A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-29 11:11:45 -04:00
Code Issues Projects Releases Packages Wiki Activity

mm: optimize put_mems_allowed() usage

Browse source 
Since put_mems_allowed() is strictly optional, its a seqcount retry, we
don't need to evaluate the function if the allocation was in fact
successful, saving a smp_rmb some loads and comparisons on some relative
fast-paths.

Since the naming, get/put_mems_allowed() does suggest a mandatory
pairing, rename the interface, as suggested by Mel, to resemble the
seqcount interface.

This gives us: read_mems_allowed_begin() and read_mems_allowed_retry(),
where it is important to note that the return value of the latter call
is inverted from its previous incarnation.

Signed-off-by: Peter Zijlstra <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Mel Gorman 2014-04-03 14:47:24 -07:00 • committed by Linus Torvalds
commit d26914d117
8 changed files with 38 additions and 39 deletions
Download patch file Download diff file Expand all files Collapse all files

12
mm/mempolicy.c
View file

@ -1899,7 +1899,7 @@ int node_random(const nodemask_t *maskp)
* If the effective policy is 'BIND, returns a pointer to the mempolicy's
* @nodemask for filtering the zonelist.
*
* Must be protected by get_mems_allowed()
* Must be protected by read_mems_allowed_begin()
*/
struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
gfp_t gfp_flags, struct mempolicy **mpol,
@ -2063,7 +2063,7 @@ alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
retry_cpuset:
pol = get_vma_policy(current, vma, addr);
cpuset_mems_cookie = get_mems_allowed();
cpuset_mems_cookie = read_mems_allowed_begin();
if (unlikely(pol->mode == MPOL_INTERLEAVE)) {
unsigned nid;
@ -2071,7 +2071,7 @@ retry_cpuset:
nid = interleave_nid(pol, vma, addr, PAGE_SHIFT + order);
mpol_cond_put(pol);
page = alloc_page_interleave(gfp, order, nid);
if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
goto retry_cpuset;
return page;
@ -2081,7 +2081,7 @@ retry_cpuset:
policy_nodemask(gfp, pol));
if (unlikely(mpol_needs_cond_ref(pol)))
__mpol_put(pol);
if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
goto retry_cpuset;
return page;
}
@ -2115,7 +2115,7 @@ struct page *alloc_pages_current(gfp_t gfp, unsigned order)
pol = &default_policy;
retry_cpuset:
cpuset_mems_cookie = get_mems_allowed();
cpuset_mems_cookie = read_mems_allowed_begin();
/*
* No reference counting needed for current->mempolicy
@ -2128,7 +2128,7 @@ retry_cpuset:
policy_zonelist(gfp, pol, numa_node_id()),
policy_nodemask(gfp, pol));
if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
goto retry_cpuset;
return page;