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Date:      Thu, 20 Nov 2014 17:36:25 +0000 (UTC)
From:      Gleb Smirnoff <glebius@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-projects@freebsd.org
Subject:   svn commit: r274754 - in projects/sendfile/sys: sys vm
Message-ID:  <201411201736.sAKHaPVD048634@svn.freebsd.org>
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Author: glebius
Date: Thu Nov 20 17:36:25 2014
New Revision: 274754
URL: https://svnweb.freebsd.org/changeset/base/274754

Log:
  o Since pager bufs are never put on freelist, share the space in
    the structure in union.
  o Add iodone callback pointer to the b_pager.
  o In vnode_pager use new b_pager.pg_iodone to store iodone
    pointer, eliminating the getpages_data structure and need to
    allocate it.
  
  Suggested by:	kib
  Sponsored by:	Netflix
  Sponsored by:	Nginx, Inc.

Modified:
  projects/sendfile/sys/sys/buf.h
  projects/sendfile/sys/vm/vnode_pager.c

Modified: projects/sendfile/sys/sys/buf.h
==============================================================================
--- projects/sendfile/sys/sys/buf.h	Thu Nov 20 17:31:25 2014	(r274753)
+++ projects/sendfile/sys/sys/buf.h	Thu Nov 20 17:36:25 2014	(r274754)
@@ -107,7 +107,6 @@ struct buf {
 	off_t	b_offset;		/* Offset into file. */
 	TAILQ_ENTRY(buf) b_bobufs;	/* (V) Buffer's associated vnode. */
 	uint32_t	b_vflags;	/* (V) BV_* flags */
-	TAILQ_ENTRY(buf) b_freelist;	/* (Q) Free list position inactive. */
 	unsigned short b_qindex;	/* (Q) buffer queue index */
 	uint32_t	b_flags;	/* B_* flags. */
 	b_xflags_t b_xflags;		/* extra flags */
@@ -124,9 +123,15 @@ struct buf {
 	struct	ucred *b_rcred;		/* Read credentials reference. */
 	struct	ucred *b_wcred;		/* Write credentials reference. */
 	void	*b_saveaddr;		/* Original b_addr for physio. */
-	union	pager_info {
-		int	pg_reqpage;
-	} b_pager;
+	union {
+		TAILQ_ENTRY(buf) bu_freelist; /* (Q) */
+		struct {
+			void	(*pg_iodone)(void *, vm_page_t *, int, int);
+			int	pg_reqpage;
+		} bu_pager;
+	} b_union;
+#define	b_freelist	b_union.bu_freelist
+#define	b_pager         b_union.bu_pager
 	union	cluster_info {
 		TAILQ_HEAD(cluster_list_head, buf) cluster_head;
 		TAILQ_ENTRY(buf) cluster_entry;

Modified: projects/sendfile/sys/vm/vnode_pager.c
==============================================================================
--- projects/sendfile/sys/vm/vnode_pager.c	Thu Nov 20 17:31:25 2014	(r274753)
+++ projects/sendfile/sys/vm/vnode_pager.c	Thu Nov 20 17:36:25 2014	(r274754)
@@ -77,15 +77,6 @@ __FBSDID("$FreeBSD$");
 #include <vm/vnode_pager.h>
 #include <vm/vm_extern.h>
 
-/*
- * Structure to pass state from vnode_pager_generic_getpages()
- * to vnode_pager_generic_getpages_done_async().
- */
-struct getpages_data {
-	void (*iodone)(void *, vm_page_t *, int, int);
-	void *arg;
-};
-
 static int vnode_pager_addr(struct vnode *vp, vm_ooffset_t address,
     daddr_t *rtaddress, int *run);
 static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m);
@@ -991,12 +982,8 @@ vnode_pager_generic_getpages(struct vnod
 	bp->b_iooffset = dbtob(bp->b_blkno);
 
 	if (iodone) { /* async */
-		struct getpages_data *d;
-
-		d = malloc(sizeof(*d), M_TEMP, M_WAITOK);
-		d->iodone = iodone;
-		d->arg = arg;
-		bp->b_caller1 = d;
+		bp->b_pager.pg_iodone = iodone;
+		bp->b_caller1 = arg;
 		bp->b_iodone = vnode_pager_generic_getpages_done_async;
 		bp->b_flags |= B_ASYNC;
 		BUF_KERNPROC(bp);
@@ -1020,17 +1007,16 @@ vnode_pager_generic_getpages(struct vnod
 static void
 vnode_pager_generic_getpages_done_async(struct buf *bp)
 {
-	struct getpages_data *d = bp->b_caller1;
 	int error;
 
 	error = vnode_pager_generic_getpages_done(bp);
-	d->iodone(d->arg, bp->b_pages, bp->b_pager.pg_reqpage, error);
+	bp->b_pager.pg_iodone(bp->b_caller1, bp->b_pages,
+	  bp->b_pager.pg_reqpage, error);
 	for (int i = 0; i < bp->b_npages; i++)
 		bp->b_pages[i] = NULL;
 	bp->b_vp = NULL;
 	pbrelbo(bp);
 	relpbuf(bp, &vnode_pbuf_freecnt);
-	free(d, M_TEMP);
 }
 
 static int

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