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| author | Lance Yang <ioworker0@gmail.com> | 2024-03-19 14:19:43 +0000 |
|---|---|---|
| committer | Michael Knyszek <mknyszek@google.com> | 2024-03-19 14:54:29 +0000 |
| commit | cb12198de57db6f514d7ef11839d446189e38f4b (patch) | |
| tree | badaa98ce8212fb9d331bee245c0abba19e0d420 /src/internal/runtime/syscall | |
| parent | b750841906c84e894dfa3ee43e0f65d94f989b01 (diff) | |
| download | go-cb12198de57db6f514d7ef11839d446189e38f4b.tar.xz | |
runtime: optimize permission changes with mprotect
On Linux, both mprotect() and mmap() acquire the mmap_lock (in writer mode),
posing scalability challenges.
The mmap_lock (formerly called mmap_sem) is a reader/writer lock that controls
access to a process's address space; before making changes there (mapping in a
new range, for example), the kernel must acquire that lock.
Page-fault handling must also acquire mmap_lock (in reader mode) to ensure that
the address space doesn't change in surprising ways while a fault is being resolved.
A process can have a large address space and many threads running (and incurring
page faults) concurrently, turning mmap_lock into a significant bottleneck.
While both mmap() and mprotect() are protected by the mmap_lock, the shorter
duration of mprotect system call, due to their simpler nature, results in a reduced
locking time for the mmap_lock.
Change-Id: I7f929544904e31eab34d0d8a9e368abe4de64637
GitHub-Last-Rev: 6f27a216b4fb789181d00316561b44358a118b19
GitHub-Pull-Request: golang/go#65038
Reviewed-on: https://go-review.googlesource.com/c/go/+/554935
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Mauri de Souza Meneguzzo <mauri870@gmail.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Diffstat (limited to 'src/internal/runtime/syscall')
10 files changed, 10 insertions, 0 deletions
diff --git a/src/internal/runtime/syscall/defs_linux_386.go b/src/internal/runtime/syscall/defs_linux_386.go index 613dc77d59..68e687fb14 100644 --- a/src/internal/runtime/syscall/defs_linux_386.go +++ b/src/internal/runtime/syscall/defs_linux_386.go @@ -6,6 +6,7 @@ package syscall const ( SYS_FCNTL = 55 + SYS_MPROTECT = 125 SYS_EPOLL_CTL = 255 SYS_EPOLL_PWAIT = 319 SYS_EPOLL_CREATE1 = 329 diff --git a/src/internal/runtime/syscall/defs_linux_amd64.go b/src/internal/runtime/syscall/defs_linux_amd64.go index 2ba3128813..ec480f5817 100644 --- a/src/internal/runtime/syscall/defs_linux_amd64.go +++ b/src/internal/runtime/syscall/defs_linux_amd64.go @@ -5,6 +5,7 @@ package syscall const ( + SYS_MPROTECT = 10 SYS_FCNTL = 72 SYS_EPOLL_CTL = 233 SYS_EPOLL_PWAIT = 281 diff --git a/src/internal/runtime/syscall/defs_linux_arm.go b/src/internal/runtime/syscall/defs_linux_arm.go index af3e0510b1..c5d1503012 100644 --- a/src/internal/runtime/syscall/defs_linux_arm.go +++ b/src/internal/runtime/syscall/defs_linux_arm.go @@ -6,6 +6,7 @@ package syscall const ( SYS_FCNTL = 55 + SYS_MPROTECT = 125 SYS_EPOLL_CTL = 251 SYS_EPOLL_PWAIT = 346 SYS_EPOLL_CREATE1 = 357 diff --git a/src/internal/runtime/syscall/defs_linux_arm64.go b/src/internal/runtime/syscall/defs_linux_arm64.go index c924f6211a..f743fe31a5 100644 --- a/src/internal/runtime/syscall/defs_linux_arm64.go +++ b/src/internal/runtime/syscall/defs_linux_arm64.go @@ -9,6 +9,7 @@ const ( SYS_EPOLL_CTL = 21 SYS_EPOLL_PWAIT = 22 SYS_FCNTL = 25 + SYS_MPROTECT = 226 SYS_EPOLL_PWAIT2 = 441 SYS_EVENTFD2 = 19 diff --git a/src/internal/runtime/syscall/defs_linux_loong64.go b/src/internal/runtime/syscall/defs_linux_loong64.go index c1a5649a42..82218d1509 100644 --- a/src/internal/runtime/syscall/defs_linux_loong64.go +++ b/src/internal/runtime/syscall/defs_linux_loong64.go @@ -9,6 +9,7 @@ const ( SYS_EPOLL_CTL = 21 SYS_EPOLL_PWAIT = 22 SYS_FCNTL = 25 + SYS_MPROTECT = 226 SYS_EPOLL_PWAIT2 = 441 SYS_EVENTFD2 = 19 diff --git a/src/internal/runtime/syscall/defs_linux_mips64x.go b/src/internal/runtime/syscall/defs_linux_mips64x.go index 07c0aba539..4e0fd1f5d1 100644 --- a/src/internal/runtime/syscall/defs_linux_mips64x.go +++ b/src/internal/runtime/syscall/defs_linux_mips64x.go @@ -7,6 +7,7 @@ package syscall const ( + SYS_MPROTECT = 5010 SYS_FCNTL = 5070 SYS_EPOLL_CTL = 5208 SYS_EPOLL_PWAIT = 5272 diff --git a/src/internal/runtime/syscall/defs_linux_mipsx.go b/src/internal/runtime/syscall/defs_linux_mipsx.go index a1bb5d720a..b87a355093 100644 --- a/src/internal/runtime/syscall/defs_linux_mipsx.go +++ b/src/internal/runtime/syscall/defs_linux_mipsx.go @@ -8,6 +8,7 @@ package syscall const ( SYS_FCNTL = 4055 + SYS_MPROTECT = 4125 SYS_EPOLL_CTL = 4249 SYS_EPOLL_PWAIT = 4313 SYS_EPOLL_CREATE1 = 4326 diff --git a/src/internal/runtime/syscall/defs_linux_ppc64x.go b/src/internal/runtime/syscall/defs_linux_ppc64x.go index 78558b360f..8235edd795 100644 --- a/src/internal/runtime/syscall/defs_linux_ppc64x.go +++ b/src/internal/runtime/syscall/defs_linux_ppc64x.go @@ -8,6 +8,7 @@ package syscall const ( SYS_FCNTL = 55 + SYS_MPROTECT = 125 SYS_EPOLL_CTL = 237 SYS_EPOLL_PWAIT = 303 SYS_EPOLL_CREATE1 = 315 diff --git a/src/internal/runtime/syscall/defs_linux_riscv64.go b/src/internal/runtime/syscall/defs_linux_riscv64.go index c1a5649a42..82218d1509 100644 --- a/src/internal/runtime/syscall/defs_linux_riscv64.go +++ b/src/internal/runtime/syscall/defs_linux_riscv64.go @@ -9,6 +9,7 @@ const ( SYS_EPOLL_CTL = 21 SYS_EPOLL_PWAIT = 22 SYS_FCNTL = 25 + SYS_MPROTECT = 226 SYS_EPOLL_PWAIT2 = 441 SYS_EVENTFD2 = 19 diff --git a/src/internal/runtime/syscall/defs_linux_s390x.go b/src/internal/runtime/syscall/defs_linux_s390x.go index b539b2d22a..08073c01f0 100644 --- a/src/internal/runtime/syscall/defs_linux_s390x.go +++ b/src/internal/runtime/syscall/defs_linux_s390x.go @@ -6,6 +6,7 @@ package syscall const ( SYS_FCNTL = 55 + SYS_MPROTECT = 125 SYS_EPOLL_CTL = 250 SYS_EPOLL_PWAIT = 312 SYS_EPOLL_CREATE1 = 327 |