[PATCH 5/6] mm: Replace PF_MEMALLOC_NOIO with memalloc_nocma

Matthew Wilcox (Oracle)
2020-06-25T11:32:21Z

We're short on PF_* flags, so make memalloc_nocma its own bit where we
have plenty of space.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
include/linux/sched.h | 2 +-
include/linux/sched/mm.h | 15 +++++++--------
2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index eaf36ae1fde2..90336850e940 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -803,6 +803,7 @@ struct task_struct {
#endif
unsigned memalloc_noio:1;
unsigned memalloc_nofs:1;
+ unsigned memalloc_nocma:1;

unsigned long atomic_flags; /* Flags requiring atomic access. */

@@ -1514,7 +1515,6 @@ extern struct pid *cad_pid;
#define PF_UMH 0x02000000 /* I'm an Usermodehelper process */
#define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */
#define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
-#define PF_MEMALLOC_NOCMA 0x10000000 /* All allocation request will have _GFP_MOVABLE cleared */
#define PF_IO_WORKER 0x20000000 /* Task is an IO worker */
#define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
#define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index 08bc9d0606a8..6f7b59a848a6 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -175,12 +175,11 @@ static inline bool in_vfork(struct task_struct *tsk)

/*
* Applies per-task gfp context to the given allocation flags.
- * PF_MEMALLOC_NOCMA implies no allocation from CMA region.
*/
static inline gfp_t current_gfp_context(gfp_t flags)
{
- if (unlikely((current->flags & PF_MEMALLOC_NOCMA) ||
- current->memalloc_noio || current->memalloc_nofs)) {
+ if (unlikely(current->memalloc_noio || current->memalloc_nofs ||
+ current->memalloc_nocma)) {
/*
* NOIO implies both NOIO and NOFS and it is a weaker context
* so always make sure it makes precedence
@@ -190,7 +189,8 @@ static inline gfp_t current_gfp_context(gfp_t flags)
else if (current->memalloc_nofs)
flags &= ~__GFP_FS;
#ifdef CONFIG_CMA
- if (current->flags & PF_MEMALLOC_NOCMA)
+ /* memalloc_nocma implies no allocation from movable region */
+ if (current->memalloc_nocma)
flags &= ~__GFP_MOVABLE;
#endif
}
@@ -286,15 +286,14 @@ static inline void memalloc_noreclaim_restore(unsigned int flags)
#ifdef CONFIG_CMA
static inline unsigned int memalloc_nocma_save(void)
{
- unsigned int flags = current->flags & PF_MEMALLOC_NOCMA;
-
- current->flags |= PF_MEMALLOC_NOCMA;
+ unsigned int flags = current->memalloc_nocma;
+ current->memalloc_nocma = 1;
return flags;
}

static inline void memalloc_nocma_restore(unsigned int flags)
{
- current->flags = (current->flags & ~PF_MEMALLOC_NOCMA) | flags;
+ current->memalloc_nocma = flags ? 1 : 0;
}
#else
static inline unsigned int memalloc_nocma_save(void)
--
2.27.0