android: binder: drop lru lock in isolate callback

Drop the global lru lock in isolate callback before calling
zap_page_range which calls cond_resched, and re-acquire the global lru
lock before returning.  Also change return code to LRU_REMOVED_RETRY.

Use mmput_async when fail to acquire mmap sem in an atomic context.

Fix "BUG: sleeping function called from invalid context"
errors when CONFIG_DEBUG_ATOMIC_SLEEP is enabled.

Also restore mmput_async, which was initially introduced in commit
ec8d7c14ea ("mm, oom_reaper: do not mmput synchronously from the oom
reaper context"), and was removed in commit 2129258024 ("mm: oom: let
oom_reap_task and exit_mmap run concurrently").

Link: http://lkml.kernel.org/r/20170914182231.90908-1-sherryy@android.com
Fixes: f2517eb76f ("android: binder: Add global lru shrinker to binder")
Signed-off-by: Sherry Yang <sherryy@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reported-by: Kyle Yan <kyan@codeaurora.org>
Acked-by: Arve Hjønnevåg <arve@android.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Martijn Coenen <maco@google.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Riley Andrews <riandrews@android.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Hoeun Ryu <hoeun.ryu@gmail.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Sherry Yang 2017-10-03 16:15:00 -07:00 committed by Linus Torvalds
parent 3f2eb0287e
commit a1b2289cef
3 changed files with 36 additions and 6 deletions

View File

@ -913,6 +913,7 @@ enum lru_status binder_alloc_free_page(struct list_head *item,
struct binder_alloc *alloc;
uintptr_t page_addr;
size_t index;
struct vm_area_struct *vma;
alloc = page->alloc;
if (!mutex_trylock(&alloc->mutex))
@ -923,16 +924,22 @@ enum lru_status binder_alloc_free_page(struct list_head *item,
index = page - alloc->pages;
page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE;
if (alloc->vma) {
vma = alloc->vma;
if (vma) {
mm = get_task_mm(alloc->tsk);
if (!mm)
goto err_get_task_mm_failed;
if (!down_write_trylock(&mm->mmap_sem))
goto err_down_write_mmap_sem_failed;
}
list_lru_isolate(lru, item);
spin_unlock(lock);
if (vma) {
trace_binder_unmap_user_start(alloc, index);
zap_page_range(alloc->vma,
zap_page_range(vma,
page_addr + alloc->user_buffer_offset,
PAGE_SIZE);
@ -950,13 +957,12 @@ enum lru_status binder_alloc_free_page(struct list_head *item,
trace_binder_unmap_kernel_end(alloc, index);
list_lru_isolate(lru, item);
spin_lock(lock);
mutex_unlock(&alloc->mutex);
return LRU_REMOVED;
return LRU_REMOVED_RETRY;
err_down_write_mmap_sem_failed:
mmput(mm);
mmput_async(mm);
err_get_task_mm_failed:
err_page_already_freed:
mutex_unlock(&alloc->mutex);

View File

@ -84,6 +84,12 @@ static inline bool mmget_not_zero(struct mm_struct *mm)
/* mmput gets rid of the mappings and all user-space */
extern void mmput(struct mm_struct *);
#ifdef CONFIG_MMU
/* same as above but performs the slow path from the async context. Can
* be called from the atomic context as well
*/
void mmput_async(struct mm_struct *);
#endif
/* Grab a reference to a task's mm, if it is not already going away */
extern struct mm_struct *get_task_mm(struct task_struct *task);

View File

@ -946,6 +946,24 @@ void mmput(struct mm_struct *mm)
}
EXPORT_SYMBOL_GPL(mmput);
#ifdef CONFIG_MMU
static void mmput_async_fn(struct work_struct *work)
{
struct mm_struct *mm = container_of(work, struct mm_struct,
async_put_work);
__mmput(mm);
}
void mmput_async(struct mm_struct *mm)
{
if (atomic_dec_and_test(&mm->mm_users)) {
INIT_WORK(&mm->async_put_work, mmput_async_fn);
schedule_work(&mm->async_put_work);
}
}
#endif
/**
* set_mm_exe_file - change a reference to the mm's executable file
*