Date: Sun, 18 Aug 2013 23:15:29 +0000 (UTC) From: Davide Italiano <davide@FreeBSD.org> To: src-committers@freebsd.org, svn-src-projects@freebsd.org Subject: svn commit: r254505 - in projects/umtx/sys: kern sys Message-ID: <201308182315.r7INFTiu048598@svn.freebsd.org>
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Author: davide Date: Sun Aug 18 23:15:29 2013 New Revision: 254505 URL: http://svnweb.freebsd.org/changeset/base/254505 Log: Commit the actual schedctl() implementation. Added: projects/umtx/sys/kern/kern_schedctl.c projects/umtx/sys/sys/schedctl.h Added: projects/umtx/sys/kern/kern_schedctl.c ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ projects/umtx/sys/kern/kern_schedctl.c Sun Aug 18 23:15:29 2013 (r254505) @@ -0,0 +1,195 @@ +/*- + * Copyright (c) 2013 Davide Italiano <davide@FreeBSD.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/param.h> +#include <sys/kernel.h> +#include <sys/lock.h> +#include <sys/mutex.h> +#include <sys/proc.h> +#include <sys/queue.h> +#include <sys/rwlock.h> +#include <sys/schedctl.h> +#include <sys/syscallsubr.h> +#include <sys/sysent.h> +#include <sys/sysproto.h> +#include <sys/systm.h> + +#include <vm/vm.h> +#include <vm/vm_param.h> +#include <vm/pmap.h> +#include <vm/vm_extern.h> +#include <vm/vm_kern.h> +#include <vm/vm_map.h> +#include <vm/vm_object.h> +#include <vm/vm_page.h> +#include <vm/vm_pager.h> +#include <vm/uma.h> + +#include <machine/cpufunc.h> + +static uma_zone_t shpage_zone; /* Zone from which allocate structures */ +static size_t avail_pagesize; /* size of usable page on page */ +static size_t bitmap_len; /* # of bits in allocation bitmap */ + +/* + * Public prototypes. + */ +int schedctl(struct thread *td, struct schedctl_args *uap); + +static int +schedctl_alloc_page(struct proc *p, shpage_t **ret) +{ + vm_map_t map; + vm_page_t m; + shpage_t *spg; + int error; + + spg = uma_zalloc(shpage_zone, M_ZERO | M_WAITOK); + spg->bitmap = ~0; + spg->available = bitmap_len; + + spg->shared_page_obj = vm_pager_allocate(OBJT_PHYS, 0, PAGE_SIZE, + VM_PROT_DEFAULT, 0, NULL); + VM_OBJECT_WLOCK(spg->shared_page_obj); + m = vm_page_grab(spg->shared_page_obj, 0, VM_ALLOC_RETRY | + VM_ALLOC_NOBUSY | VM_ALLOC_ZERO); + m->valid = VM_PAGE_BITS_ALL; + VM_OBJECT_WUNLOCK(spg->shared_page_obj); + spg->pageaddr = kva_alloc(PAGE_SIZE); + pmap_qenter(spg->pageaddr, &m, 1); + + /* Map in userspace */ + PROC_LOCK(p); + SLIST_INSERT_HEAD(&(p->p_shpg), spg, pg_next); + PROC_UNLOCK(p); + map = &p->p_vmspace->vm_map; + vm_object_reference(spg->shared_page_obj); + + /* XXX: is really VMFS_ANY_SPACE the right policy? */ + error = vm_map_find(map, spg->shared_page_obj, 0, &spg->usraddr, + PAGE_SIZE, VMFS_ANY_SPACE, VM_PROT_READ | VM_PROT_WRITE, + VM_PROT_READ | VM_PROT_WRITE, 0); + if (error) { + vm_object_deallocate(spg->shared_page_obj); + return (error); + } + *ret = spg; + return (0); +} + +static int +schedctl_bmp_findfirst(shpage_t *shpg) +{ + int idx; + + /* Find first bit set in the bitmap */ + idx = ffsl(shpg->bitmap) - 1; + if (idx > bitmap_len) + return (-1); + shpg->available--; + clrbit(&(shpg->bitmap), idx); + return (idx); +} + +static int +schedctl_shared_alloc(struct thread *td, vm_offset_t *usroff, + vm_offset_t *krnoff) +{ + struct proc *p; + shpage_t *sh_pg; + u_int idx; + int error; + + sh_pg = NULL; + p = curproc; + KASSERT(p != NULL, ("proc should never be NULL")); + if (!SLIST_EMPTY(&(p->p_shpg))) { + + /* + * Iterate over the set of shared pages allocated for the process. + * If this process hasn't pages allocated or they're all completely + * full, allocate a new one. + */ + SLIST_FOREACH(sh_pg, &(p->p_shpg), pg_next) { + KASSERT(sh_pg->available >= 0, ("invalid shared page counter")); + if (sh_pg->available > 0) + break; + } + } + if (sh_pg == NULL) { + error = schedctl_alloc_page(p, &sh_pg); + if (error != 0) + return (ENOMEM); + } + + /* Now were's (mostly) sure there's room for allocation. */ + KASSERT(sh_pg != NULL && sh_pg->available > 0, + ("schedctl_page_alloc: null shpg")); + idx = schedctl_bmp_findfirst(sh_pg); + KASSERT(idx != -1, ("schedctl_page_alloc: invalid bitmap index")); + *usroff = sh_pg->usraddr + (sizeof(shstate_t) * idx); + *krnoff = sh_pg->pageaddr + (sizeof(shstate_t) * idx); + return (0); +} + +static void +kern_schedctl(struct thread *td) +{ + vm_offset_t usroff, krnoff; + + if (td->td_schedctl == NULL) { + if (schedctl_shared_alloc(td, &usroff, &krnoff) != 0) + panic("schedctl: impossible set structure for thread"); + td->td_schedctl = (shstate_t *)krnoff; + td->td_schedctl->sh_state = STATE_ONCPU; + td->td_usrschedctl = (shstate_t *)usroff; + } +} + +int +sys_schedctl(struct thread *td, struct schedctl_args *uap) +{ + + KASSERT(td != NULL, ("td should never be NULL")); + kern_schedctl(td); + td->td_retval[0] = (register_t)(td->td_usrschedctl); + return (0); +} + +void +schedctl_init(void) +{ + + avail_pagesize = PAGE_SIZE - (PAGE_SIZE % sizeof(shstate_t)); + bitmap_len = avail_pagesize / sizeof(shstate_t); + shpage_zone = uma_zcreate("schedctl structures", sizeof(shpage_t), NULL, + NULL, NULL, NULL, 0, 0); +} + +/* + * XXX: SI_SUB_KMEM is the right place to call schedctl_init? + */ +SYSINIT(schedctl, SI_SUB_KMEM, SI_ORDER_ANY, schedctl_init, NULL); Added: projects/umtx/sys/sys/schedctl.h ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ projects/umtx/sys/sys/schedctl.h Sun Aug 18 23:15:29 2013 (r254505) @@ -0,0 +1,72 @@ +/*- + * Copyright (c) 2013 Davide Italiano <davide@FreeBSD.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef _SYS_SCHEDCTL_H_ +#define _SYS_SCHEDCTL_H_ + +#include <sys/lock.h> +#include <sys/rwlock.h> + +#include <vm/vm.h> +#include <vm/vm_param.h> +#include <vm/pmap.h> +#include <vm/vm_extern.h> +#include <vm/vm_kern.h> +#include <vm/vm_object.h> + +/* + * Thread possible states. + */ +#define STATE_FREE 0x01 +#define STATE_ONCPU 0x02 +#define STATE_OFFCPU 0x04 + +/* XXX: what is the proper 'pad' size? */ +struct state_shared { + volatile int sh_state; + char pad[CACHE_LINE_SIZE - sizeof(int)]; +} __aligned(CACHE_LINE_SIZE); + +struct page_shared { + long bitmap; + int available; + vm_object_t shared_page_obj; + vm_offset_t pageaddr; + vm_offset_t usraddr; + SLIST_ENTRY(page_shared) pg_next; +}; + +typedef struct state_shared shstate_t; +typedef struct page_shared shpage_t; + +/* + * Function prototypes. + */ +void schedctl_init(void); +void schedctl_thread_cleanup(struct thread *); +void schedctl_proc_cleanup(void); + +#endif /* _SYS_SCHEDCTL_H_ */
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