Messages in this thread | | | From | Nick Piggin <> | Subject | Re: [PATCH] VFS: make file->f_pos access atomic on 32bit arch | Date | Wed, 17 Sep 2008 11:24:14 +1000 |
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On Wednesday 17 September 2008 00:57, Michael Trimarchi wrote: > 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, 16:11:21 > > Oggetto: Re: [PATCH] VFS: make file->f_pos access atomic on 32bit arch > > ... > > > > 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 > > > > AFAIK, the only way to do an atomic 64 bit store on 32-bit x86 is > > "cmpxchg8b" (with lock prefix on SMP). That would be far slower > > I'm sure. > > Maybe it is clear with an example:
I understand and agree. -- 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/
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