Messages in this thread | | | Date | Mon, 24 May 1999 19:25:06 +0200 | From | Manfred Spraul <> | Subject | Re: [patch] releasing kernel lock during copy_from/to_user |
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I've modified uaccess.h, and I have now a list of all functions which called copy_to/from_user() for more than 512 bytes (apache, make clean; make fs; find /usr/bin)
* read_file_actor() * ext2_file_write() * block_read() * copy_mount_options() << really rare * proc_file_read() << rare?? * pipe_write() * pipe_read() * 2*vt_ioctl() << could be remote gdb. * tcp_do_sendmsg() * copy_strings() << only during fork()?
Additionally, the following functions should also release the kernel lock: * padzero() in binfmt_elf: This function clears up to 4096 bytes user memory. The average should be 2048. * update_vm_mapping(): the function can wait in wait_on_page(), we should break nothing * get_free_page(): if GFP_WAIT, for memset(,0,PAGE_SIZE)
Are you aware of other functions which could release the lock for long operations?
I'll extract the patch from andrea5, but I'll release the lock only in the codepath's where I have seen > 512 bytes.
A compile-time check is faster than the shortest runtime check:>
I'll post benchmarks later. -- Manfred
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