user/sven/linux.git/include/linux/gfp.h, branch v3.14.29

mm: fix GFP_THISNODE callers and clarify

2014-03-11T00:26:19Z

GFP_THISNODE is for callers that implement their own clever fallback to remote nodes. It restricts the allocation to the specified node and does not invoke reclaim, assuming that the caller will take care of it when the fallback fails, e.g. through a subsequent allocation request without GFP_THISNODE set. However, many current GFP_THISNODE users only want the node exclusive aspect of the flag, without actually implementing their own fallback or triggering reclaim if necessary. This results in things like page migration failing prematurely even when there is easily reclaimable memory available, unless kswapd happens to be running already or a concurrent allocation attempt triggers the necessary reclaim. Convert all callsites that don't implement their own fallback strategy to __GFP_THISNODE. This restricts the allocation a single node too, but at the same time allows the allocator to enter the slowpath, wake kswapd, and invoke direct reclaim if necessary, to make the allocation happen when memory is full. Signed-off-by: Johannes Weiner Acked-by: Rik van Riel Cc: Jan Stancek Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGE

2014-01-24T00:36:50Z

Most of the VM_BUG_ON assertions are performed on a page. Usually, when one of these assertions fails we'll get a BUG_ON with a call stack and the registers. I've recently noticed based on the requests to add a small piece of code that dumps the page to various VM_BUG_ON sites that the page dump is quite useful to people debugging issues in mm. This patch adds a VM_BUG_ON_PAGE(cond, page) which beyond doing what VM_BUG_ON() does, also dumps the page before executing the actual BUG_ON. [akpm@linux-foundation.org: fix up includes] Signed-off-by: Sasha Levin Cc: "Kirill A. Shutemov" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

include/linux/gfp.h: fix the comment for GFP_ZONE_TABLE

2013-07-09T17:33:21Z

0xc just means MOVABLE + DMA32, which results in zone DMA32. Signed-off-by: Zhang Yanfei Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: allocate kernel pages to the right memcg

2012-12-18T23:02:12Z

When a process tries to allocate a page with the __GFP_KMEMCG flag, the page allocator will call the corresponding memcg functions to validate the allocation. Tasks in the root memcg can always proceed. To avoid adding markers to the page - and a kmem flag that would necessarily follow, as much as doing page_cgroup lookups for no reason, whoever is marking its allocations with __GFP_KMEMCG flag is responsible for telling the page allocator that this is such an allocation at free_pages() time. This is done by the invocation of __free_accounted_pages() and free_accounted_pages(). Signed-off-by: Glauber Costa Acked-by: Michal Hocko Acked-by: Mel Gorman Acked-by: Kamezawa Hiroyuki Acked-by: David Rientjes Cc: Christoph Lameter Cc: Pekka Enberg Cc: Johannes Weiner Cc: Suleiman Souhlal Cc: Tejun Heo Cc: Frederic Weisbecker Cc: Greg Thelen Cc: JoonSoo Kim Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: add a __GFP_KMEMCG flag

2012-12-18T23:02:12Z

This flag is used to indicate to the callees that this allocation is a kernel allocation in process context, and should be accounted to current's memcg. Signed-off-by: Glauber Costa Acked-by: Johannes Weiner Acked-by: Rik van Riel Acked-by: Mel Gorman Acked-by: Kamezawa Hiroyuki Acked-by: Michal Hocko Acked-by: Christoph Lameter Cc: Pekka Enberg Cc: Suleiman Souhlal Cc: Tejun Heo Cc: David Rientjes Cc: Frederic Weisbecker Cc: Greg Thelen Cc: JoonSoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: add a reminder comment for __GFP_BITS_SHIFT

2012-12-13T01:38:34Z

Cc: Glauber Costa Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: use IS_ENABLED(CONFIG_NUMA) instead of NUMA_BUILD

2012-12-12T01:22:22Z

We don't need custom NUMA_BUILD anymore, since we have handy IS_ENABLED(). Signed-off-by: Kirill A. Shutemov Acked-by: KOSAKI Motohiro Acked-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Revert "revert "Revert "mm: remove __GFP_NO_KSWAPD""" and associated damage

2012-12-10T19:03:05Z

This reverts commits a50915394f1fc02c2861d3b7ce7014788aa5066e and d7c3b937bdf45f0b844400b7bf6fd3ed50bac604. This is a revert of a revert of a revert. In addition, it reverts the even older i915 change to stop using the __GFP_NO_KSWAPD flag due to the original commits in linux-next. It turns out that the original patch really was bogus, and that the original revert was the correct thing to do after all. We thought we had fixed the problem, and then reverted the revert, but the problem really is fundamental: waking up kswapd simply isn't the right thing to do, and direct reclaim sometimes simply _is_ the right thing to do. When certain allocations fail, we simply should try some direct reclaim, and if that fails, fail the allocation. That's the right thing to do for THP allocations, which can easily fail, and the GPU allocations want to do that too. So starting kswapd is sometimes simply wrong, and removing the flag that said "don't start kswapd" was a mistake. Let's hope we never revisit this mistake again - and certainly not this many times ;) Acked-by: Mel Gorman Acked-by: Johannes Weiner Cc: Rik van Riel Cc: Andrew Morton Signed-off-by: Linus Torvalds

revert "Revert "mm: remove __GFP_NO_KSWAPD""

2012-11-30T16:51:17Z

It apepars that this patch was innocent, and we hope that "mm: avoid waking kswapd for THP allocations when compaction is deferred or contended" will fix the final kswapd-spinning cause. Cc: Zdenek Kabelac Cc: Seth Jennings Cc: Valdis Kletnieks Cc: Jiri Slaby Cc: Rik van Riel Cc: Robert Jennings Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Revert "mm: remove __GFP_NO_KSWAPD"

2012-11-27T01:41:24Z

With "mm: vmscan: scale number of pages reclaimed by reclaim/compaction based on failures" reverted, Zdenek Kabelac reported the following Hmm, so it's just took longer to hit the problem and observe kswapd0 spinning on my CPU again - it's not as endless like before - but still it easily eats minutes - it helps to turn off Firefox or TB (memory hungry apps) so kswapd0 stops soon - and restart those apps again. (And I still have like >1GB of cached memory) kswapd0 R running task 0 30 2 0x00000000 Call Trace: preempt_schedule+0x42/0x60 _raw_spin_unlock+0x55/0x60 put_super+0x31/0x40 drop_super+0x22/0x30 prune_super+0x149/0x1b0 shrink_slab+0xba/0x510 The sysrq+m indicates the system has no swap so it'll never reclaim anonymous pages as part of reclaim/compaction. That is one part of the problem but not the root cause as file-backed pages could also be reclaimed. The likely underlying problem is that kswapd is woken up or kept awake for each THP allocation request in the page allocator slow path. If compaction fails for the requesting process then compaction will be deferred for a time and direct reclaim is avoided. However, if there are a storm of THP requests that are simply rejected, it will still be the the case that kswapd is awake for a prolonged period of time as pgdat->kswapd_max_order is updated each time. This is noticed by the main kswapd() loop and it will not call kswapd_try_to_sleep(). Instead it will loopp, shrinking a small number of pages and calling shrink_slab() on each iteration. The temptation is to supply a patch that checks if kswapd was woken for THP and if so ignore pgdat->kswapd_max_order but it'll be a hack and not backed up by proper testing. As 3.7 is very close to release and this is not a bug we should release with, a safer path is to revert "mm: remove __GFP_NO_KSWAPD" for now and revisit it with the view to ironing out the balance_pgdat() logic in general. Signed-off-by: Mel Gorman Cc: Zdenek Kabelac Cc: Seth Jennings Cc: Valdis Kletnieks Cc: Jiri Slaby Cc: Rik van Riel Cc: Robert Jennings Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds