From 6affe1b71238df7bbbca6e2059e5494d91e68d2d Mon Sep 17 00:00:00 2001 From: Mateusz Guzik Date: Fri, 29 Jan 2021 00:33:46 +0100 Subject: select: employ fget_only_user Since most select users are single-threaded this avoid a lot of work in the common case. For example select of 16 fds (ops/s): before: 2114536 after: 2991010 --- sys/kern/sys_generic.c | 35 ++++++++++++++++++++++------------- 1 file changed, 22 insertions(+), 13 deletions(-) diff --git a/sys/kern/sys_generic.c b/sys/kern/sys_generic.c index a055f4a9b597..dc2cd56f5077 100644 --- a/sys/kern/sys_generic.c +++ b/sys/kern/sys_generic.c @@ -1304,13 +1304,6 @@ selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events) return (n); } -static __inline int -getselfd_cap(struct filedesc *fdp, int fd, struct file **fpp) -{ - - return (fget_unlocked(fdp, fd, &cap_event_rights, fpp)); -} - /* * Traverse the list of fds attached to this thread's seltd and check for * completion. @@ -1327,10 +1320,12 @@ selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits) fd_mask bit; int fd, ev, n, idx; int error; + bool only_user; fdp = td->td_proc->p_fd; stp = td->td_sel; n = 0; + only_user = FILEDESC_IS_ONLY_USER(fdp); STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { fd = (int)(uintptr_t)sfp->sf_cookie; si = sfp->sf_si; @@ -1338,13 +1333,19 @@ selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits) /* If the selinfo wasn't cleared the event didn't fire. */ if (si != NULL) continue; - error = getselfd_cap(fdp, fd, &fp); - if (error) + if (only_user) + error = fget_only_user(fdp, fd, &cap_event_rights, &fp); + else + error = fget_unlocked(fdp, fd, &cap_event_rights, &fp); + if (__predict_false(error != 0)) return (error); idx = fd / NFDBITS; bit = (fd_mask)1 << (fd % NFDBITS); ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td); - fdrop(fp, td); + if (only_user) + fput_only_user(fdp, fp); + else + fdrop(fp, td); if (ev != 0) n += selsetbits(ibits, obits, idx, bit, ev); } @@ -1366,9 +1367,11 @@ selscan(struct thread *td, fd_mask **ibits, fd_mask **obits, int nfd) int ev, flags, end, fd; int n, idx; int error; + bool only_user; fdp = td->td_proc->p_fd; n = 0; + only_user = FILEDESC_IS_ONLY_USER(fdp); for (idx = 0, fd = 0; fd < nfd; idx++) { end = imin(fd + NFDBITS, nfd); for (bit = 1; fd < end; bit <<= 1, fd++) { @@ -1376,12 +1379,18 @@ selscan(struct thread *td, fd_mask **ibits, fd_mask **obits, int nfd) flags = selflags(ibits, idx, bit); if (flags == 0) continue; - error = getselfd_cap(fdp, fd, &fp); - if (error) + if (only_user) + error = fget_only_user(fdp, fd, &cap_event_rights, &fp); + else + error = fget_unlocked(fdp, fd, &cap_event_rights, &fp); + if (__predict_false(error != 0)) return (error); selfdalloc(td, (void *)(uintptr_t)fd); ev = fo_poll(fp, flags, td->td_ucred, td); - fdrop(fp, td); + if (only_user) + fput_only_user(fdp, fp); + else + fdrop(fp, td); if (ev != 0) n += selsetbits(ibits, obits, idx, bit, ev); } -- cgit v1.2.3