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| author | Peter Zijlstra <peterz@infradead.org> | 2025-04-16 18:29:17 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2025-05-03 12:02:09 +0200 |
| commit | c042c505210dc3453f378df432c10fff3d471bc5 (patch) | |
| tree | 1d3ef6d9a73ec25e9ba97684717e60aaba4fdff4 /kernel/futex/futex.h | |
| parent | cec199c5e39bde7191a08087cc3d002ccfab31ff (diff) | |
| download | linux-next-c042c505210dc3453f378df432c10fff3d471bc5.tar.gz linux-next-c042c505210dc3453f378df432c10fff3d471bc5.zip | |
futex: Implement FUTEX2_MPOL
Extend the futex2 interface to be aware of mempolicy.
When FUTEX2_MPOL is specified and there is a MPOL_PREFERRED or
home_node specified covering the futex address, use that hash-map.
Notably, in this case the futex will go to the global node hashtable,
even if it is a PRIVATE futex.
When FUTEX2_NUMA|FUTEX2_MPOL is specified and the user specified node
value is FUTEX_NO_NODE, the MPOL lookup (as described above) will be
tried first before reverting to setting node to the local node.
[bigeasy: add CONFIG_FUTEX_MPOL, add MPOL to FUTEX2_VALID_MASK, write
the node only to user if FUTEX_NO_NODE was supplied]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250416162921.513656-18-bigeasy@linutronix.de
Diffstat (limited to 'kernel/futex/futex.h')
| -rw-r--r-- | kernel/futex/futex.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/kernel/futex/futex.h b/kernel/futex/futex.h index acc795367889..069fc2a83080 100644 --- a/kernel/futex/futex.h +++ b/kernel/futex/futex.h @@ -39,6 +39,7 @@ #define FLAGS_HAS_TIMEOUT 0x0040 #define FLAGS_NUMA 0x0080 #define FLAGS_STRICT 0x0100 +#define FLAGS_MPOL 0x0200 /* FUTEX_ to FLAGS_ */ static inline unsigned int futex_to_flags(unsigned int op) @@ -54,7 +55,7 @@ static inline unsigned int futex_to_flags(unsigned int op) return flags; } -#define FUTEX2_VALID_MASK (FUTEX2_SIZE_MASK | FUTEX2_NUMA | FUTEX2_PRIVATE) +#define FUTEX2_VALID_MASK (FUTEX2_SIZE_MASK | FUTEX2_NUMA | FUTEX2_MPOL | FUTEX2_PRIVATE) /* FUTEX2_ to FLAGS_ */ static inline unsigned int futex2_to_flags(unsigned int flags2) @@ -67,6 +68,9 @@ static inline unsigned int futex2_to_flags(unsigned int flags2) if (flags2 & FUTEX2_NUMA) flags |= FLAGS_NUMA; + if (flags2 & FUTEX2_MPOL) + flags |= FLAGS_MPOL; + return flags; } |