Thats interesting Ta, I thought it was enabled, I enabled the trim app and found that it slowed my machine down (noticeably) ...
Regards Ray On 31 Jan 2014, at 17:01, Sam - MacAmbulance <[email protected]> wrote: > I thought trim was enabled for apple SSDs only? > > Sam > > -- > MacAmbulance > Sam Mullen > 07747778022 > [email protected] > > On 31 Jan 2014, at 16:56, Graham Perrin <[email protected]> wrote: > >> On Thursday, 30 January 2014 22:54:33 UTC, Ray Packham wrote: >> >> ... I think the software is built into the SSD already ... >> >> Also - of possible interest to Sam and others with a technical mind - please >> note that there's support for TRIM within the operating system. >> >> From HFS-related source code for the kernel >> >> /* >> >> ;________________________________________________________________________________ >> >> ; >> ; Routine: hfs_unmap_free_extent >> ; >> ; Function: Make note of a range of allocation blocks that should be >> ; unmapped (trimmed). That is, the given range of blocks no >> ; longer have useful content, and the device can unmap the >> ; previous contents. For example, a solid state disk may >> reuse >> ; the underlying storage for other blocks. >> ; >> ; This routine is only supported for journaled volumes. The >> extent >> ; being freed is passed to the journal code, and the extent >> will >> ; be unmapped after the current transaction is written to >> disk. >> ; >> ; Input Arguments: >> ; hfsmp - The volume containing the allocation blocks. >> ; startingBlock - The first allocation block of the extent being >> freed. >> ; numBlocks - The number of allocation blocks of the extent being >> freed. >> >> ;________________________________________________________________________________ >> >> */ >> >> First appearance in Apple open source: >> http://www.opensource.apple.com/source/xnu/xnu-2050.9.2/bsd/hfs/hfscommon/Misc/VolumeAllocation.c >> (Mac OS X 10.8.1) >> >> Most recent appearance: >> http://www.opensource.apple.com/source/xnu/xnu-2422.1.72/bsd/hfs/hfscommon/Misc/VolumeAllocation.c >> >> >> Also, from the latter: >> >> /* >> * Validation Routine to verify that the TRIM list maintained by the journal >> * is in good shape relative to what we think the bitmap should have. We >> should >> * never encounter allocated blocks in the TRIM list, so if we ever >> encounter them, >> * we panic. >> */ >> >> ... >> >> /* >> >> ;________________________________________________________________________________ >> >> ; >> ; Routine: hfs_track_unmap_blocks >> ; >> ; Function: Make note of a range of allocation blocks that should be >> ; unmapped (trimmed). That is, the given range of blocks no >> ; longer have useful content, and the device can unmap the >> ; previous contents. For example, a solid state disk may >> reuse >> ; the underlying storage for other blocks. >> ; >> ; This routine is only supported for journaled volumes. >> ; >> ; *****NOTE*****: >> ; This function should *NOT* be used when the volume is fully >> ; mounted. This function is intended to support a bitmap >> iteration >> ; at mount time to fully inform the SSD driver of the state of >> all blocks >> ; at mount time, and assumes that there is no >> allocation/deallocation >> ; interference during its iteration., >> ; >> ; Input Arguments: >> ; hfsmp - The volume containing the allocation blocks. >> ; offset - The first allocation block of the extent being >> freed. >> ; numBlocks - The number of allocation blocks of the extent being >> freed. >> ; list - The list of currently tracked trim ranges. >> >> ;________________________________________________________________________________ >> >> */ >> >> ... and so on. >> >> Side note >> >> I stumbled across the relevant source code whilst seeking information about >> messages that are sent by the kernel in some situations. Within those >> messages, the following string: >> >> kernel[0]: hfs_unmap_free_ext: ignoring trim vol= >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Sussex Mac User Group" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send an email to [email protected]. >> Visit this group at http://groups.google.com/group/smug. >> For more options, visit https://groups.google.com/groups/opt_out. > > > -- > You received this message because you are subscribed to the Google Groups > "Sussex Mac User Group" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send an email to [email protected]. > Visit this group at http://groups.google.com/group/smug. > For more options, visit https://groups.google.com/groups/opt_out. Ray Packham [email protected] http://about.me/rpackham -- You received this message because you are subscribed to the Google Groups "Sussex Mac User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. Visit this group at http://groups.google.com/group/smug. For more options, visit https://groups.google.com/groups/opt_out.
