The patch titled
Subject: mm: shuffle GFP_* flags
has been added to the -mm tree. Its filename is
mm-shuffle-gfp_-flags.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-shuffle-gfp_-flags.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-shuffle-gfp_-flags.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Subject: mm: shuffle GFP_* flags
GFP_KERNEL is one of the most used constant but on archs like arm with
fixed length instruction some constants are more equal than the others.
Constants with tightly packed bits can be injected directly into
instruction stream:
0: e3a00d33 mov r0, #3264 ; 0xcc0
Others require multiple instructions or even loading out of instruction
stream:
0: e3a000c0 mov r0, #192 ; 0xc0
4: e3400060 movt r0, #96 ; 0x60
Shuffle GFP_* flags so that GFP_KERNEL/GFP_ATOMIC + __GFP_ZERO bits are
close to each other.
Savings on arm configs are ~0.1%.
Link: http://lkml.kernel.org/r/20190109201838.GA9140@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/include/linux/gfp.h~mm-shuffle-gfp_-flags
+++ a/include/linux/gfp.h
@@ -24,21 +24,21 @@ struct vm_area_struct;
#define ___GFP_HIGH 0x20u
#define ___GFP_IO 0x40u
#define ___GFP_FS 0x80u
-#define ___GFP_WRITE 0x100u
-#define ___GFP_NOWARN 0x200u
-#define ___GFP_RETRY_MAYFAIL 0x400u
-#define ___GFP_NOFAIL 0x800u
-#define ___GFP_NORETRY 0x1000u
-#define ___GFP_MEMALLOC 0x2000u
-#define ___GFP_COMP 0x4000u
-#define ___GFP_ZERO 0x8000u
-#define ___GFP_NOMEMALLOC 0x10000u
-#define ___GFP_HARDWALL 0x20000u
-#define ___GFP_THISNODE 0x40000u
-#define ___GFP_ATOMIC 0x80000u
-#define ___GFP_ACCOUNT 0x100000u
-#define ___GFP_DIRECT_RECLAIM 0x200000u
-#define ___GFP_KSWAPD_RECLAIM 0x400000u
+#define ___GFP_ZERO 0x100u
+#define ___GFP_ATOMIC 0x200u
+#define ___GFP_DIRECT_RECLAIM 0x400u
+#define ___GFP_KSWAPD_RECLAIM 0x800u
+#define ___GFP_WRITE 0x1000u
+#define ___GFP_NOWARN 0x2000u
+#define ___GFP_RETRY_MAYFAIL 0x4000u
+#define ___GFP_NOFAIL 0x8000u
+#define ___GFP_NORETRY 0x10000u
+#define ___GFP_MEMALLOC 0x20000u
+#define ___GFP_COMP 0x40000u
+#define ___GFP_NOMEMALLOC 0x80000u
+#define ___GFP_HARDWALL 0x100000u
+#define ___GFP_THISNODE 0x200000u
+#define ___GFP_ACCOUNT 0x400000u
#ifdef CONFIG_LOCKDEP
#define ___GFP_NOLOCKDEP 0x800000u
#else
_
Patches currently in -mm which might be from adobriyan@xxxxxxxxx are
proc-fix-proc-net-after-setns2.patch
proc-fix-proc-net-after-setns2-v2.patch
mm-shuffle-gfp_-flags.patch
proc-return-exit-code-4-for-skipped-tests.patch
