diff options
| author | Davidlohr Bueso <dave@stgolabs.net> | 2015-04-16 12:49:15 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-17 09:04:11 -0400 |
| commit | fd89a65f155fa890c0130139dfb91684d6da4cfb (patch) | |
| tree | c0bc5d80caeaa4f7863205acb59c43db66f57da9 | |
| parent | 11163348a23cdbcdca5fb42485418e75f8566a5c (diff) | |
powerpc/oprofile: reduce mmap_sem hold for exe_file
In the future mm->exe_file will be done without mmap_sem serialization,
thus isolate and reorganize the related code to make the transition
easier. Good users will, make use of the more standard get_mm_exe_file(),
requiring only holding the mmap_sem to read the value, and relying on
reference counting to make sure that the exe file won't dissappear
underneath us while getting the dcookie.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Robert Richter <rric@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | arch/powerpc/oprofile/cell/spu_task_sync.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/arch/powerpc/oprofile/cell/spu_task_sync.c b/arch/powerpc/oprofile/cell/spu_task_sync.c index 1c27831df1ac..ed7b0977072a 100644 --- a/arch/powerpc/oprofile/cell/spu_task_sync.c +++ b/arch/powerpc/oprofile/cell/spu_task_sync.c @@ -22,6 +22,7 @@ #include <linux/kref.h> #include <linux/mm.h> #include <linux/fs.h> +#include <linux/file.h> #include <linux/module.h> #include <linux/notifier.h> #include <linux/numa.h> @@ -322,18 +323,20 @@ get_exec_dcookie_and_offset(struct spu *spu, unsigned int *offsetp, unsigned long app_cookie = 0; unsigned int my_offset = 0; struct vm_area_struct *vma; + struct file *exe_file; struct mm_struct *mm = spu->mm; if (!mm) goto out; - down_read(&mm->mmap_sem); - - if (mm->exe_file) { - app_cookie = fast_get_dcookie(&mm->exe_file->f_path); - pr_debug("got dcookie for %pD\n", mm->exe_file); + exe_file = get_mm_exe_file(mm); + if (exe_file) { + app_cookie = fast_get_dcookie(&exe_file->f_path); + pr_debug("got dcookie for %pD\n", exe_file); + fput(exe_file); } + down_read(&mm->mmap_sem); for (vma = mm->mmap; vma; vma = vma->vm_next) { if (vma->vm_start > spu_ref || vma->vm_end <= spu_ref) continue; |