July 2012 - Darwin-dev - lists.apple.com

Re: WrMeta
by Dave Keck 06 Jul '12

06 Jul '12

> Since this should be asynchronous, I'd be surprised if this is causing a significant performance degradation... Thanks Shantonu! -- it was indeed updating the access time. Is there a supported way to prevent my process from updating the access time? My initial benchmarks show a 28% performance increase in processing 4000 photos (82 seconds before, 64 seconds after). David _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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Re: WrMeta
by Shantonu Sen 06 Jul '12

06 Jul '12

It's a write of filesystem metadata. This is likely updates to the "atime" last accessed time for every file you enumerate, which causes writes to the HFS+ catalog (as well as journal when journaling is active). You can try an experiment to see if this is the case with: $ mount -t hfs | head -1 /dev/disk0s4 on / (hfs, local, journaled) $ sudo mount -t hfs -u -o noatime /dev/disk0s4 / $ mount -t hfs | head -1 /dev/disk0s4 on / (hfs, local, journaled, noatime) $ Since this should be asynchronous, I'd be surprised if this is causing a significant performance degradation... Shantonu On Jul 6, 2012, at 2:22 PM, Dave Keck <davekeck(a)gmail.com> wrote: > Hey list, > > I'm optimizing a program that reads image metadata using > CGImageSourceCreateWithURL(). This program should strictly read from > disk, but as it iterates over thousands of photos, the kernel is > writing data to disk at >1 MB/sec. fs_usage reports many instances of > the following: > > WrMeta[asyncP] D=0x... B=0x2000 /dev/disk... 0.097343 W kernel_task > > This is not the kernel paging-out to disk, as Activity Monitor reports > a constant value for "Page outs" for the lifetime of the program. > > What is 'WrMeta'? > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/darwin-dev/ssen%40apple.com > > This email sent to ssen(a)apple.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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WrMeta
by Dave Keck 06 Jul '12

06 Jul '12

Hey list, I'm optimizing a program that reads image metadata using CGImageSourceCreateWithURL(). This program should strictly read from disk, but as it iterates over thousands of photos, the kernel is writing data to disk at >1 MB/sec. fs_usage reports many instances of the following: WrMeta[asyncP] D=0x... B=0x2000 /dev/disk... 0.097343 W kernel_task This is not the kernel paging-out to disk, as Activity Monitor reports a constant value for "Page outs" for the lifetime of the program. What is 'WrMeta'? _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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Re: Write Finder Plugin in python
by Rakesh Singhal 02 Jul '12

02 Jul '12

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Re: Write Finder Plugin in python
by Nick Zitzmann 02 Jul '12

02 Jul '12

On Jul 2, 2012, at 5:26 AM, Rakesh Singhal wrote: > Hi All, > > This topic was discussed already but I am not very cleared that how to go ahead to implement a Finder plugin for Mac OS 10.6/10.7. I want to add items in Finder's Contextual menu. These menu items should be displayed only when I make right click on file/folders in a particular folder. Let me know if its possible to do it in python. I don't want to add items in Service. > > Please let me know if this list is not suitable for this question. You have to write a service; Finder CM plugin support was killed in favor of services in Snow Leopard. And the cocoa-dev list is a better place to inquire about writing services. Nick Zitzmann <http://www.chronosnet.com/> _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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Write Finder Plugin in python
by Rakesh Singhal 02 Jul '12

02 Jul '12

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