diff --git a/src/unix/linux.c b/src/unix/linux.c index 0fa565b7..763f5dd5 100644 --- a/src/unix/linux.c +++ b/src/unix/linux.c @@ -455,7 +455,7 @@ int uv__io_uring_register(int fd, unsigned opcode, void* arg, unsigned nargs) { } -static int uv__use_io_uring(void) { +static int uv__use_io_uring(uint32_t flags) { #if defined(__ANDROID_API__) return 0; /* Possibly available but blocked by seccomp. */ #elif defined(__arm__) && __SIZEOF_POINTER__ == 4 @@ -470,25 +470,27 @@ static int uv__use_io_uring(void) { char* val; int use; +#if defined(__hppa__) + /* io_uring first supported on parisc in 6.1, functional in .51 + * https://lore.kernel.org/all/cb912694-b1fe-dbb0-4d8c-d608f3526905@gmx.de/ + */ + if (uv__kernel_version() < /*6.1.51*/0x060133) + return 0; +#endif + + /* SQPOLL is all kinds of buggy but epoll batching should work fine. */ + if (0 == (flags & UV__IORING_SETUP_SQPOLL)) + return 1; + + /* Older kernels have a bug where the sqpoll thread uses 100% CPU. */ + if (uv__kernel_version() < /*5.10.186*/0x050ABA) + return 0; + use = atomic_load_explicit(&use_io_uring, memory_order_relaxed); if (use == 0) { - use = uv__kernel_version() >= -#if defined(__hppa__) - /* io_uring first supported on parisc in 6.1, functional in .51 */ - /* https://lore.kernel.org/all/cb912694-b1fe-dbb0-4d8c-d608f3526905@gmx.de/ */ - /* 6.1.51 */ 0x060133 -#else - /* Older kernels have a bug where the sqpoll thread uses 100% CPU. */ - /* 5.10.186 */ 0x050ABA -#endif - ? 1 : -1; - - /* But users can still enable it if they so desire. */ val = getenv("UV_USE_IO_URING"); - if (val != NULL) - use = atoi(val) ? 1 : -1; - + use = val != NULL && atoi(val) > 0 ? 1 : -1; atomic_store_explicit(&use_io_uring, use, memory_order_relaxed); } @@ -518,7 +520,7 @@ static void uv__iou_init(int epollfd, sq = MAP_FAILED; sqe = MAP_FAILED; - if (!uv__use_io_uring()) + if (!uv__use_io_uring(flags)) return; kernel_version = uv__kernel_version(); @@ -766,14 +768,13 @@ static struct uv__io_uring_sqe* uv__iou_get_sqe(struct uv__iou* iou, */ if (iou->ringfd == -2) { /* By default, the SQPOLL is not created. Enable only if the loop is - * configured with UV_LOOP_USE_IO_URING_SQPOLL. + * configured with UV_LOOP_USE_IO_URING_SQPOLL and the UV_USE_IO_URING + * environment variable is unset or a positive number. */ - if ((loop->flags & UV_LOOP_ENABLE_IO_URING_SQPOLL) == 0) { - iou->ringfd = -1; - return NULL; - } + if (loop->flags & UV_LOOP_ENABLE_IO_URING_SQPOLL) + if (uv__use_io_uring(UV__IORING_SETUP_SQPOLL)) + uv__iou_init(loop->backend_fd, iou, 64, UV__IORING_SETUP_SQPOLL); - uv__iou_init(loop->backend_fd, iou, 64, UV__IORING_SETUP_SQPOLL); if (iou->ringfd == -2) iou->ringfd = -1; /* "failed" */ }