: This should be fixed in the arch's Kconfig */
|
|
#define CONFIG_NR_CPUS 1
|
|
#endif
|
|
|
|
/* Places which use this should consider cpumask_var_t. */
|
|
#define NR_CPUS CONFIG_NR_CPUS
|
|
|
|
#define MIN_THREADS_LEFT_FOR_ROOT 4
|
|
|
|
/*
|
|
* This controls the default maximum pid allocated to a process
|
|
*/
|
|
#define PID_MAX_DEFAULT (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 : \
|
|
(sizeof(long) > 4 ? 4 * 1024 * 1024 : PID_MAX_DEFAULT))
|
|
|
|
/*
|
|
* Define a minimum number of pids per cpu. Heuristically based
|
|
* on original pid max of 32k for 32 cpus. Also, increase the
|
|
* minimum settable value for pid_max on the running system based
|
|
* on similar defaults. See kernel/pid.c:pidmap_init() for details.
|
|
*/
|
|
#define PIDS_PER_CPU_DEFAULT 1024
|
|
#define PIDS_PER_CPU_MIN 8
|
|
|
|
#endif
|