From 50e0d1e56382bd8ce9f63f26707301ae1e860eab Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Wed, 28 Sep 2011 10:50:04 +1000 Subject: [PATCH] mm: distinguish between mlocked and pinned pages Some kernel components pin user space memory (infiniband and perf) (by increasing the page count) and account that memory as "mlocked". The difference between mlocking and pinning is: A. mlocked pages are marked with PG_mlocked and are exempt from swapping. Page migration may move them around though. They are kept on a special LRU list. B. Pinned pages cannot be moved because something needs to directly access physical memory. They may not be on any LRU list. I recently saw an mlockalled process where mm->locked_vm became bigger than the virtual size of the process (!) because some memory was accounted for twice: Once when the page was mlocked and once when the Infiniband layer increased the refcount because it needt to pin the RDMA memory. This patch introduces a separate counter for pinned pages and accounts them seperately. Signed-off-by: Christoph Lameter Cc: Mike Marciniszyn Cc: Roland Dreier Cc: Sean Hefty Cc: Hugh Dickins Signed-off-by: Andrew Morton <> --- drivers/infiniband/core/umem.c | 6 +++--- drivers/infiniband/hw/ipath/ipath_user_pages.c | 6 +++--- drivers/infiniband/hw/qib/qib_user_pages.c | 4 ++-- fs/proc/task_mmu.c | 2 ++ include/linux/mm_types.h | 2 +- kernel/events/core.c | 6 +++--- 6 files changed, 14 insertions(+), 12 deletions(-) diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index cc92137b3e02..71f0c0f7df94 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -137,7 +137,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, down_write(¤t->mm->mmap_sem); - locked = npages + current->mm->locked_vm; + locked = npages + current->mm->pinned_vm; lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) { @@ -207,7 +207,7 @@ out: __ib_umem_release(context->device, umem, 0); kfree(umem); } else - current->mm->locked_vm = locked; + current->mm->pinned_vm = locked; up_write(¤t->mm->mmap_sem); if (vma_list) @@ -223,7 +223,7 @@ static void ib_umem_account(struct work_struct *work) struct ib_umem *umem = container_of(work, struct ib_umem, work); down_write(&umem->mm->mmap_sem); - umem->mm->locked_vm -= umem->diff; + umem->mm->pinned_vm -= umem->diff; up_write(&umem->mm->mmap_sem); mmput(umem->mm); kfree(umem); diff --git a/drivers/infiniband/hw/ipath/ipath_user_pages.c b/drivers/infiniband/hw/ipath/ipath_user_pages.c index cfed5399f074..dc66c4506916 100644 --- a/drivers/infiniband/hw/ipath/ipath_user_pages.c +++ b/drivers/infiniband/hw/ipath/ipath_user_pages.c @@ -79,7 +79,7 @@ static int __ipath_get_user_pages(unsigned long start_page, size_t num_pages, goto bail_release; } - current->mm->locked_vm += num_pages; + current->mm->pinned_vm += num_pages; ret = 0; goto bail; @@ -178,7 +178,7 @@ void ipath_release_user_pages(struct page **p, size_t num_pages) __ipath_release_user_pages(p, num_pages, 1); - current->mm->locked_vm -= num_pages; + current->mm->pinned_vm -= num_pages; up_write(¤t->mm->mmap_sem); } @@ -195,7 +195,7 @@ static void user_pages_account(struct work_struct *_work) container_of(_work, struct ipath_user_pages_work, work); down_write(&work->mm->mmap_sem); - work->mm->locked_vm -= work->num_pages; + work->mm->pinned_vm -= work->num_pages; up_write(&work->mm->mmap_sem); mmput(work->mm); kfree(work); diff --git a/drivers/infiniband/hw/qib/qib_user_pages.c b/drivers/infiniband/hw/qib/qib_user_pages.c index 7689e49c13c9..2bc1d2b96298 100644 --- a/drivers/infiniband/hw/qib/qib_user_pages.c +++ b/drivers/infiniband/hw/qib/qib_user_pages.c @@ -74,7 +74,7 @@ static int __qib_get_user_pages(unsigned long start_page, size_t num_pages, goto bail_release; } - current->mm->locked_vm += num_pages; + current->mm->pinned_vm += num_pages; ret = 0; goto bail; @@ -151,7 +151,7 @@ void qib_release_user_pages(struct page **p, size_t num_pages) __qib_release_user_pages(p, num_pages, 1); if (current->mm) { - current->mm->locked_vm -= num_pages; + current->mm->pinned_vm -= num_pages; up_write(¤t->mm->mmap_sem); } } diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 5afaa58a8630..6750fda3ff59 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -44,6 +44,7 @@ void task_mem(struct seq_file *m, struct mm_struct *mm) "VmPeak:\t%8lu kB\n" "VmSize:\t%8lu kB\n" "VmLck:\t%8lu kB\n" + "VmPin:\t%8lu kB\n" "VmHWM:\t%8lu kB\n" "VmRSS:\t%8lu kB\n" "VmData:\t%8lu kB\n" @@ -55,6 +56,7 @@ void task_mem(struct seq_file *m, struct mm_struct *mm) hiwater_vm << (PAGE_SHIFT-10), (total_vm - mm->reserved_vm) << (PAGE_SHIFT-10), mm->locked_vm << (PAGE_SHIFT-10), + mm->pinned_vm << (PAGE_SHIFT-10), hiwater_rss << (PAGE_SHIFT-10), total_rss << (PAGE_SHIFT-10), data << (PAGE_SHIFT-10), diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 707c2b1999e2..1615a15add8e 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -293,7 +293,7 @@ struct mm_struct { unsigned long hiwater_rss; /* High-watermark of RSS usage */ unsigned long hiwater_vm; /* High-water virtual memory usage */ - unsigned long total_vm, locked_vm, shared_vm, exec_vm; + unsigned long total_vm, locked_vm, pinned_vm, shared_vm, exec_vm; unsigned long stack_vm, reserved_vm, def_flags, nr_ptes; unsigned long start_code, end_code, start_data, end_data; unsigned long start_brk, brk, start_stack; diff --git a/kernel/events/core.c b/kernel/events/core.c index 92b8811f2234..69e5b4064b97 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3545,7 +3545,7 @@ static void perf_mmap_close(struct vm_area_struct *vma) struct ring_buffer *rb = event->rb; atomic_long_sub((size >> PAGE_SHIFT) + 1, &user->locked_vm); - vma->vm_mm->locked_vm -= event->mmap_locked; + vma->vm_mm->pinned_vm -= event->mmap_locked; rcu_assign_pointer(event->rb, NULL); mutex_unlock(&event->mmap_mutex); @@ -3626,7 +3626,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) lock_limit = rlimit(RLIMIT_MEMLOCK); lock_limit >>= PAGE_SHIFT; - locked = vma->vm_mm->locked_vm + extra; + locked = vma->vm_mm->pinned_vm + extra; if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && !capable(CAP_IPC_LOCK)) { @@ -3652,7 +3652,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) atomic_long_add(user_extra, &user->locked_vm); event->mmap_locked = extra; event->mmap_user = get_current_user(); - vma->vm_mm->locked_vm += event->mmap_locked; + vma->vm_mm->pinned_vm += event->mmap_locked; unlock: if (!ret) -- 2.39.5