X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Ffilesys.texi;h=9075c9a5a3c2f113319b980fb205bba596d00b2a;hb=a96d2712f349629d7fe2186e2620f1704cbdee50;hp=83900ce2fbf4f9e708aeff6fdca49cb9c997a2e8;hpb=7641b4a058aedefcf6430000ec7742881f9e2a9f;p=pintos-anon diff --git a/doc/filesys.texi b/doc/filesys.texi index 83900ce..9075c9a 100644 --- a/doc/filesys.texi +++ b/doc/filesys.texi @@ -259,8 +259,8 @@ false if it represents an ordinary file. @end deftypefn @deftypefn {System Call} int inumber (int @var{fd}) -Returns the @dfn{inode number} of the inode associated with @var{fd}. -Applicable to file descriptors for both files and directories. +Returns the @dfn{inode number} of the inode associated with @var{fd}, +which may represent an ordinary file or a directory. An inode number persistently identifies a file or directory. It is unique during the file's existence. In Pintos, the sector number of the @@ -311,11 +311,8 @@ blocks back to disk. The cache should also be written back to disk in @func{filesys_done}, so that halting Pintos flushes the cache. If you have @func{timer_sleep} from the first project working, write-behind is -an excellent application. If you're still using the base -implementation of @func{timer_sleep}, be aware that it busy-waits, which -is not acceptable here (or elsewhere). If @func{timer_sleep}'s delays seem too -short or too long, reread the explanation of the @option{-r} option to -@command{pintos} (@pxref{Debugging versus Testing}). +an excellent application. Otherwise, you may implement a less general +facility, but make sure that it does not exhibit busy-waiting. You should also implement @dfn{read-ahead}, that is, automatically fetch the next block of a file