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![Frederic Weisbecker](/assets/img/avatar_default.png)
We need to launch the usermodehelper kernel threads with the widest affinity and this is partly why we use khelper. This workqueue has unbound properties and thus a wide affinity inherited by all its children. Now khelper also has special properties that we aren't much interested in: ordered and singlethread. There is really no need about ordering as all we do is creating kernel threads. This can be done concurrently. And singlethread is a useless limitation as well. The workqueue engine already proposes generic unbound workqueues that don't share these useless properties and handle well parallel jobs. The only worrysome specific is their affinity to the node of the current CPU. It's fine for creating the usermodehelper kernel threads but those inherit this affinity for longer jobs such as requesting modules. This patch proposes to use these node affine unbound workqueues assuming that a node is sufficient to handle several parallel usermodehelper requests. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Rik van Riel <riel@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
105 lines
3.2 KiB
C
105 lines
3.2 KiB
C
#ifndef __LINUX_KMOD_H__
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#define __LINUX_KMOD_H__
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/*
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* include/linux/kmod.h
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/gfp.h>
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#include <linux/stddef.h>
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#include <linux/errno.h>
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#include <linux/compiler.h>
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#include <linux/workqueue.h>
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#include <linux/sysctl.h>
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#define KMOD_PATH_LEN 256
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#ifdef CONFIG_MODULES
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extern char modprobe_path[]; /* for sysctl */
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/* modprobe exit status on success, -ve on error. Return value
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* usually useless though. */
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extern __printf(2, 3)
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int __request_module(bool wait, const char *name, ...);
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#define request_module(mod...) __request_module(true, mod)
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#define request_module_nowait(mod...) __request_module(false, mod)
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#define try_then_request_module(x, mod...) \
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((x) ?: (__request_module(true, mod), (x)))
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#else
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static inline int request_module(const char *name, ...) { return -ENOSYS; }
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static inline int request_module_nowait(const char *name, ...) { return -ENOSYS; }
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#define try_then_request_module(x, mod...) (x)
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#endif
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struct cred;
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struct file;
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#define UMH_NO_WAIT 0 /* don't wait at all */
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#define UMH_WAIT_EXEC 1 /* wait for the exec, but not the process */
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#define UMH_WAIT_PROC 2 /* wait for the process to complete */
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#define UMH_KILLABLE 4 /* wait for EXEC/PROC killable */
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struct subprocess_info {
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struct work_struct work;
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struct completion *complete;
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char *path;
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char **argv;
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char **envp;
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int wait;
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int retval;
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int (*init)(struct subprocess_info *info, struct cred *new);
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void (*cleanup)(struct subprocess_info *info);
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void *data;
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};
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extern int
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call_usermodehelper(char *path, char **argv, char **envp, int wait);
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extern struct subprocess_info *
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call_usermodehelper_setup(char *path, char **argv, char **envp, gfp_t gfp_mask,
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int (*init)(struct subprocess_info *info, struct cred *new),
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void (*cleanup)(struct subprocess_info *), void *data);
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extern int
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call_usermodehelper_exec(struct subprocess_info *info, int wait);
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extern struct ctl_table usermodehelper_table[];
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enum umh_disable_depth {
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UMH_ENABLED = 0,
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UMH_FREEZING,
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UMH_DISABLED,
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};
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extern int __usermodehelper_disable(enum umh_disable_depth depth);
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extern void __usermodehelper_set_disable_depth(enum umh_disable_depth depth);
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static inline int usermodehelper_disable(void)
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{
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return __usermodehelper_disable(UMH_DISABLED);
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}
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static inline void usermodehelper_enable(void)
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{
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__usermodehelper_set_disable_depth(UMH_ENABLED);
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}
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extern int usermodehelper_read_trylock(void);
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extern long usermodehelper_read_lock_wait(long timeout);
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extern void usermodehelper_read_unlock(void);
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#endif /* __LINUX_KMOD_H__ */
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