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yaml
---
r: 151532
b: refs/heads/master
c: 341ce06
h: refs/heads/master
v: v3
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Peter Zijlstra authored and Linus Torvalds committed Jun 17, 2009
1 parent 08eef5f commit cd0108d
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Showing 2 changed files with 51 additions and 45 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 3dd2826698b6902aafd9441ce28ebb44735fd0d6
refs/heads/master: 341ce06f69abfafa31b9468410a13dbd60e2b237
94 changes: 50 additions & 44 deletions trunk/mm/page_alloc.c
Original file line number Diff line number Diff line change
Expand Up @@ -1574,15 +1574,6 @@ __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
return page;
}

static inline int
is_allocation_high_priority(struct task_struct *p, gfp_t gfp_mask)
{
if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE)))
&& !in_interrupt())
return 1;
return 0;
}

/*
* This is called in the allocator slow-path if the allocation request is of
* sufficient urgency to ignore watermarks and take other desperate measures
Expand Down Expand Up @@ -1618,6 +1609,42 @@ void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
wakeup_kswapd(zone, order);
}

static inline int
gfp_to_alloc_flags(gfp_t gfp_mask)
{
struct task_struct *p = current;
int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
const gfp_t wait = gfp_mask & __GFP_WAIT;

/*
* The caller may dip into page reserves a bit more if the caller
* cannot run direct reclaim, or if the caller has realtime scheduling
* policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
* set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
*/
if (gfp_mask & __GFP_HIGH)
alloc_flags |= ALLOC_HIGH;

if (!wait) {
alloc_flags |= ALLOC_HARDER;
/*
* Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
* See also cpuset_zone_allowed() comment in kernel/cpuset.c.
*/
alloc_flags &= ~ALLOC_CPUSET;
} else if (unlikely(rt_task(p)))
alloc_flags |= ALLOC_HARDER;

if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
if (!in_interrupt() &&
((p->flags & PF_MEMALLOC) ||
unlikely(test_thread_flag(TIF_MEMDIE))))
alloc_flags |= ALLOC_NO_WATERMARKS;
}

return alloc_flags;
}

static inline struct page *
__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
struct zonelist *zonelist, enum zone_type high_zoneidx,
Expand Down Expand Up @@ -1648,56 +1675,35 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
* OK, we're below the kswapd watermark and have kicked background
* reclaim. Now things get more complex, so set up alloc_flags according
* to how we want to proceed.
*
* The caller may dip into page reserves a bit more if the caller
* cannot run direct reclaim, or if the caller has realtime scheduling
* policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
* set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
*/
alloc_flags = ALLOC_WMARK_MIN;
if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait)
alloc_flags |= ALLOC_HARDER;
if (gfp_mask & __GFP_HIGH)
alloc_flags |= ALLOC_HIGH;
if (wait)
alloc_flags |= ALLOC_CPUSET;
alloc_flags = gfp_to_alloc_flags(gfp_mask);

restart:
/*
* Go through the zonelist again. Let __GFP_HIGH and allocations
* coming from realtime tasks go deeper into reserves.
*
* This is the last chance, in general, before the goto nopage.
* Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
* See also cpuset_zone_allowed() comment in kernel/cpuset.c.
*/
/* This is the last chance, in general, before the goto nopage. */
page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
high_zoneidx, alloc_flags,
preferred_zone,
migratetype);
high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
preferred_zone, migratetype);
if (page)
goto got_pg;

rebalance:
/* Allocate without watermarks if the context allows */
if (is_allocation_high_priority(p, gfp_mask)) {
/* Do not dip into emergency reserves if specified */
if (!(gfp_mask & __GFP_NOMEMALLOC)) {
page = __alloc_pages_high_priority(gfp_mask, order,
zonelist, high_zoneidx, nodemask, preferred_zone,
migratetype);
if (page)
goto got_pg;
}

/* Ensure no recursion into the allocator */
goto nopage;
if (alloc_flags & ALLOC_NO_WATERMARKS) {
page = __alloc_pages_high_priority(gfp_mask, order,
zonelist, high_zoneidx, nodemask,
preferred_zone, migratetype);
if (page)
goto got_pg;
}

/* Atomic allocations - we can't balance anything */
if (!wait)
goto nopage;

/* Avoid recursion of direct reclaim */
if (p->flags & PF_MEMALLOC)
goto nopage;

/* Try direct reclaim and then allocating */
page = __alloc_pages_direct_reclaim(gfp_mask, order,
zonelist, high_zoneidx,
Expand Down

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