Messages in this thread Patch in this message | | | From | (Eric W. Biederman) | Subject | [PATCH] sysctl: Undeprecate sys_sysctl (take 2) | Date | Wed, 08 Nov 2006 12:58:35 -0700 |
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The basic issue is that despite have been ``deprecated'' and warned about as a very bad thing in the man pages since it's inception there are a few real users of sys_sysctl. It was my assumption that because sysctl had been ``deprecated'' for all of 2.6 there would be no user space users by this point, so I initially gave sys_sysctl a very short deprecation period.
Now that I know there are a few real users the only sane way to proceed with deprecation is to push the time limit out to a year or two work and work with distributions that have big testing pools like fedora core to find these last remaining users.
Which means that the sys_sysctl interface needs to be maintained in the meantime.
Since I have provided a technical measure that allows us to add new sysctl entries without reserving more binary numbers I believe that is enough to fix the sys_sysctl binary interface maintenance problems (I.e. don't grow it any more).
Since the sys_sysctl implementation needs to stay around for a while and the worst of the maintenance issues that caused us to occassionally break the ABI have been addressed I don't see any advantage in continuing with the removal of sys_sysctl.
With committing to maintain sys_sysctl we get all of the advantages of a fast interface for anything that needs it. Currently sys_sysctl is about 5x faster than /proc/sys, for the same string data.
The Kconfig help text is now also fixed.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> --- Documentation/feature-removal-schedule.txt | 12 ------------ init/Kconfig | 19 +++++++++---------- 2 files changed, 9 insertions(+), 22 deletions(-)
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 1ac3c74..d52c4aa 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -53,18 +53,6 @@ Who: Mauro Carvalho Chehab <mchehab@brtu --------------------------- -What: sys_sysctl -When: January 2007 -Why: The same information is available through /proc/sys and that is the - interface user space prefers to use. And there do not appear to be - any existing user in user space of sys_sysctl. The additional - maintenance overhead of keeping a set of binary names gets - in the way of doing a good job of maintaining this interface. - -Who: Eric Biederman <ebiederm@xmission.com> - ---------------------------- - What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl]) When: November 2005 Files: drivers/pcmcia/: pcmcia_ioctl.c diff --git a/init/Kconfig b/init/Kconfig index c8b2624..ffe945a 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -304,20 +304,19 @@ config UID16 config SYSCTL_SYSCALL bool "Sysctl syscall support" if EMBEDDED - default n + default y select SYSCTL ---help--- - Enable the deprecated sysctl system call. sys_sysctl uses - binary paths that have been found to be a major pain to maintain - and use. The interface in /proc/sys is now the primary and what - everyone uses. + sys_sysctl uses binary paths that have been found challenging + to properly maintain and use. The interface in /proc/sys + using paths with ascii names is now the primary path to this + information. - Nothing has been using the binary sysctl interface for some - time now so nothing should break if you disable sysctl syscall - support, and your kernel will get marginally smaller. + Almost nothing using the binary sysctl interface so if you are + trying to save some space it is probably safe to disable this, + making your kernel marginally smaller. - Unless you have an application that uses the sys_sysctl interface - you should probably say N here. + If unsure say Y here. config KALLSYMS bool "Load all symbols for debugging/kksymoops" if EMBEDDED -- 1.4.2.rc3.g7e18e-dirty - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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