Hi, Mathieu, On Thu, Oct 16, 2025 at 09:32:04AM -0600, Mathieu Poirier wrote: > I have applied this set. > > Thanks, > Mathieu
It seems that it is v4 being applied? [1] The only difference between v4 and v5 is commit message, though. [1] https://git.kernel.org/pub/scm/linux/kernel/git/remoteproc/linux.git/commit/?h=rpmsg-next&id=00af63201cbb7903e5deb2a9fdebd97f979492e5 > > On Wed, Oct 15, 2025 at 11:17:15PM +0800, Dawei Li wrote: > > Hi, > > > > This is V5 of series which introduce new uAPI(RPMSG_CREATE_EPT_FD_IOCTL) > > for rpmsg subsystem. > > > > Current uAPI implementation for rpmsg ctrl & char device manipulation is > > abstracted in procedures below: > > - fd = open("/dev/rpmsg_ctrlX") > > - ioctl(fd, RPMSG_CREATE_EPT_IOCTL, &info); /dev/rpmsgY devnode is > > generated. > > - fd_ep = open("/dev/rpmsgY", O_RDWR) > > - operations on fd_ep(write, read, poll ioctl) > > - ioctl(fd_ep, RPMSG_DESTROY_EPT_IOCTL) > > - close(fd_ep) > > - close(fd) > > > > This /dev/rpmsgY abstraction is less favorable for: > > - Performance issue: It's time consuming for some operations are > > involved: > > - Device node creation. > > Depends on specific config, especially CONFIG_DEVTMPFS, the overall > > overhead is based on coordination between DEVTMPFS and userspace > > tools such as udev and mdev. > > - Extra kernel-userspace switch cost. > > - Other major costs brought by heavy-weight logic like device_add(). > > > > - /dev/rpmsgY node can be opened only once. It doesn't make much sense > > that a dynamically created device node can be opened only once. > > > > - For some container application such as docker, a client can't access > > host's dev unless specified explicitly. But in case of /dev/rpmsgY, which > > is generated dynamically and whose existence is unknown for clients in > > advance, this uAPI based on device node doesn't fit well. > > > > An anonymous inode based approach is introduced to address the issues > > above. Rather than generating device node and opening it, rpmsg code just > > creates an anonymous inode representing eptdev and return the fd to > > userspace. > > > > Performance demo > > > > A simple C application is tested to verify performance of new uAPI. > > Please be noted that all '#' in code are preceded with space to suppress > > checkpatch complaints. > > > > $ cat test.c > > > > #include <linux/rpmsg.h> > > > > #include <sys/types.h> > > #include <sys/stat.h> > > #include <sys/ioctl.h> > > #include <fcntl.h> > > #include <string.h> > > #include <stdio.h> > > #include <unistd.h> > > #include <stdlib.h> > > #include <errno.h> > > #include <sys/time.h> > > > > #define N (1 << 20) > > > > int main(int argc, char *argv[]) > > { > > int ret, fd, ep_fd, loop; > > struct rpmsg_endpoint_info info; > > struct rpmsg_endpoint_fd_info fd_info; > > struct timeval start, end; > > int i = 0; > > double t1, t2; > > > > fd = -1; > > ep_fd = -1; > > loop = N; > > > > if (argc == 1) { > > loop = N; > > } else if (argc > 1) { > > loop = atoi(argv[1]); > > } > > > > printf("loop[%d]\n", loop); > > > > strcpy(info.name, "epx"); > > info.src = -1; > > info.dst = -1; > > > > strcpy(fd_info.name, "epx"); > > fd_info.src = -1; > > fd_info.dst = -1; > > fd_info.fd = -1; > > > > while (fd < 0) { > > fd = open("/dev/rpmsg_ctrl0", O_RDWR); > > if (fd < 0) { > > printf("open rpmsg_ctrl0 failed, fd[%d]\n", fd); > > } > > } > > > > gettimeofday(&start, NULL); > > > > while (loop--) { > > ret = ioctl(fd, RPMSG_CREATE_EPT_IOCTL, &info); > > if (ret < 0) { > > printf("ioctl[RPMSG_CREATE_EPT_IOCTL] failed, > > ret[%d]\n", ret); > > } > > > > ep_fd = -1; > > i = 0; > > > > while (ep_fd < 0) { > > ep_fd = open("/dev/rpmsg0", O_RDWR); > > if (ep_fd < 0) { > > i++; > > printf("open rpmsg0 failed, epfd[%d]\n", ep_fd); > > } > > } > > > > ret = ioctl(ep_fd, RPMSG_DESTROY_EPT_IOCTL, &info); > > if (ret < 0) { > > printf("old RPMSG_DESTROY_EPT_IOCTL failed, ret[%d], > > errno[%d]\n", > > ret, errno); > > } > > > > close(ep_fd); > > } > > > > gettimeofday(&end, NULL); > > > > printf("time for old way: [%ld] us\n", > > 1000000 * (end.tv_sec - start.tv_sec) + end.tv_usec - > > start.tv_usec); > > t1 = 1000000 * (end.tv_sec - start.tv_sec) + end.tv_usec - > > start.tv_usec; > > > > if (argc == 1) { > > loop = N; > > } else if (argc > 1) { > > loop = atoi(argv[1]); > > } > > > > printf("loop[%d]\n", loop); > > > > gettimeofday(&start, NULL); > > > > while (loop--) { > > fd_info.fd = -1; > > fd_info.flags = O_RDWR | O_CLOEXEC | O_NONBLOCK; > > ret = ioctl(fd, RPMSG_CREATE_EPT_FD_IOCTL, &fd_info); > > if (ret < 0 || fd_info.fd < 0) { > > printf("ioctl[RPMSG_CREATE_EPT_FD_IOCTL] failed, > > ret[%d]\n", ret); > > } > > > > ret = ioctl(fd_info.fd, RPMSG_DESTROY_EPT_IOCTL, &info); > > if (ret < 0) { > > printf("new ioctl[RPMSG_DESTROY_EPT_IOCTL] failed, > > ret[%d]\n", ret); > > } > > > > close(fd_info.fd); > > } > > > > gettimeofday(&end, NULL); > > > > printf("time for new way: [%ld] us\n", > > 1000000 * (end.tv_sec - start.tv_sec) + end.tv_usec - start.tv_usec); > > t2 = 1000000 * (end.tv_sec - start.tv_sec) + end.tv_usec - > > start.tv_usec; > > > > printf("t1(old) / t2(new) = %f\n", t1 / t2); > > > > close(fd); > > } > > > > Performance benchmark > > > > - Legacy means benchmark based on old uAPI > > - New means benchmark based on new uAPI(the one this series introduce) > > - Time are in units of us(10^-6 s) > > > > Test loops Total time(legacy) Total time(new) legacy/new > > 1 1000 148362 1153 128.674761 > > 2 1000 145640 1121 129.919715 > > 3 1000 145303 1174 123.767462 > > 4 1000 150294 1142 131.605954 > > 5 1000 160877 1175 136.916596 > > 6 1000 154400 1134 136.155203 > > 7 1000 143252 1163 123.174549 > > 8 1000 148758 1161 128.129199 > > 9 1000 149044 1112 134.032374 > > 10 1000 146895 1192 123.234060 > > 11 10000 1428967 11627 122.900748 > > 12 10000 1367015 10557 129.488965 > > 13 10000 1371919 11663 117.630027 > > 14 10000 1358447 11080 122.603520 > > 15 10000 1375463 11245 122.317741 > > 16 10000 1364901 11153 122.379718 > > 17 10000 1352665 10735 126.005123 > > 18 10000 1400873 11341 123.522882 > > 19 10000 1391276 10892 127.733750 > > 20 10000 1394367 11110 125.505581 > > 21 100000 14069671 115569 121.742604 > > 22 100000 13663364 117074 116.707074 > > 23 100000 13735740 115638 118.782234 > > 24 100000 13714441 119362 114.897882 > > 25 100000 13904366 118282 117.552679 > > 26 100000 13870560 117717 117.829710 > > 27 100000 13713605 118312 115.910516 > > 28 100000 13872852 114347 121.322396 > > 29 100000 13777964 119072 115.711200 > > 30 100000 13725654 116296 118.023440 > > > > Changelog: > > > > Changes in v5: > > - Rebased on v6.18.rc1. > > - Fix checkpatch warning on commit msg on patch[1/3]. > > - Other minor commit msg tweaks. > > - Update performance testing results. > > - Link to v4: > > https://lore.kernel.org/all/[email protected]/ > > > > Changes in v4: > > - Build warning of copy_to_user (Dan). > > - ioctl() branches reorder (Beleswar). > > - Remove local variable fd and pass &ept_fd_info.fd to > > rpmsg_anonymous_eptdev_create(). > > - Link to v3: > > https://lore.kernel.org/all/[email protected]/ > > > > Changes in v3: > > - s/anon/anonymous (Mathieu) > > - API naming adjustment (Mathieu) > > - __rpmsg_chrdev_eptdev_alloc -> rpmsg_eptdev_alloc > > - __rpmsg_chrdev_eptdev_add -> rpmsg_eptdev_add > > - Add parameter 'flags' to uAPI so user can specify file flags > > explicitly on creating anonymous inode. > > - Link to v2: > > https://lore.kernel.org/all/[email protected]/ > > > > Changes in v2: > > - Fix compilation error for !CONFIG_RPMSG_CHAR config(Test robot). > > - Link to v1: > > https://lore.kernel.org/all/[email protected]/ > > > > Dawei Li (3): > > rpmsg: char: Reuse eptdev logic for anonymous device > > rpmsg: char: Implement eptdev based on anonymous inode > > rpmsg: ctrl: Introduce RPMSG_CREATE_EPT_FD_IOCTL uAPI > > > > drivers/rpmsg/rpmsg_char.c | 129 ++++++++++++++++++++++++++++++------- > > drivers/rpmsg/rpmsg_char.h | 23 +++++++ > > drivers/rpmsg/rpmsg_ctrl.c | 35 ++++++++-- > > include/uapi/linux/rpmsg.h | 27 +++++++- > > 4 files changed, 182 insertions(+), 32 deletions(-) > > > > --- > > > > Thanks, > > > > Dawei > > > > -- > > 2.25.1 > > Thanks, Dawei
