Date: Wed, 25 Feb 2009 07:52:54 +0000 (UTC) From: Alan Cox <alc@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r189024 - head/sys/vm Message-ID: <200902250752.n1P7qsDj088699@svn.freebsd.org>
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Author: alc Date: Wed Feb 25 07:52:53 2009 New Revision: 189024 URL: http://svn.freebsd.org/changeset/base/189024 Log: Prior to r188331 a map entry's last read offset was only updated by a hard fault. In r188331 this update was relocated because of synchronization changes to a place where it would occur on both hard and soft faults. This change again restricts the update to hard faults. Modified: head/sys/vm/vm_fault.c Modified: head/sys/vm/vm_fault.c ============================================================================== --- head/sys/vm/vm_fault.c Wed Feb 25 01:49:01 2009 (r189023) +++ head/sys/vm/vm_fault.c Wed Feb 25 07:52:53 2009 (r189024) @@ -868,13 +868,17 @@ vnode_locked: } } /* - * update lastr imperfectly (we do not know how much - * getpages will actually read), but good enough. + * If the page was filled by a pager, update the map entry's + * last read offset. Since the pager does not return the + * actual set of pages that it read, this update is based on + * the requested set. Typically, the requested and actual + * sets are the same. * * XXX The following assignment modifies the map * without holding a write lock on it. */ - fs.entry->lastr = fs.pindex + faultcount - behind; + if (hardfault) + fs.entry->lastr = fs.pindex + faultcount - behind; if (prot & VM_PROT_WRITE) { vm_object_set_writeable_dirty(fs.object);
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