From: Yuntao Liu <liuyuntao12@huawei.com> hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/release-management/issues/ID5CMS -------------------------------- Intruduce xcall2.0 redis async prefetch kernel module. Signed-off-by: Yuntao Liu <liuyuntao12@huawei.com> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> --- drivers/staging/xcall/Makefile | 2 +- drivers/staging/xcall/prefetch.c | 267 +++++++++++++++++++++++++++++++ 2 files changed, 268 insertions(+), 1 deletion(-) create mode 100644 drivers/staging/xcall/prefetch.c diff --git a/drivers/staging/xcall/Makefile b/drivers/staging/xcall/Makefile index 668ac4f3b471..d8c6137e2945 100644 --- a/drivers/staging/xcall/Makefile +++ b/drivers/staging/xcall/Makefile @@ -1 +1 @@ -obj-$(CONFIG_DYNAMIC_XCALL_TESTCASE) += dynamic_xcall_test.o +obj-$(CONFIG_DYNAMIC_XCALL_TESTCASE) += dynamic_xcall_test.o prefetch.o diff --git a/drivers/staging/xcall/prefetch.c b/drivers/staging/xcall/prefetch.c new file mode 100644 index 000000000000..deaaeccd2455 --- /dev/null +++ b/drivers/staging/xcall/prefetch.c @@ -0,0 +1,267 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * A simple dummy xcall for syscall testing + * + * The data struct and functions marked as MANDATORY have to + * be includes in all of kernel xcall modules. + * + * Copyright (C) 2025 Huawei Limited. + */ + +#define pr_fmt(fmt) "dummy_xcall: " fmt + +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/hash.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/proc_fs.h> +#include <linux/socket.h> +#include <linux/xcall.h> +#include <net/sock.h> +#include <net/tcp_states.h> + +#include <asm/xcall.h> + +#define MAX_FD 100 + +static unsigned long xcall_cache_hit; +static unsigned long xcall_cache_miss; + +struct proc_dir_entry *xcall_proc_dir; + +enum cache_state { + XCALL_CACHE_NONE = 0, + XCALL_CACHE_PREFETCH, + XCALL_CACHE_READY, + XCALL_CACHE_CANCEL +}; + +struct prefetch_item { + int fd; + int cpu; + int pos; + int len; + atomic_t state; + struct file *file; + struct work_struct work; + char cache[PAGE_SIZE]; +}; + +static struct epoll_event events[MAX_FD] = {0}; + +static struct prefetch_item prefetch_items[MAX_FD] = {0}; +static struct workqueue_struct *rc_work; + +static inline bool transition_state(struct prefetch_item *pfi, + enum cache_state old, enum cache_state new) +{ + return atomic_cmpxchg(&pfi->state, old, new) == old; +} + +static void prefetch_work_fn(struct work_struct *work) +{ + struct prefetch_item *pfi = container_of(work, struct prefetch_item, work); + + if (!transition_state(pfi, XCALL_CACHE_NONE, XCALL_CACHE_PREFETCH)) + return; + + pfi->pos = 0; + pfi->len = kernel_read(pfi->file, pfi->cache, PAGE_SIZE, &pfi->file->f_pos); + + transition_state(pfi, XCALL_CACHE_PREFETCH, XCALL_CACHE_READY); +} + +static long __do_sys_epoll_pwait(struct pt_regs *regs) +{ + struct prefetch_item *pfi; + int i, fd, err; + long ret; + + ret = default_sys_call_table()[__NR_epoll_pwait](regs); + if (!ret) + return 0; + + err = copy_from_user(events, (void __user *)regs->regs[1], + ret * sizeof(struct epoll_event)); + if (err) + return -EFAULT; + + for (i = 0; i < ret; i++) { + fd = events[i].data; + if (events[i].events & EPOLLIN) { + pfi = &prefetch_items[fd]; + if (!pfi->file) + pfi->file = fget(fd); + + queue_work_on(250 + (fd % 4), rc_work, &pfi->work); + } + } + + return ret; +} + +static long __do_sys_read(struct pt_regs *regs) +{ + int fd = regs->regs[0]; + struct prefetch_item *pfi = &prefetch_items[fd]; + void *user_buf = (void *)regs->regs[1]; + int count = regs->regs[2]; + int copy_len; + long ret; + + if (!pfi->file) + goto not_epoll_fd; + + while (!transition_state(pfi, XCALL_CACHE_READY, XCALL_CACHE_CANCEL)) { + if (transition_state(pfi, XCALL_CACHE_NONE, XCALL_CACHE_CANCEL)) + goto slow_read; + } + + xcall_cache_hit++; + copy_len = pfi->len; + + if (copy_len == 0) { + transition_state(pfi, XCALL_CACHE_CANCEL, XCALL_CACHE_NONE); + return 0; + } + + copy_len = (copy_len >= count) ? count : copy_len; + copy_len -= copy_to_user(user_buf, (void *)(pfi->cache + pfi->pos), copy_len); + pfi->len -= copy_len; + pfi->pos += copy_len; + + if (pfi->len == 0) + transition_state(pfi, XCALL_CACHE_CANCEL, XCALL_CACHE_NONE); + else + transition_state(pfi, XCALL_CACHE_CANCEL, XCALL_CACHE_READY); + return copy_len; + +slow_read: + xcall_cache_miss++; + pfi->len = 0; + pfi->pos = 0; + cancel_work_sync(&pfi->work); + transition_state(pfi, XCALL_CACHE_CANCEL, XCALL_CACHE_NONE); +not_epoll_fd: + ret = default_sys_call_table()[__NR_read](regs); + return ret; +} + +static long __do_sys_close(struct pt_regs *regs) +{ + struct prefetch_item *pfi; + int fd = regs->regs[0]; + long ret; + + pfi = &prefetch_items[fd]; + if (pfi && pfi->file) { + fput(pfi->file); + pfi->file = NULL; + } + + ret = default_sys_call_table()[__NR_close](regs); + return ret; +} + +/* MANDATORY */ +static struct xcall_prog xcall_prefetch_prog = { + .name = "xcall_prefetch", + .owner = THIS_MODULE, + .objs = { + { + .scno = (unsigned long)__NR_epoll_pwait, + .func = (unsigned long)__do_sys_epoll_pwait, + }, + { + .scno = (unsigned long)__NR_read, + .func = (unsigned long)__do_sys_read, + }, + { + .scno = (unsigned long)__NR_close, + .func = (unsigned long)__do_sys_close, + }, + {} + } +}; + +static ssize_t xcall_prefetch_reset(struct file *file, const char __user *buf, + size_t count, loff_t *pos) +{ + xcall_cache_hit = 0; + xcall_cache_miss = 0; + + return count; +} + +static int xcall_prefetch_show(struct seq_file *m, void *v) +{ + u64 percent; + + percent = DIV_ROUND_CLOSEST(xcall_cache_hit * 100ULL, xcall_cache_hit + xcall_cache_miss); + seq_printf(m, "epoll cache_{hit,miss}: %lu,%lu, hit ratio: %llu%%\n", + xcall_cache_hit, xcall_cache_miss, percent); + return 0; +} + +static int xcall_prefetch_open(struct inode *inode, struct file *file) +{ + return single_open(file, xcall_prefetch_show, NULL); +} + +static const struct proc_ops xcall_prefetch_fops = { + .proc_open = xcall_prefetch_open, + .proc_read = seq_read, + .proc_write = xcall_prefetch_reset, + .proc_lseek = seq_lseek, + .proc_release = single_release +}; + +static int __init init_xcall_prefetch_procfs(void) +{ + struct proc_dir_entry *prefetch_dir; + + xcall_proc_dir = proc_mkdir("xcall_stat", NULL); + if (!xcall_proc_dir) + return -ENOMEM; + prefetch_dir = proc_create("prefetch", 0640, xcall_proc_dir, &xcall_prefetch_fops); + if (!prefetch_dir) + goto rm_xcall_proc_dir; + + return 0; + +rm_xcall_proc_dir: + proc_remove(xcall_proc_dir); + return -ENOMEM; +} + +/* MANDATORY */ +static int __init dummy_xcall_init(void) +{ + int i; + + rc_work = alloc_workqueue("eventpoll_rc", 0, 0); + if (!rc_work) + pr_warn("alloc eventpoll_rc workqueue failed.\n"); + + for (i = 0; i < MAX_FD; i++) + INIT_WORK(&prefetch_items[i].work, prefetch_work_fn); + + init_xcall_prefetch_procfs(); + + INIT_LIST_HEAD(&xcall_prefetch_prog.list); + return xcall_prog_register(&xcall_prefetch_prog); +} + +/* MANDATORY */ +static void __exit dummy_xcall_exit(void) +{ + proc_remove(xcall_proc_dir); + xcall_prog_unregister(&xcall_prefetch_prog); +} + +module_init(dummy_xcall_init); +module_exit(dummy_xcall_exit); +MODULE_AUTHOR("Liao Chang <liaochang1@huawei.com>"); +MODULE_DESCRIPTION("Dummy Xcall"); +MODULE_LICENSE("GPL"); -- 2.34.1