From c560e2f65b625367d3baf0fcf06cf19996407659 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Wed, 6 Nov 2024 10:25:26 +1100 Subject: [PATCH] Makefile: Don't attempt to auto-detect stack size We probe the available stack limit in the Makefile using rlimit, then use that to set the size of the stack when we clone() extra threads. But the rlimit at compile time need not be the same as the rlimit at runtime, so that's not particularly sensible. Ideally, we'd set the stack size based on an estimate of the actual maximum stack usage of all our clone()ed functions. We don't have that at the moment, but to keep things simple just set it to 1MiB - that's what the current probe will set things to on my default configuration Fedora 40, so it's likely to be fine in most cases. Signed-off-by: David Gibson Signed-off-by: Stefano Brivio --- Makefile | 6 ------ util.h | 2 +- 2 files changed, 1 insertion(+), 7 deletions(-) diff --git a/Makefile b/Makefile index 2a8540a..56bf2e8 100644 --- a/Makefile +++ b/Makefile @@ -15,11 +15,6 @@ VERSION ?= $(shell git describe --tags HEAD 2>/dev/null || echo "unknown\ versio # the IPv6 socket API? (Linux does) DUAL_STACK_SOCKETS := 1 -RLIMIT_STACK_VAL := $(shell /bin/sh -c 'ulimit -s') -ifeq ($(RLIMIT_STACK_VAL),unlimited) -RLIMIT_STACK_VAL := 1024 -endif - TARGET ?= $(shell $(CC) -dumpmachine) # Get 'uname -m'-like architecture description for target TARGET_ARCH := $(shell echo $(TARGET) | cut -f1 -d- | tr [A-Z] [a-z]) @@ -36,7 +31,6 @@ FLAGS := -Wall -Wextra -Wno-format-zero-length FLAGS += -pedantic -std=c11 -D_XOPEN_SOURCE=700 -D_GNU_SOURCE FLAGS += $(FORTIFY_FLAG) -O2 -pie -fPIE FLAGS += -DPAGE_SIZE=$(shell getconf PAGE_SIZE) -FLAGS += -DRLIMIT_STACK_VAL=$(RLIMIT_STACK_VAL) FLAGS += -DVERSION=\"$(VERSION)\" FLAGS += -DDUAL_STACK_SOCKETS=$(DUAL_STACK_SOCKETS) diff --git a/util.h b/util.h index 3fc64cf..c341236 100644 --- a/util.h +++ b/util.h @@ -132,7 +132,7 @@ static inline uint32_t ntohl_unaligned(const void *p) return ntohl(val); } -#define NS_FN_STACK_SIZE (RLIMIT_STACK_VAL * 1024 / 8) +#define NS_FN_STACK_SIZE (1024 * 1024) /* 1MiB */ int do_clone(int (*fn)(void *), char *stack_area, size_t stack_size, int flags, void *arg); #define NS_CALL(fn, arg) \