On Thu, 2012-04-19 at 01:02 +1000, James Morris wrote: > On Wed, 18 Apr 2012, Mimi Zohar wrote: > > > Hi James, > > > > As the last IMA-appraisal posting on 3/29 addressed Al's > > performance/maintenance concerns of deferring the __fput() and there > > hasn't been any additional comments, please consider pulling the > > IMA-appraisal patches. > > I thought Dmitry was still waiting on comments from Al for this. Al NAK'ed the original 'ima: defer calling __fput()' patch from 3/22, but we addressed both of Al's performance and maintaince concerns in the last posting on 3/29, which was three weeks ago. We haven't heard back ... >From the 'ima: defer calling __fput()' patch description: ima_file_free(), which is called on __fput(), updates the file data hash stored as an extended attribute to reflect file changes. If a file is closed before it is munmapped, __fput() is called with the mmap_sem taken. With IMA-appraisal enabled, this results in an mmap_sem/i_mutex lockdep. ima_defer_fput() increments the f_count to defer the __fput() being called until after the mmap_sem is released. The number of __fput() calls needing to be deferred is minimal. Only those files in policy, that were closed prior to the munmap and were mmapped write, need to defer the __fput(). With this patch, on a clean F16 install, from boot to login, only 5 out of ~100,000 mmap_sem held fput() calls were deferred. Changelog v4: - ima_defer_fput() performance improvements - move ima_defer_fput() call from remove_vma() to __fput() - only defer mmapped files opened for write - remove unnecessary ima_fput_mempool_destroy() Mimi -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
