CVS commit: syssrc

[Jason R Thorpe <thorpej%netbsd.org@localhost>]

Module Name:    syssrc
Committed By:   thorpej
Date:           Wed May 26 06:42:58 UTC 1999

Modified Files:
        syssrc/sys/uvm: uvm_pager.c

Log Message:
In uvm_pagermapin(), pass VM_PROT_READ|VM_PROT_WRITE as access_type, to
ensure we don't take mod/ref emulation faults in an interrupt context
(e.g. during the i/o operation).  This is safe because:
        - For a pageout operation, the page is already known to be
          modified, and the pagedaemon will pmap_clear_modify() after
          the pageout has completed.
        - For a pagein operation, pagers must already pmap_clear_modify()
          after the pagein operation is complete, because the i/o may have
          been done with e.g. programmed i/o.
XXX It would be nice to know the i/o direction so that we can call
XXX pmap_enter() with only the protection and access_type necessary.


To generate a diff of this commit:
cvs rdiff -r1.18 -r1.19 syssrc/sys/uvm/uvm_pager.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.