Date: Sun, 6 Nov 2011 02:03:27 +0000 (UTC) From: Alan Cox <alc@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r227127 - head/sys/vm Message-ID: <201111060203.pA623Rdi094056@svn.freebsd.org>
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Author: alc Date: Sun Nov 6 02:03:27 2011 New Revision: 227127 URL: http://svn.freebsd.org/changeset/base/227127 Log: Wake up the page daemon in vm_page_alloc_freelist() if it couldn't allocate the requested page because too few pages are cached or free. Document the VM_ALLOC_COUNT() option to vm_page_alloc() and vm_page_alloc_freelist(). Make style changes to vm_page_alloc() and vm_page_alloc_freelist(), such as using a variable name that more closely corresponds to the comments. Modified: head/sys/vm/vm_page.c Modified: head/sys/vm/vm_page.c ============================================================================== --- head/sys/vm/vm_page.c Sun Nov 6 00:44:40 2011 (r227126) +++ head/sys/vm/vm_page.c Sun Nov 6 02:03:27 2011 (r227127) @@ -1298,6 +1298,8 @@ vm_page_cache_transfer(vm_object_t orig_ * VM_ALLOC_INTERRUPT interrupt time request * * optional allocation flags: + * VM_ALLOC_COUNT(number) the number of additional pages that the caller + * intends to allocate * VM_ALLOC_IFCACHED return page only if it is cached * VM_ALLOC_IFNOTCACHED return NULL, do not reactivate if the page * is cached @@ -1315,27 +1317,26 @@ vm_page_alloc(vm_object_t object, vm_pin struct vnode *vp = NULL; vm_object_t m_object; vm_page_t m; - int flags, page_req; + int flags, req_class; - if ((req & VM_ALLOC_NOOBJ) == 0) { - KASSERT(object != NULL, - ("vm_page_alloc: NULL object.")); + KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0), + ("vm_page_alloc: inconsistent object/req")); + if (object != NULL) VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); - } - page_req = req & VM_ALLOC_CLASS_MASK; + req_class = req & VM_ALLOC_CLASS_MASK; /* - * The pager is allowed to eat deeper into the free page list. + * The page daemon is allowed to dig deeper into the free page list. */ - if ((curproc == pageproc) && (page_req != VM_ALLOC_INTERRUPT)) - page_req = VM_ALLOC_SYSTEM; + if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) + req_class = VM_ALLOC_SYSTEM; mtx_lock(&vm_page_queue_free_mtx); if (cnt.v_free_count + cnt.v_cache_count > cnt.v_free_reserved || - (page_req == VM_ALLOC_SYSTEM && + (req_class == VM_ALLOC_SYSTEM && cnt.v_free_count + cnt.v_cache_count > cnt.v_interrupt_free_min) || - (page_req == VM_ALLOC_INTERRUPT && + (req_class == VM_ALLOC_INTERRUPT && cnt.v_free_count + cnt.v_cache_count > 0)) { /* * Allocate from the free queue if the number of free pages @@ -1383,7 +1384,7 @@ vm_page_alloc(vm_object_t object, vm_pin */ mtx_unlock(&vm_page_queue_free_mtx); atomic_add_int(&vm_pageout_deficit, - MAX((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); + max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); pagedaemon_wakeup(); return (NULL); } @@ -1391,7 +1392,6 @@ vm_page_alloc(vm_object_t object, vm_pin /* * At this point we had better have found a good page. */ - KASSERT(m != NULL, ("vm_page_alloc: missing page")); KASSERT(m->queue == PQ_NONE, ("vm_page_alloc: page %p has unexpected queue %d", m, m->queue)); @@ -1403,6 +1403,8 @@ vm_page_alloc(vm_object_t object, vm_pin ("vm_page_alloc: page %p has unexpected memattr %d", m, pmap_page_get_memattr(m))); if ((m->flags & PG_CACHED) != 0) { + KASSERT((m->flags & PG_ZERO) == 0, + ("vm_page_alloc: cached page %p is PG_ZERO", m)); KASSERT(m->valid != 0, ("vm_page_alloc: cached page %p is invalid", m)); if (m->object == object && m->pindex == pindex) @@ -1546,6 +1548,8 @@ vm_page_alloc_init(vm_page_t m) * VM_ALLOC_INTERRUPT interrupt time request * * optional allocation flags: + * VM_ALLOC_COUNT(number) the number of additional pages that the caller + * intends to allocate * VM_ALLOC_WIRED wire the allocated page * VM_ALLOC_ZERO prefer a zeroed page * @@ -1557,20 +1561,32 @@ vm_page_alloc_freelist(int flind, int re struct vnode *drop; vm_page_t m; u_int flags; - int page_req; + int req_class; + + req_class = req & VM_ALLOC_CLASS_MASK; + + /* + * The page daemon is allowed to dig deeper into the free page list. + */ + if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) + req_class = VM_ALLOC_SYSTEM; - m = NULL; - page_req = req & VM_ALLOC_CLASS_MASK; - mtx_lock(&vm_page_queue_free_mtx); /* * Do not allocate reserved pages unless the req has asked for it. */ + mtx_lock(&vm_page_queue_free_mtx); if (cnt.v_free_count + cnt.v_cache_count > cnt.v_free_reserved || - (page_req == VM_ALLOC_SYSTEM && + (req_class == VM_ALLOC_SYSTEM && cnt.v_free_count + cnt.v_cache_count > cnt.v_interrupt_free_min) || - (page_req == VM_ALLOC_INTERRUPT && - cnt.v_free_count + cnt.v_cache_count > 0)) { + (req_class == VM_ALLOC_INTERRUPT && + cnt.v_free_count + cnt.v_cache_count > 0)) m = vm_phys_alloc_freelist_pages(flind, VM_FREEPOOL_DIRECT, 0); + else { + mtx_unlock(&vm_page_queue_free_mtx); + atomic_add_int(&vm_pageout_deficit, + max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1)); + pagedaemon_wakeup(); + return (NULL); } if (m == NULL) { mtx_unlock(&vm_page_queue_free_mtx);
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