Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 22 May 2016 12:35:50 +0000 (UTC)
From:      Dmitry Chagin <dchagin@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r300413 - head/sys/compat/linux
Message-ID:  <201605221235.u4MCZolo073115@repo.freebsd.org>

next in thread | raw e-mail | index | archive | help
Author: dchagin
Date: Sun May 22 12:35:50 2016
New Revision: 300413
URL: https://svnweb.freebsd.org/changeset/base/300413

Log:
  Due to lack the priority propagation feature replace sx by mutex. WIth this
  commit NPTL tests are ends in 1 minute faster.
  
  MFC after:	1 week

Modified:
  head/sys/compat/linux/linux_futex.c

Modified: head/sys/compat/linux/linux_futex.c
==============================================================================
--- head/sys/compat/linux/linux_futex.c	Sun May 22 12:28:55 2016	(r300412)
+++ head/sys/compat/linux/linux_futex.c	Sun May 22 12:35:50 2016	(r300413)
@@ -54,9 +54,10 @@ __KERNEL_RCSID(1, "$NetBSD: linux_futex.
 #include <sys/queue.h>
 #include <sys/sched.h>
 #include <sys/sdt.h>
-#include <sys/sx.h>
 #include <sys/umtx.h>
 
+#include <vm/vm_extern.h>
+
 #ifdef COMPAT_LINUX32
 #include <machine/../linux32/linux.h>
 #include <machine/../linux32/linux32_proto.h>
@@ -196,7 +197,7 @@ struct waiting_proc {
 };
 
 struct futex {
-	struct sx	f_lck;
+	struct mtx	f_lck;
 	uint32_t	*f_uaddr;	/* user-supplied value, for debug */
 	struct umtx_key	f_key;
 	uint32_t	f_refcount;
@@ -207,20 +208,22 @@ struct futex {
 
 struct futex_list futex_list;
 
-#define FUTEX_LOCK(f)		sx_xlock(&(f)->f_lck)
-#define FUTEX_UNLOCK(f)		sx_xunlock(&(f)->f_lck)
+#define FUTEX_LOCK(f)		mtx_lock(&(f)->f_lck)
+#define FUTEX_LOCKED(f)		mtx_owned(&(f)->f_lck)
+#define FUTEX_UNLOCK(f)		mtx_unlock(&(f)->f_lck)
 #define FUTEX_INIT(f)		do { \
-				    sx_init_flags(&(f)->f_lck, "ftlk", \
-					SX_DUPOK); \
+				    mtx_init(&(f)->f_lck, "ftlk", NULL, \
+					MTX_DUPOK); \
 				    LIN_SDT_PROBE1(futex, futex, create, \
 					&(f)->f_lck); \
 				} while (0)
 #define FUTEX_DESTROY(f)	do { \
 				    LIN_SDT_PROBE1(futex, futex, destroy, \
 					&(f)->f_lck); \
-				    sx_destroy(&(f)->f_lck); \
+				    mtx_destroy(&(f)->f_lck); \
 				} while (0)
-#define FUTEX_ASSERT_LOCKED(f)	sx_assert(&(f)->f_lck, SA_XLOCKED)
+#define FUTEX_ASSERT_LOCKED(f)	mtx_assert(&(f)->f_lck, MA_OWNED)
+#define FUTEX_ASSERT_UNLOCKED(f) mtx_assert(&(f)->f_lck, MA_NOTOWNED)
 
 struct mtx futex_mtx;			/* protects the futex list */
 #define FUTEXES_LOCK		do { \
@@ -239,6 +242,7 @@ struct mtx futex_mtx;			/* protects the 
 #define FUTEX_DONTCREATE	0x2	/* don't create futex if not exists */
 #define FUTEX_DONTEXISTS	0x4	/* return EINVAL if futex exists */
 #define	FUTEX_SHARED		0x8	/* shared futex */
+#define	FUTEX_DONTLOCK		0x10	/* don't lock futex */
 
 /* wp_flags */
 #define FUTEX_WP_REQUEUED	0x1	/* wp requeued - wp moved from wp_list
@@ -258,6 +262,8 @@ static int futex_wake(struct futex *, in
 static int futex_requeue(struct futex *, int, struct futex *, int);
 static int futex_wait(struct futex *, struct waiting_proc *, int,
     uint32_t);
+static void futex_lock(struct futex *);
+static void futex_unlock(struct futex *);
 static int futex_atomic_op(struct thread *, int, uint32_t *);
 static int handle_futex_death(struct linux_emuldata *, uint32_t *,
     unsigned int);
@@ -277,7 +283,6 @@ futex_put(struct futex *f, struct waitin
 {
 	LIN_SDT_PROBE2(futex, futex_put, entry, f, wp);
 
-	FUTEX_ASSERT_LOCKED(f);
 	if (wp != NULL) {
 		if ((wp->wp_flags & FUTEX_WP_REMOVED) == 0)
 			TAILQ_REMOVE(&f->f_waiting_proc, wp, wp_list);
@@ -288,7 +293,8 @@ futex_put(struct futex *f, struct waitin
 	if (--f->f_refcount == 0) {
 		LIST_REMOVE(f, f_list);
 		FUTEXES_UNLOCK;
-		FUTEX_UNLOCK(f);
+		if (FUTEX_LOCKED(f))
+			futex_unlock(f);
 
 		LIN_SDT_PROBE3(futex, futex_put, destroy, f->f_uaddr,
 		    f->f_refcount, f->f_key.shared);
@@ -307,7 +313,8 @@ futex_put(struct futex *f, struct waitin
 	LINUX_CTR3(sys_futex, "futex_put uaddr %p ref %d shared %d",
 	    f->f_uaddr, f->f_refcount, f->f_key.shared);
 	FUTEXES_UNLOCK;
-	FUTEX_UNLOCK(f);
+	if (FUTEX_LOCKED(f))
+		futex_unlock(f);
 
 	LIN_SDT_PROBE0(futex, futex_put, return);
 }
@@ -335,7 +342,8 @@ retry:
 	LIST_FOREACH(f, &futex_list, f_list) {
 		if (umtx_key_match(&f->f_key, &key)) {
 			if (tmpf != NULL) {
-				FUTEX_UNLOCK(tmpf);
+				if (FUTEX_LOCKED(tmpf))
+					futex_unlock(tmpf);
 				FUTEX_DESTROY(tmpf);
 				free(tmpf, M_FUTEX);
 			}
@@ -356,7 +364,8 @@ retry:
 			FUTEXES_UNLOCK;
 			umtx_key_release(&key);
 
-			FUTEX_LOCK(f);
+			if ((flags & FUTEX_DONTLOCK) == 0)
+				futex_lock(f);
 			*newf = f;
 			LIN_SDT_PROBE3(futex, futex_get0, shared, uaddr,
 			    f->f_refcount, f->f_key.shared);
@@ -392,7 +401,8 @@ retry:
 		 * Lock the new futex before an insert into the futex_list
 		 * to prevent futex usage by other.
 		 */
-		FUTEX_LOCK(tmpf);
+		if ((flags & FUTEX_DONTLOCK) == 0)
+			futex_lock(tmpf);
 		goto retry;
 	}
 
@@ -440,6 +450,26 @@ futex_get(uint32_t *uaddr, struct waitin
 	return (error);
 }
 
+static inline void
+futex_lock(struct futex *f)
+{
+
+	LINUX_CTR3(sys_futex, "futex_lock uaddr %p ref %d shared %d",
+	    f->f_uaddr, f->f_refcount, f->f_key.shared);
+	FUTEX_ASSERT_UNLOCKED(f);
+	FUTEX_LOCK(f);
+}
+
+static inline void
+futex_unlock(struct futex *f)
+{
+
+	LINUX_CTR3(sys_futex, "futex_unlock uaddr %p ref %d shared %d",
+	    f->f_uaddr, f->f_refcount, f->f_key.shared);
+	FUTEX_ASSERT_LOCKED(f);
+	FUTEX_UNLOCK(f);
+}
+
 static int
 futex_sleep(struct futex *f, struct waiting_proc *wp, int timeout)
 {
@@ -449,7 +479,7 @@ futex_sleep(struct futex *f, struct wait
 	LIN_SDT_PROBE3(futex, futex_sleep, entry, f, wp, timeout);
 	LINUX_CTR4(sys_futex, "futex_sleep enter uaddr %p wp %p timo %d ref %d",
 	    f->f_uaddr, wp, timeout, f->f_refcount);
-	error = sx_sleep(wp, &f->f_lck, PCATCH, "futex", timeout);
+	error = mtx_sleep(wp, &f->f_lck, PCATCH, "futex", timeout);
 	if (wp->wp_flags & FUTEX_WP_REQUEUED) {
 		KASSERT(f != wp->wp_futex, ("futex != wp_futex"));
 
@@ -465,7 +495,7 @@ futex_sleep(struct futex *f, struct wait
 		    wp->wp_futex->f_refcount);
 		futex_put(f, NULL);
 		f = wp->wp_futex;
-		FUTEX_LOCK(f);
+		futex_lock(f);
 	} else {
 		if (error) {
 			LIN_SDT_PROBE3(futex, futex_sleep, sleep_error, error,
@@ -676,7 +706,7 @@ linux_sys_futex(struct thread *td, struc
 	struct timespec timeout;
 	struct timeval utv, ctv;
 	int timeout_hz;
-	int error;
+	int error, save;
 	uint32_t flags, val;
 
 	LIN_SDT_PROBE2(futex, linux_sys_futex, entry, td, args);
@@ -749,6 +779,7 @@ linux_sys_futex(struct thread *td, struc
 		} else
 			timeout_hz = 0;
 
+retry0:
 		error = futex_get(args->uaddr, &wp, &f,
 		    flags | FUTEX_CREATE_WP);
 		if (error) {
@@ -756,14 +787,16 @@ linux_sys_futex(struct thread *td, struc
 			return (error);
 		}
 
-		error = copyin(args->uaddr, &val, sizeof(val));
+		error = copyin_nofault(args->uaddr, &val, sizeof(val));
 		if (error) {
+			futex_put(f, wp);
+			error = copyin(args->uaddr, &val, sizeof(val));
+			if (error == 0)
+				goto retry0;
 			LIN_SDT_PROBE1(futex, linux_sys_futex, copyin_error,
 			    error);
 			LINUX_CTR1(sys_futex, "WAIT copyin failed %d",
 			    error);
-			futex_put(f, wp);
-
 			LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
 			return (error);
 		}
@@ -831,7 +864,8 @@ linux_sys_futex(struct thread *td, struc
 			return (EINVAL);
 		}
 
-		error = futex_get(args->uaddr, NULL, &f, flags);
+retry1:
+		error = futex_get(args->uaddr, NULL, &f, flags | FUTEX_DONTLOCK);
 		if (error) {
 			LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
 			return (error);
@@ -845,22 +879,26 @@ linux_sys_futex(struct thread *td, struc
 		 * returned by FUTEX_CMP_REQUEUE.
 		 */
 		error = futex_get(args->uaddr2, NULL, &f2,
-		    flags | FUTEX_DONTEXISTS);
+		    flags | FUTEX_DONTEXISTS | FUTEX_DONTLOCK);
 		if (error) {
 			futex_put(f, NULL);
 
 			LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
 			return (error);
 		}
-		error = copyin(args->uaddr, &val, sizeof(val));
+		futex_lock(f);
+		futex_lock(f2);
+		error = copyin_nofault(args->uaddr, &val, sizeof(val));
 		if (error) {
+			futex_put(f2, NULL);
+			futex_put(f, NULL);
+			error = copyin(args->uaddr, &val, sizeof(val));
+			if (error == 0)
+				goto retry1;
 			LIN_SDT_PROBE1(futex, linux_sys_futex, copyin_error,
 			    error);
 			LINUX_CTR1(sys_futex, "CMP_REQUEUE copyin failed %d",
 			    error);
-			futex_put(f2, NULL);
-			futex_put(f, NULL);
-
 			LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
 			return (error);
 		}
@@ -890,50 +928,45 @@ linux_sys_futex(struct thread *td, struc
 		    args->uaddr, args->val, args->uaddr2, args->val3,
 		    args->timeout);
 
-		error = futex_get(args->uaddr, NULL, &f, flags);
+retry2:
+		error = futex_get(args->uaddr, NULL, &f, flags | FUTEX_DONTLOCK);
 		if (error) {
 			LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
 			return (error);
 		}
 
 		if (args->uaddr != args->uaddr2)
-			error = futex_get(args->uaddr2, NULL, &f2, flags);
+			error = futex_get(args->uaddr2, NULL, &f2,
+			    flags | FUTEX_DONTLOCK);
 		if (error) {
 			futex_put(f, NULL);
 
 			LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
 			return (error);
 		}
+		futex_lock(f);
+		futex_lock(f2);
 
 		/*
 		 * This function returns positive number as results and
 		 * negative as errors
 		 */
+		save = vm_fault_disable_pagefaults();
 		op_ret = futex_atomic_op(td, args->val3, args->uaddr2);
+		vm_fault_enable_pagefaults(save);
 
 		LINUX_CTR2(sys_futex, "WAKE_OP atomic_op uaddr %p ret 0x%x",
 		    args->uaddr, op_ret);
 
 		if (op_ret < 0) {
-			/* XXX: We don't handle the EFAULT yet. */
-			if (op_ret != -EFAULT) {
-				if (f2 != NULL)
-					futex_put(f2, NULL);
-				futex_put(f, NULL);
-
-				LIN_SDT_PROBE1(futex, linux_sys_futex, return,
-				    -op_ret);
-				return (-op_ret);
-			} else {
-				LIN_SDT_PROBE0(futex, linux_sys_futex,
-				    unhandled_efault);
-			}
 			if (f2 != NULL)
 				futex_put(f2, NULL);
 			futex_put(f, NULL);
-
-			LIN_SDT_PROBE1(futex, linux_sys_futex, return, EFAULT);
-			return (EFAULT);
+			error = copyin(args->uaddr2, &val, sizeof(val));
+			if (error == 0)
+				goto retry2;
+			LIN_SDT_PROBE1(futex, linux_sys_futex, return, error);
+			return (error);
 		}
 
 		ret = futex_wake(f, args->val, args->val3);



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201605221235.u4MCZolo073115>