Bill Davidsen wrote:
How about anything more? The truth is that much common hardware doesn't really make the cache to disk move visible, and turning off cache really hurts performance. And it would appear that fsync force a lot more data out of memory than just the blocks for the file in question.
Correct. That's the tradeoff with the ATA interface: you must be aware of the cache flush requirements when designing a solution such as a database that really cares about fsync(2), or a journalling filesystem.
However, the point I was making is that it would be useful to be able to tell when the write to non-volatile took place, not to force that to happen. Not to do anything which would flush a lot of other stuff and busy the drive. What I suggest is NOT fsync, just a way to assure ordering.
To make that possible, POSIX must become a transactional, async I/O API... :)
Jeff - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
- References:
- Re: Disk write cache (Was: Hyper-Threading Vulnerability)
- From: Jeff Garzik <[email protected]>
- Re: Disk write cache
- From: Kenichi Okuyama <[email protected]>
- Re: Disk write cache
- From: Jeff Garzik <[email protected]>
- Linux does not care for data integrity (was: Disk write cache)
- From: Matthias Andree <[email protected]>
- Re: Linux does not care for data integrity (was: Disk write cache)
- From: Arjan van de Ven <[email protected]>
- Re: Linux does not care for data integrity (was: Disk write cache)
- From: Matthias Andree <[email protected]>
- Re: Linux does not care for data integrity (was: Disk write cache)
- From: Arjan van de Ven <[email protected]>
- Re: Linux does not care for data integrity (was: Disk write cache)
- From: Matthias Andree <[email protected]>
- Re: Linux does not care for data integrity (was: Disk write cache)
- From: Alan Cox <[email protected]>
- Re: Linux does not care for data integrity (was: Disk write cache)
- From: Greg Stark <[email protected]>
- Re: Linux does not care for data integrity (was: Disk write cache)
- From: Matthias Andree <[email protected]>
- Re: Linux does not care for data integrity
- From: Bill Davidsen <[email protected]>
- Re: Linux does not care for data integrity
- From: Jeff Garzik <[email protected]>
- Re: Linux does not care for data integrity
- From: Bill Davidsen <[email protected]>
- Re: Disk write cache (Was: Hyper-Threading Vulnerability)
- Prev by Date: Re: [PATCH] Dynamic tick for x86 version 050602-1
- Next by Date: Re: [PATCH] Dynamic tick for x86 version 050602-1
- Previous by thread: Re: Linux does not care for data integrity
- Next by thread: Re: Linux does not care for data integrity
- Index(es):
 |