Eric Lee / smarc-ti-linux-kernel

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Commit 9fb4b7cc0724f178d4b24a2a566ea1e7cb120b82

Authored by Bob Liu
Committed by Linus Torvalds
1 parent 40f23a21a8
Exists in master and in 20 other branches dlt-processor-sdk-linux-03.00.00.04, newt-ti-linux-3.12.y, processor-sdk-linux-01.00.00, processor-sdk-linux-02.00.01, smarc-ti-linux-3.12.10, smarc-ti-linux-3.12.y, smarc-ti-linux-3.14.y, smarc-ti-linux-3.15.y, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04, ti-linux-3.12.y, ti-linux-3.14.y, ti-linux-3.15.y, ti-lsk-linux-4.1.y

page_cgroup: add helper function to get swap_cgroup 

There are multiple places which need to get the swap_cgroup address, so
add a helper function:

  static struct swap_cgroup *swap_cgroup_getsc(swp_entry_t ent,
                                struct swap_cgroup_ctrl **ctrl);

to simplify the code.

Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 3 changed files with 24 additions and 40 deletions Side-by-side Diff

include/linux/page_cgroup.h
Diff comments   View file @ 9fb4b7c
... ... @@ -149,7 +149,7 @@
149 149 extern unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
150 150 unsigned short old, unsigned short new);
151 151 extern unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id);
152   -extern unsigned short lookup_swap_cgroup(swp_entry_t ent);
  152 +extern unsigned short lookup_swap_cgroup_id(swp_entry_t ent);
153 153 extern int swap_cgroup_swapon(int type, unsigned long max_pages);
154 154 extern void swap_cgroup_swapoff(int type);
155 155 #else
... ... @@ -161,7 +161,7 @@
161 161 }
162 162  
163 163 static inline
164   -unsigned short lookup_swap_cgroup(swp_entry_t ent)
  164 +unsigned short lookup_swap_cgroup_id(swp_entry_t ent)
165 165 {
166 166 return 0;
167 167 }
... ... @@ -2474,7 +2474,7 @@
2474 2474 memcg = NULL;
2475 2475 } else if (PageSwapCache(page)) {
2476 2476 ent.val = page_private(page);
2477   - id = lookup_swap_cgroup(ent);
  2477 + id = lookup_swap_cgroup_id(ent);
2478 2478 rcu_read_lock();
2479 2479 memcg = mem_cgroup_lookup(id);
2480 2480 if (memcg && !css_tryget(&memcg->css))
... ... @@ -5264,7 +5264,7 @@
5264 5264 }
5265 5265 /* There is a swap entry and a page doesn't exist or isn't charged */
5266 5266 if (ent.val && !ret &&
5267   - css_id(&mc.from->css) == lookup_swap_cgroup(ent)) {
  5267 + css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) {
5268 5268 ret = MC_TARGET_SWAP;
5269 5269 if (target)
5270 5270 target->ent = ent;
... ... @@ -334,7 +334,6 @@
334 334 unsigned short id;
335 335 };
336 336 #define SC_PER_PAGE (PAGE_SIZE/sizeof(struct swap_cgroup))
337   -#define SC_POS_MASK (SC_PER_PAGE - 1)
338 337  
339 338 /*
340 339 * SwapCgroup implements "lookup" and "exchange" operations.
... ... @@ -376,6 +375,21 @@
376 375 return -ENOMEM;
377 376 }
378 377  
  378 +static struct swap_cgroup *lookup_swap_cgroup(swp_entry_t ent,
  379 + struct swap_cgroup_ctrl **ctrlp)
  380 +{
  381 + pgoff_t offset = swp_offset(ent);
  382 + struct swap_cgroup_ctrl *ctrl;
  383 + struct page *mappage;
  384 +
  385 + ctrl = &swap_cgroup_ctrl[swp_type(ent)];
  386 + if (ctrlp)
  387 + *ctrlp = ctrl;
  388 +
  389 + mappage = ctrl->map[offset / SC_PER_PAGE];
  390 + return page_address(mappage) + offset % SC_PER_PAGE;
  391 +}
  392 +
379 393 /**
380 394 * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
381 395 * @end: swap entry to be cmpxchged
382 396  
383 397  
384 398  
... ... @@ -388,21 +402,13 @@
388 402 unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
389 403 unsigned short old, unsigned short new)
390 404 {
391   - int type = swp_type(ent);
392   - unsigned long offset = swp_offset(ent);
393   - unsigned long idx = offset / SC_PER_PAGE;
394   - unsigned long pos = offset & SC_POS_MASK;
395 405 struct swap_cgroup_ctrl *ctrl;
396   - struct page *mappage;
397 406 struct swap_cgroup *sc;
398 407 unsigned long flags;
399 408 unsigned short retval;
400 409  
401   - ctrl = &swap_cgroup_ctrl[type];
  410 + sc = lookup_swap_cgroup(ent, &ctrl);
402 411  
403   - mappage = ctrl->map[idx];
404   - sc = page_address(mappage);
405   - sc += pos;
406 412 spin_lock_irqsave(&ctrl->lock, flags);
407 413 retval = sc->id;
408 414 if (retval == old)
409 415  
410 416  
411 417  
... ... @@ -423,21 +429,13 @@
423 429 */
424 430 unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
425 431 {
426   - int type = swp_type(ent);
427   - unsigned long offset = swp_offset(ent);
428   - unsigned long idx = offset / SC_PER_PAGE;
429   - unsigned long pos = offset & SC_POS_MASK;
430 432 struct swap_cgroup_ctrl *ctrl;
431   - struct page *mappage;
432 433 struct swap_cgroup *sc;
433 434 unsigned short old;
434 435 unsigned long flags;
435 436  
436   - ctrl = &swap_cgroup_ctrl[type];
  437 + sc = lookup_swap_cgroup(ent, &ctrl);
437 438  
438   - mappage = ctrl->map[idx];
439   - sc = page_address(mappage);
440   - sc += pos;
441 439 spin_lock_irqsave(&ctrl->lock, flags);
442 440 old = sc->id;
443 441 sc->id = id;
444 442  
445 443  
... ... @@ -447,28 +445,14 @@
447 445 }
448 446  
449 447 /**
450   - * lookup_swap_cgroup - lookup mem_cgroup tied to swap entry
  448 + * lookup_swap_cgroup_id - lookup mem_cgroup id tied to swap entry
451 449 * @ent: swap entry to be looked up.
452 450 *
453 451 * Returns CSS ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
454 452 */
455   -unsigned short lookup_swap_cgroup(swp_entry_t ent)
  453 +unsigned short lookup_swap_cgroup_id(swp_entry_t ent)
456 454 {
457   - int type = swp_type(ent);
458   - unsigned long offset = swp_offset(ent);
459   - unsigned long idx = offset / SC_PER_PAGE;
460   - unsigned long pos = offset & SC_POS_MASK;
461   - struct swap_cgroup_ctrl *ctrl;
462   - struct page *mappage;
463   - struct swap_cgroup *sc;
464   - unsigned short ret;
465   -
466   - ctrl = &swap_cgroup_ctrl[type];
467   - mappage = ctrl->map[idx];
468   - sc = page_address(mappage);
469   - sc += pos;
470   - ret = sc->id;
471   - return ret;
  455 + return lookup_swap_cgroup(ent, NULL)->id;
472 456 }
473 457  
474 458 int swap_cgroup_swapon(int type, unsigned long max_pages)