Attachment 221517 Details for Bug 252582 – drop_epoll_data.patch

[patch] drop_epoll_data.patch

epoll.patch (text/plain), 7.18 KB, created by Vladimir Kondratyev on 2021-01-13 00:53:40 UTC

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Creator: Vladimir Kondratyev

Created: 2021-01-13 00:53:40 UTC

Size: 7.18 KB

patch

obsolete

>commit cc394bbc816104d95a8baf300a947dc205de27f2
>Author: Vladimir Kondratyev <wulf@FreeBSD.org>
>Date:   Wed Dec 27 23:46:58 2017 +0300
>
>    epoll: Store user data variable in extended data member of kevent.
>    
>    This makes allocation of per process epoll array unnecessary.
>
>diff --git a/sys/compat/linux/linux_emul.c b/sys/compat/linux/linux_emul.c
>index 1dfbe239ccc..499bebe8926 100644
>--- a/sys/compat/linux/linux_emul.c
>+++ b/sys/compat/linux/linux_emul.c
>@@ -143,7 +143,6 @@ linux_proc_init(struct thread *td, struct thread *newtd, int flags)
> {
> 	struct linux_emuldata *em;
> 	struct linux_pemuldata *pem;
>-	struct epoll_emuldata *emd;
> 	struct proc *p;
> 
> 	if (newtd != NULL) {
>@@ -185,15 +184,9 @@ linux_proc_init(struct thread *td, struct thread *newtd, int flags)
> 		em->child_clear_tid = NULL;
> 		em->child_set_tid = NULL;
> 
>-		 /* epoll should be destroyed in a case of exec. */
> 		pem = pem_find(p);
> 		KASSERT(pem != NULL, ("proc_exit: proc emuldata not found.\n"));
> 		pem->persona = 0;
>-		if (pem->epoll != NULL) {
>-			emd = pem->epoll;
>-			pem->epoll = NULL;
>-			free(emd, M_EPOLL);
>-		}
> 	}
> 
> }
>@@ -202,7 +195,6 @@ void
> linux_on_exit(struct proc *p)
> {
> 	struct linux_pemuldata *pem;
>-	struct epoll_emuldata *emd;
> 	struct thread *td = curthread;
> 
> 	MPASS(SV_CURPROC_ABI() == SV_ABI_LINUX);
>@@ -217,12 +209,6 @@ linux_on_exit(struct proc *p)
> 
> 	p->p_emuldata = NULL;
> 
>-	if (pem->epoll != NULL) {
>-		emd = pem->epoll;
>-		pem->epoll = NULL;
>-		free(emd, M_EPOLL);
>-	}
>-
> 	sx_destroy(&pem->pem_sx);
> 	free(pem, M_LINUX);
> }
>@@ -267,7 +253,6 @@ int
> linux_common_execve(struct thread *td, struct image_args *eargs)
> {
> 	struct linux_pemuldata *pem;
>-	struct epoll_emuldata *emd;
> 	struct vmspace *oldvmspace;
> 	struct linux_emuldata *em;
> 	struct proc *p;
>@@ -299,12 +284,6 @@ linux_common_execve(struct thread *td, struct image_args *eargs)
> 		p->p_emuldata = NULL;
> 		PROC_UNLOCK(p);
> 
>-		if (pem->epoll != NULL) {
>-			emd = pem->epoll;
>-			pem->epoll = NULL;
>-			free(emd, M_EPOLL);
>-		}
>-
> 		free(em, M_TEMP);
> 		free(pem, M_LINUX);
> 	}
>diff --git a/sys/compat/linux/linux_emul.h b/sys/compat/linux/linux_emul.h
>index 1bbc69ad98b..de66a7a4c82 100644
>--- a/sys/compat/linux/linux_emul.h
>+++ b/sys/compat/linux/linux_emul.h
>@@ -68,7 +68,6 @@ int	linux_common_execve(struct thread *, struct image_args *);
> struct linux_pemuldata {
> 	uint32_t	flags;		/* process emuldata flags */
> 	struct sx	pem_sx;		/* lock for this struct */
>-	void		*epoll;		/* epoll data */
> 	uint32_t	persona;	/* process execution domain */
> 	uint32_t	ptrace_flags;	/* used by ptrace(2) */
> };
>diff --git a/sys/compat/linux/linux_event.c b/sys/compat/linux/linux_event.c
>index b4b4be1f7b4..a5b88749519 100644
>--- a/sys/compat/linux/linux_event.c
>+++ b/sys/compat/linux/linux_event.c
>@@ -71,25 +71,8 @@ __FBSDID("$FreeBSD$");
> #include <compat/linux/linux_timer.h>
> #include <compat/linux/linux_util.h>
> 
>-/*
>- * epoll defines 'struct epoll_event' with the field 'data' as 64 bits
>- * on all architectures. But on 32 bit architectures BSD 'struct kevent' only
>- * has 32 bit opaque pointer as 'udata' field. So we can't pass epoll supplied
>- * data verbatuim. Therefore we allocate 64-bit memory block to pass
>- * user supplied data for every file descriptor.
>- */
>-
> typedef uint64_t	epoll_udata_t;
> 
>-struct epoll_emuldata {
>-	uint32_t	fdc;		/* epoll udata max index */
>-	epoll_udata_t	udata[1];	/* epoll user data vector */
>-};
>-
>-#define	EPOLL_DEF_SZ		16
>-#define	EPOLL_SIZE(fdn)			\
>-	(sizeof(struct epoll_emuldata)+(fdn) * sizeof(epoll_udata_t))
>-
> struct epoll_event {
> 	uint32_t	events;
> 	epoll_udata_t	data;
>@@ -101,7 +84,6 @@ __attribute__((packed))
> 
> #define	LINUX_MAX_EVENTS	(INT_MAX / sizeof(struct epoll_event))
> 
>-static void	epoll_fd_install(struct thread *td, int fd, epoll_udata_t udata);
> static int	epoll_to_kevent(struct thread *td, int fd,
> 		    struct epoll_event *l_event, struct kevent *kevent,
> 		    int *nkevents);
>@@ -175,35 +157,6 @@ struct timerfd {
> static void	linux_timerfd_expire(void *);
> static void	linux_timerfd_curval(struct timerfd *, struct itimerspec *);
> 
>-static void
>-epoll_fd_install(struct thread *td, int fd, epoll_udata_t udata)
>-{
>-	struct linux_pemuldata *pem;
>-	struct epoll_emuldata *emd;
>-	struct proc *p;
>-
>-	p = td->td_proc;
>-
>-	pem = pem_find(p);
>-	KASSERT(pem != NULL, ("epoll proc emuldata not found.\n"));
>-
>-	LINUX_PEM_XLOCK(pem);
>-	if (pem->epoll == NULL) {
>-		emd = malloc(EPOLL_SIZE(fd), M_EPOLL, M_WAITOK);
>-		emd->fdc = fd;
>-		pem->epoll = emd;
>-	} else {
>-		emd = pem->epoll;
>-		if (fd > emd->fdc) {
>-			emd = realloc(emd, EPOLL_SIZE(fd), M_EPOLL, M_WAITOK);
>-			emd->fdc = fd;
>-			pem->epoll = emd;
>-		}
>-	}
>-	emd->udata[fd] = udata;
>-	LINUX_PEM_XUNLOCK(pem);
>-}
>-
> static int
> epoll_create_common(struct thread *td, int flags)
> {
>@@ -213,8 +166,6 @@ epoll_create_common(struct thread *td, int flags)
> 	if (error != 0)
> 		return (error);
> 
>-	epoll_fd_install(td, EPOLL_DEF_SZ, 0);
>-
> 	return (0);
> }
> 
>@@ -271,11 +222,15 @@ epoll_to_kevent(struct thread *td, int fd, struct epoll_event *l_event,
> 
> 	/* flags related to what event is registered */
> 	if ((levents & LINUX_EPOLL_EVRD) != 0) {
>-		EV_SET(kevent++, fd, EVFILT_READ, kev_flags, 0, 0, 0);
>+		EV_SET(kevent, fd, EVFILT_READ, kev_flags, 0, 0, 0);
>+		kevent->ext[0] = l_event->data;
>+		++kevent;
> 		++(*nkevents);
> 	}
> 	if ((levents & LINUX_EPOLL_EVWR) != 0) {
>-		EV_SET(kevent++, fd, EVFILT_WRITE, kev_flags, 0, 0, 0);
>+		EV_SET(kevent, fd, EVFILT_WRITE, kev_flags, 0, 0, 0);
>+		kevent->ext[0] = l_event->data;
>+		++kevent;
> 		++(*nkevents);
> 	}
> 	/* zero event mask is legal */
>@@ -289,7 +244,6 @@ epoll_to_kevent(struct thread *td, int fd, struct epoll_event *l_event,
> 
> 		pem = pem_find(p);
> 		KASSERT(pem != NULL, ("epoll proc emuldata not found.\n"));
>-		KASSERT(pem->epoll != NULL, ("epoll proc epolldata not found.\n"));
> 
> 		LINUX_PEM_XLOCK(pem);
> 		if ((pem->flags & LINUX_XUNSUP_EPOLL) == 0) {
>@@ -314,6 +268,8 @@ static void
> kevent_to_epoll(struct kevent *kevent, struct epoll_event *l_event)
> {
> 
>+	l_event->data = kevent->ext[0];
>+
> 	if ((kevent->flags & EV_ERROR) != 0) {
> 		l_event->events = LINUX_EPOLLERR;
> 		return;
>@@ -342,30 +298,15 @@ static int
> epoll_kev_copyout(void *arg, struct kevent *kevp, int count)
> {
> 	struct epoll_copyout_args *args;
>-	struct linux_pemuldata *pem;
>-	struct epoll_emuldata *emd;
> 	struct epoll_event *eep;
>-	int error, fd, i;
>+	int error, i;
> 
> 	args = (struct epoll_copyout_args*) arg;
> 	eep = malloc(sizeof(*eep) * count, M_EPOLL, M_WAITOK | M_ZERO);
> 
>-	pem = pem_find(args->p);
>-	KASSERT(pem != NULL, ("epoll proc emuldata not found.\n"));
>-	LINUX_PEM_SLOCK(pem);
>-	emd = pem->epoll;
>-	KASSERT(emd != NULL, ("epoll proc epolldata not found.\n"));
>-
>-	for (i = 0; i < count; i++) {
>+	for (i = 0; i < count; i++)
> 		kevent_to_epoll(&kevp[i], &eep[i]);
> 
>-		fd = kevp[i].ident;
>-		KASSERT(fd <= emd->fdc, ("epoll user data vector"
>-						    " is too small.\n"));
>-		eep[i].data = emd->udata[fd];
>-	}
>-	LINUX_PEM_SUNLOCK(pem);
>-
> 	error = copyout(eep, args->leventlist, count * sizeof(*eep));
> 	if (error == 0) {
> 		args->leventlist += count;
>@@ -472,8 +413,6 @@ linux_epoll_ctl(struct thread *td, struct linux_epoll_ctl_args *args)
> 		goto leave0;
> 	}
> 
>-	epoll_fd_install(td, args->fd, le.data);
>-
> 	error = kern_kevent_fp(td, epfp, nchanges, 0, &k_ops, NULL);
> 
> leave0:

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Attachments on bug 252582: 221464 | 221465 | 221517 | 221549