git: d22883d71544 - main - Remove PCPU_INC
Jason A. Harmening
jah at FreeBSD.org
Sun Mar 21 02:29:46 UTC 2021
The branch main has been updated by jah:
URL: https://cgit.FreeBSD.org/src/commit/?id=d22883d715440f743ab427396f0a87b72e724d18
commit d22883d715440f743ab427396f0a87b72e724d18
Author: Jason A. Harmening <jah at FreeBSD.org>
AuthorDate: 2021-03-10 04:43:01 +0000
Commit: Jason A. Harmening <jah at FreeBSD.org>
CommitDate: 2021-03-21 02:23:59 +0000
Remove PCPU_INC
e4b8deb22227 removed the last in-tree uses of PCPU_INC(). Its
potential benefit is also practically nonexistent. Non-x86
platforms already implement it as PCPU_ADD(..., 1), and according
to [0] there are no recent x86 processors for which the 'inc'
instruction provides a performance benefit over the equivalent
memory-operand form of the 'add' instruction. The only remaining
benefit of 'inc' is smaller instruction size, which in this case
is inconsequential given the limited number of per-CPU data consumers.
[0]: https://www.agner.org/optimize/instruction_tables.pdf
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D29308
---
sys/amd64/include/pcpu.h | 29 -----------------------------
sys/arm/include/pcpu.h | 1 -
sys/arm64/include/pcpu.h | 1 -
sys/i386/include/pcpu.h | 24 ------------------------
sys/mips/include/pcpu.h | 1 -
sys/powerpc/include/pcpu.h | 1 -
sys/riscv/include/pcpu.h | 1 -
7 files changed, 58 deletions(-)
diff --git a/sys/amd64/include/pcpu.h b/sys/amd64/include/pcpu.h
index 6326fbdae0be..dc99d4249bd2 100644
--- a/sys/amd64/include/pcpu.h
+++ b/sys/amd64/include/pcpu.h
@@ -179,34 +179,6 @@ _Static_assert(sizeof(struct monitorbuf) == 128, "2x cache line");
*__PCPU_PTR(name) += __val; \
} while (0)
-/*
- * Increments the value of the per-cpu counter name. The implementation
- * must be atomic with respect to interrupts.
- */
-#define __PCPU_INC(name) do { \
- CTASSERT(sizeof(__pcpu_type(name)) == 1 || \
- sizeof(__pcpu_type(name)) == 2 || \
- sizeof(__pcpu_type(name)) == 4 || \
- sizeof(__pcpu_type(name)) == 8); \
- if (sizeof(__pcpu_type(name)) == 1) { \
- __asm __volatile("incb %%gs:%0" \
- : "=m" (*(__pcpu_type(name) *)(__pcpu_offset(name)))\
- : "m" (*(__pcpu_type(name) *)(__pcpu_offset(name))));\
- } else if (sizeof(__pcpu_type(name)) == 2) { \
- __asm __volatile("incw %%gs:%0" \
- : "=m" (*(__pcpu_type(name) *)(__pcpu_offset(name)))\
- : "m" (*(__pcpu_type(name) *)(__pcpu_offset(name))));\
- } else if (sizeof(__pcpu_type(name)) == 4) { \
- __asm __volatile("incl %%gs:%0" \
- : "=m" (*(__pcpu_type(name) *)(__pcpu_offset(name)))\
- : "m" (*(__pcpu_type(name) *)(__pcpu_offset(name))));\
- } else if (sizeof(__pcpu_type(name)) == 8) { \
- __asm __volatile("incq %%gs:%0" \
- : "=m" (*(__pcpu_type(name) *)(__pcpu_offset(name)))\
- : "m" (*(__pcpu_type(name) *)(__pcpu_offset(name))));\
- } \
-} while (0)
-
/*
* Sets the value of the per-cpu variable name to value val.
*/
@@ -239,7 +211,6 @@ _Static_assert(sizeof(struct monitorbuf) == 128, "2x cache line");
#define PCPU_GET(member) __PCPU_GET(pc_ ## member)
#define PCPU_ADD(member, val) __PCPU_ADD(pc_ ## member, val)
-#define PCPU_INC(member) __PCPU_INC(pc_ ## member)
#define PCPU_PTR(member) __PCPU_PTR(pc_ ## member)
#define PCPU_SET(member, val) __PCPU_SET(pc_ ## member, val)
diff --git a/sys/arm/include/pcpu.h b/sys/arm/include/pcpu.h
index 4d609b10bf73..2353b1d06b17 100644
--- a/sys/arm/include/pcpu.h
+++ b/sys/arm/include/pcpu.h
@@ -136,7 +136,6 @@ set_tls(void *tls)
#define PCPU_GET(member) (get_pcpu()->pc_ ## member)
#define PCPU_ADD(member, value) (get_pcpu()->pc_ ## member += (value))
-#define PCPU_INC(member) PCPU_ADD(member, 1)
#define PCPU_PTR(member) (&get_pcpu()->pc_ ## member)
#define PCPU_SET(member,value) (get_pcpu()->pc_ ## member = (value))
diff --git a/sys/arm64/include/pcpu.h b/sys/arm64/include/pcpu.h
index ce4dc46e1609..09f6361c651c 100644
--- a/sys/arm64/include/pcpu.h
+++ b/sys/arm64/include/pcpu.h
@@ -73,7 +73,6 @@ get_curthread(void)
#define PCPU_GET(member) (pcpup->pc_ ## member)
#define PCPU_ADD(member, value) (pcpup->pc_ ## member += (value))
-#define PCPU_INC(member) PCPU_ADD(member, 1)
#define PCPU_PTR(member) (&pcpup->pc_ ## member)
#define PCPU_SET(member,value) (pcpup->pc_ ## member = (value))
diff --git a/sys/i386/include/pcpu.h b/sys/i386/include/pcpu.h
index 9e65d179dc36..a4c7968ea85f 100644
--- a/sys/i386/include/pcpu.h
+++ b/sys/i386/include/pcpu.h
@@ -169,29 +169,6 @@ _Static_assert(sizeof(struct monitorbuf) == 128, "2x cache line");
*__PCPU_PTR(name) += __val; \
} while (0)
-/*
- * Increments the value of the per-cpu counter name. The implementation
- * must be atomic with respect to interrupts.
- */
-#define __PCPU_INC(name) do { \
- CTASSERT(sizeof(__pcpu_type(name)) == 1 || \
- sizeof(__pcpu_type(name)) == 2 || \
- sizeof(__pcpu_type(name)) == 4); \
- if (sizeof(__pcpu_type(name)) == 1) { \
- __asm __volatile("incb %%fs:%0" \
- : "=m" (*(__pcpu_type(name) *)(__pcpu_offset(name)))\
- : "m" (*(__pcpu_type(name) *)(__pcpu_offset(name))));\
- } else if (sizeof(__pcpu_type(name)) == 2) { \
- __asm __volatile("incw %%fs:%0" \
- : "=m" (*(__pcpu_type(name) *)(__pcpu_offset(name)))\
- : "m" (*(__pcpu_type(name) *)(__pcpu_offset(name))));\
- } else if (sizeof(__pcpu_type(name)) == 4) { \
- __asm __volatile("incl %%fs:%0" \
- : "=m" (*(__pcpu_type(name) *)(__pcpu_offset(name)))\
- : "m" (*(__pcpu_type(name) *)(__pcpu_offset(name))));\
- } \
-} while (0)
-
/*
* Sets the value of the per-cpu variable name to value val.
*/
@@ -224,7 +201,6 @@ _Static_assert(sizeof(struct monitorbuf) == 128, "2x cache line");
#define PCPU_GET(member) __PCPU_GET(pc_ ## member)
#define PCPU_ADD(member, val) __PCPU_ADD(pc_ ## member, val)
-#define PCPU_INC(member) __PCPU_INC(pc_ ## member)
#define PCPU_PTR(member) __PCPU_PTR(pc_ ## member)
#define PCPU_SET(member, val) __PCPU_SET(pc_ ## member, val)
diff --git a/sys/mips/include/pcpu.h b/sys/mips/include/pcpu.h
index fea594729e90..879f2d8afb90 100644
--- a/sys/mips/include/pcpu.h
+++ b/sys/mips/include/pcpu.h
@@ -83,7 +83,6 @@ extern struct pcpu *pcpup;
#define PCPU_ADD(member, value) (PCPUP->pc_ ## member += (value))
#define PCPU_GET(member) (PCPUP->pc_ ## member)
-#define PCPU_INC(member) PCPU_ADD(member, 1)
#define PCPU_PTR(member) (&PCPUP->pc_ ## member)
#define PCPU_SET(member,value) (PCPUP->pc_ ## member = (value))
#define PCPU_LAZY_INC(member) (++PCPUP->pc_ ## member)
diff --git a/sys/powerpc/include/pcpu.h b/sys/powerpc/include/pcpu.h
index 31c4b2c47c70..288e12c1f2ab 100644
--- a/sys/powerpc/include/pcpu.h
+++ b/sys/powerpc/include/pcpu.h
@@ -168,7 +168,6 @@ __curthread(void)
* with respect to preemption.
*/
#define PCPU_ADD(member, value) (pcpup->pc_ ## member += (value))
-#define PCPU_INC(member) PCPU_ADD(member, 1)
#define PCPU_PTR(member) (&pcpup->pc_ ## member)
#define PCPU_SET(member,value) (pcpup->pc_ ## member = (value))
diff --git a/sys/riscv/include/pcpu.h b/sys/riscv/include/pcpu.h
index 5068596462fc..af5eb6fd5c41 100644
--- a/sys/riscv/include/pcpu.h
+++ b/sys/riscv/include/pcpu.h
@@ -79,7 +79,6 @@ get_curthread(void)
#define PCPU_GET(member) (get_pcpu()->pc_ ## member)
#define PCPU_ADD(member, value) (get_pcpu()->pc_ ## member += (value))
-#define PCPU_INC(member) PCPU_ADD(member, 1)
#define PCPU_PTR(member) (&get_pcpu()->pc_ ## member)
#define PCPU_SET(member,value) (get_pcpu()->pc_ ## member = (value))
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