From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Schermerhorn Date: Fri, 22 Aug 2008 17:10:41 -0400 Message-Id: <20080822211041.29898.63572.sendpatchset@murky.usa.hp.com> In-Reply-To: <20080822211028.29898.82599.sendpatchset@murky.usa.hp.com> References: <20080822211028.29898.82599.sendpatchset@murky.usa.hp.com> Subject: [PATCH 2/7] Mlock: backout locked_vm adjustment during mmap() Sender: owner-linux-mm@kvack.org Return-Path: To: akpm@linux-foundation.org Cc: riel@redhat.com, linux-mm , kosaki.motohiro@jp.fujitsu.com, Eric.Whitney@hp.com List-ID: Against: 2.6.27-rc3-mmotm-080821-0003 can be folded into: mmap-handle-mlocked-pages-during-map-remap-unmap.patch Backout mmap() path locked_vm accounting adjustment from the "handle mlocked pages during map/remap/unmap" patch. Will resubmit as separate patch with its own description. Signed-off-by: KOSAKI Motohiro Signed-off-by: Lee Schermerhorn mm/mlock.c | 19 ++++++------------- mm/mmap.c | 19 ++++++++----------- 2 files changed, 14 insertions(+), 24 deletions(-) Index: linux-2.6.27-rc3-mmotm/mm/mlock.c =================================================================== --- linux-2.6.27-rc3-mmotm.orig/mm/mlock.c 2008-08-18 12:38:20.000000000 -0400 +++ linux-2.6.27-rc3-mmotm/mm/mlock.c 2008-08-18 12:44:16.000000000 -0400 @@ -246,7 +246,7 @@ int mlock_vma_pages_range(struct vm_area unsigned long start, unsigned long end) { struct mm_struct *mm = vma->vm_mm; - int nr_pages = (end - start) / PAGE_SIZE; + int error = 0; BUG_ON(!(vma->vm_flags & VM_LOCKED)); /* @@ -259,8 +259,7 @@ int mlock_vma_pages_range(struct vm_area is_vm_hugetlb_page(vma) || vma == get_gate_vma(current))) { downgrade_write(&mm->mmap_sem); - nr_pages = __mlock_vma_pages_range(vma, start, end, 1); - + error = __mlock_vma_pages_range(vma, start, end, 1); up_read(&mm->mmap_sem); /* vma can change or disappear */ down_write(&mm->mmap_sem); @@ -268,22 +267,20 @@ int mlock_vma_pages_range(struct vm_area /* non-NULL vma must contain @start, but need to check @end */ if (!vma || end > vma->vm_end) return -EAGAIN; - return nr_pages; + return error; } /* * User mapped kernel pages or huge pages: * make these pages present to populate the ptes, but - * fall thru' to reset VM_LOCKED--no need to unlock, and - * return nr_pages so these don't get counted against task's - * locked limit. huge pages are already counted against - * locked vm limit. + * fall thru' to reset VM_LOCKED so we don't try to munlock + * this vma during munmap()/munlock(). */ make_pages_present(start, end); no_mlock: vma->vm_flags &= ~VM_LOCKED; /* and don't come back! */ - return nr_pages; /* pages NOT mlocked */ + return error; } @@ -372,10 +369,6 @@ success: downgrade_write(&mm->mmap_sem); ret = __mlock_vma_pages_range(vma, start, end, 1); - if (ret > 0) { - mm->locked_vm -= ret; - ret = 0; - } /* * Need to reacquire mmap sem in write mode, as our callers * expect this. We have no support for atomically upgrading Index: linux-2.6.27-rc3-mmotm/mm/mmap.c =================================================================== --- linux-2.6.27-rc3-mmotm.orig/mm/mmap.c 2008-08-18 12:38:20.000000000 -0400 +++ linux-2.6.27-rc3-mmotm/mm/mmap.c 2008-08-18 12:52:21.000000000 -0400 @@ -1224,10 +1224,10 @@ out: /* * makes pages present; downgrades, drops, reacquires mmap_sem */ - int nr_pages = mlock_vma_pages_range(vma, addr, addr + len); - if (nr_pages < 0) - return nr_pages; /* vma gone! */ - mm->locked_vm += (len >> PAGE_SHIFT) - nr_pages; + int error = mlock_vma_pages_range(vma, addr, addr + len); + if (error < 0) + return error; /* vma gone! */ + mm->locked_vm += (len >> PAGE_SHIFT); } else if ((flags & MAP_POPULATE) && !(flags & MAP_NONBLOCK)) make_pages_present(addr, addr + len); return addr; @@ -1702,8 +1702,7 @@ find_extend_vma(struct mm_struct *mm, un if (!prev || expand_stack(prev, addr)) return NULL; if (prev->vm_flags & VM_LOCKED) { - int nr_pages = mlock_vma_pages_range(prev, addr, prev->vm_end); - if (nr_pages < 0) + if (mlock_vma_pages_range(prev, addr, prev->vm_end) < 0) return NULL; /* vma gone! */ } return prev; @@ -1732,8 +1731,7 @@ find_extend_vma(struct mm_struct * mm, u if (expand_stack(vma, addr)) return NULL; if (vma->vm_flags & VM_LOCKED) { - int nr_pages = mlock_vma_pages_range(vma, addr, start); - if (nr_pages < 0) + if (mlock_vma_pages_range(vma, addr, start) < 0) return NULL; /* vma gone! */ } return vma; @@ -2068,9 +2066,8 @@ unsigned long do_brk(unsigned long addr, out: mm->total_vm += len >> PAGE_SHIFT; if (flags & VM_LOCKED) { - int nr_pages = mlock_vma_pages_range(vma, addr, addr + len); - if (nr_pages >= 0) - mm->locked_vm += (len >> PAGE_SHIFT) - nr_pages; + if (mlock_vma_pages_range(vma, addr, addr + len) >= 0) + mm->locked_vm += (len >> PAGE_SHIFT); } return addr; } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org