Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commitd7fefcc

Browse files
kvaneeshtorvalds
authored andcommitted
mm/cma: add PF flag to force non cma alloc
Patch series "mm/kvm/vfio/ppc64: Migrate compound pages out of CMAregion", v8.ppc64 uses the CMA area for the allocation of guest page table (hashpage table). We won't be able to start guest if we fail to allocatehash page table. We have observed hash table allocation failure becausewe failed to migrate pages out of CMA region because they were pinned.This happen when we are using VFIO. VFIO on ppc64 pins the entire guestRAM. If the guest RAM pages get allocated out of CMA region, we won'tbe able to migrate those pages. The pages are also pinned for thelifetime of the guest.Currently we support migration of non-compound pages. With THP and withthe addition of hugetlb migration we can end up allocating compoundpages from CMA region. This patch series add support for migratingcompound pages.This patch (of 4):Add PF_MEMALLOC_NOCMA which make sure any allocation in that context ismarked non-movable and hence cannot be satisfied by CMA region.This is useful with get_user_pages_longterm where we want to take a pagepin by migrating pages from CMA region. Marking the sectionPF_MEMALLOC_NOCMA ensures that we avoid unnecessary page migrationlater.Link:http://lkml.kernel.org/r/20190114095438.32470-2-aneesh.kumar@linux.ibm.comSigned-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>Suggested-by: Andrea Arcangeli <aarcange@redhat.com>Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>Cc: Michal Hocko <mhocko@kernel.org>Cc: Alexey Kardashevskiy <aik@ozlabs.ru>Cc: David Gibson <david@gibson.dropbear.id.au>Cc: Michael Ellerman <mpe@ellerman.id.au>Cc: Mel Gorman <mgorman@techsingularity.net>Cc: Vlastimil Babka <vbabka@suse.cz>Signed-off-by: Andrew Morton <akpm@linux-foundation.org>Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent6e2e07c commitd7fefcc

File tree

2 files changed

+41
-8
lines changed

2 files changed

+41
-8
lines changed

‎include/linux/sched.h‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1407,6 +1407,7 @@ extern struct pid *cad_pid;
14071407
#definePF_UMH0x02000000/* I'm an Usermodehelper process */
14081408
#definePF_NO_SETAFFINITY0x04000000/* Userland is not allowed to meddle with cpus_allowed */
14091409
#definePF_MCE_EARLY0x08000000/* Early kill for mce process policy */
1410+
#definePF_MEMALLOC_NOCMA0x10000000/* All allocation request will have _GFP_MOVABLE cleared */
14101411
#definePF_MUTEX_TESTER0x20000000/* Thread belongs to the rt mutex tester */
14111412
#definePF_FREEZER_SKIP0x40000000/* Freezer should not count it as freezable */
14121413
#definePF_SUSPEND_TASK0x80000000/* This thread called freeze_processes() and should not be frozen */

‎include/linux/sched/mm.h‎

Lines changed: 40 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -148,17 +148,25 @@ static inline bool in_vfork(struct task_struct *tsk)
148148
* Applies per-task gfp context to the given allocation flags.
149149
* PF_MEMALLOC_NOIO implies GFP_NOIO
150150
* PF_MEMALLOC_NOFS implies GFP_NOFS
151+
* PF_MEMALLOC_NOCMA implies no allocation from CMA region.
151152
*/
152153
staticinlinegfp_tcurrent_gfp_context(gfp_tflags)
153154
{
154-
/*
155-
* NOIO implies both NOIO and NOFS and it is a weaker context
156-
* so always make sure it makes precedence
157-
*/
158-
if (unlikely(current->flags&PF_MEMALLOC_NOIO))
159-
flags &= ~(__GFP_IO |__GFP_FS);
160-
elseif (unlikely(current->flags&PF_MEMALLOC_NOFS))
161-
flags &= ~__GFP_FS;
155+
if (unlikely(current->flags&
156+
(PF_MEMALLOC_NOIO |PF_MEMALLOC_NOFS |PF_MEMALLOC_NOCMA))) {
157+
/*
158+
* NOIO implies both NOIO and NOFS and it is a weaker context
159+
* so always make sure it makes precedence
160+
*/
161+
if (current->flags&PF_MEMALLOC_NOIO)
162+
flags &= ~(__GFP_IO |__GFP_FS);
163+
elseif (current->flags&PF_MEMALLOC_NOFS)
164+
flags &= ~__GFP_FS;
165+
#ifdefCONFIG_CMA
166+
if (current->flags&PF_MEMALLOC_NOCMA)
167+
flags &= ~__GFP_MOVABLE;
168+
#endif
169+
}
162170
returnflags;
163171
}
164172

@@ -248,6 +256,30 @@ static inline void memalloc_noreclaim_restore(unsigned int flags)
248256
current->flags= (current->flags& ~PF_MEMALLOC) |flags;
249257
}
250258

259+
#ifdefCONFIG_CMA
260+
staticinlineunsignedintmemalloc_nocma_save(void)
261+
{
262+
unsignedintflags=current->flags&PF_MEMALLOC_NOCMA;
263+
264+
current->flags |=PF_MEMALLOC_NOCMA;
265+
returnflags;
266+
}
267+
268+
staticinlinevoidmemalloc_nocma_restore(unsignedintflags)
269+
{
270+
current->flags= (current->flags& ~PF_MEMALLOC_NOCMA) |flags;
271+
}
272+
#else
273+
staticinlineunsignedintmemalloc_nocma_save(void)
274+
{
275+
return0;
276+
}
277+
278+
staticinlinevoidmemalloc_nocma_restore(unsignedintflags)
279+
{
280+
}
281+
#endif
282+
251283
#ifdefCONFIG_MEMCG
252284
/**
253285
* memalloc_use_memcg - Starts the remote memcg charging scope.

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp