Re: CVS commit: src/sys

[Frank Kardel <kardel%netbsd.org@localhost>]

Hi !

As I already observed in another reply to a doc change referring to 
these changes.
I have narrowed down the time frame where fdesc handling broke (at least 
for cups and its filter pipes).

A kernel before 2009-05-23 22:00:00 works - a kernel after 2009-05-24 
22:00:00 kills cups filter pipes
with the foomatic perl script tripping over an EBADF in STDIN. Also cups 
CGI communication breaks.

It seems to be that this change may have some corner cases worth to be 
examined.

Frank

-Andrew Doran wrote:
> Module Name:    src
> Committed By:   ad
> Date:           Sun May 24 21:41:26 UTC 2009
>
> Modified Files:
>         src/sys/compat/netbsd32: netbsd32_ioctl.c
>         src/sys/compat/svr4: svr4_filio.c
>         src/sys/compat/svr4_32: svr4_32_filio.c
>         src/sys/ddb: db_xxx.c
>         src/sys/kern: init_sysctl.c kern_descrip.c kern_event.c kern_sig.c
>             subr_exec_fd.c sys_aio.c sys_descrip.c sys_generic.c sys_select.c
>             uipc_usrreq.c
>         src/sys/miscfs/fdesc: fdesc_vfsops.c fdesc_vnops.c
>         src/sys/miscfs/portal: portal_vnops.c
>         src/sys/miscfs/procfs: procfs_vnops.c
>         src/sys/sys: filedesc.h
>
> Log Message:
> More changes to improve kern_descrip.c.
>
> - Avoid atomics in more places.
> - Remove the per-descriptor mutex, and just use filedesc_t::fd_lock.
>   It was only being used to synchronize close, and in any case we needed
>   to take fd_lock to free the descriptor slot.
> - Optimize certain paths for the <NDFDFILE case.
> - Sprinkle more comments and assertions.
> - Cache more stuff in filedesc_t.
> - Fix numerous minor bugs spotted along the way.
> - Restructure how the open files array is maintained, for clarity and so
>   that we can eliminate the membar_consumer() call in fd_getfile().  This is
>   mostly syntactic sugar; the main functional change is that fd_nfiles now
>   lives alongside the open file array.
>
> Some measurements with libmicro:
>
> - simple file syscalls are like close() are between 1 to 10% faster.
> - some nice improvements, e.g. poll(1000) which is ~50% faster.
>
>
> To generate a diff of this commit:
> cvs rdiff -u -r1.41 -r1.42 src/sys/compat/netbsd32/netbsd32_ioctl.c
> cvs rdiff -u -r1.22 -r1.23 src/sys/compat/svr4/svr4_filio.c
> cvs rdiff -u -r1.16 -r1.17 src/sys/compat/svr4_32/svr4_32_filio.c
> cvs rdiff -u -r1.60 -r1.61 src/sys/ddb/db_xxx.c
> cvs rdiff -u -r1.163 -r1.164 src/sys/kern/init_sysctl.c
> cvs rdiff -u -r1.191 -r1.192 src/sys/kern/kern_descrip.c
> cvs rdiff -u -r1.64 -r1.65 src/sys/kern/kern_event.c
> cvs rdiff -u -r1.297 -r1.298 src/sys/kern/kern_sig.c
> cvs rdiff -u -r1.1 -r1.2 src/sys/kern/subr_exec_fd.c
> cvs rdiff -u -r1.23 -r1.24 src/sys/kern/sys_aio.c
> cvs rdiff -u -r1.12 -r1.13 src/sys/kern/sys_descrip.c
> cvs rdiff -u -r1.122 -r1.123 src/sys/kern/sys_generic.c
> cvs rdiff -u -r1.14 -r1.15 src/sys/kern/sys_select.c
> cvs rdiff -u -r1.125 -r1.126 src/sys/kern/uipc_usrreq.c
> cvs rdiff -u -r1.79 -r1.80 src/sys/miscfs/fdesc/fdesc_vfsops.c
> cvs rdiff -u -r1.106 -r1.107 src/sys/miscfs/fdesc/fdesc_vnops.c
> cvs rdiff -u -r1.82 -r1.83 src/sys/miscfs/portal/portal_vnops.c
> cvs rdiff -u -r1.173 -r1.174 src/sys/miscfs/procfs/procfs_vnops.c
> cvs rdiff -u -r1.54 -r1.55 src/sys/sys/filedesc.h
>
> Please note that diffs are not public domain; they are subject to the
> copyright notices on the relevant files.
>