Messages in this thread | | | Date | Tue, 16 Sep 2008 13:57:54 +0000 (GMT) | From | Michael Trimarchi <> | Subject | Re: [PATCH] VFS: make file->f_pos access atomic on 32bit arch |
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Hi,
----- Messaggio originale ----- > Da: Nick Piggin <nickpiggin@yahoo.com.au> > A: Michael Trimarchi <trimarchimichael@yahoo.it> > Cc: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>; akpm@linux-foundation.org; linux-kernel@vger.kernel.org; linux-fsdevel@vger.kernel.org > Inviato: Martedì 16 settembre 2008, 14:54:21 > Oggetto: Re: [PATCH] VFS: make file->f_pos access atomic on 32bit arch > > On Tuesday 16 September 2008 21:11, Michael Trimarchi wrote: > > Hi, > > > > > + if (offset != file_pos_read(file)) > > > + file_pos_write(file, offset); > > > retval = offset; > > > } > > > > Is not more efficient here a compare xchg operation? > > The compiler should do it if it was. > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
i was thinking about introducing a file_pos_update() not implemented using file_pos_read()/file_pos_write() and taking the seq_lock or disabling preemption only one time
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