kernel/linux.git/scripts/kconfig/symbol.c, branch linux-2.6.35.y

kconfig: recalc symbol value before showing search results

2010-03-23T11:29:07+00:00

A symbol's value won't be recalc-ed until we save config file or enter the menu where the symbol sits. So If I enable OPTIMIZE_FOR_SIZE, and search FUNCTION_GRAPH_TRACER: Symbol: FUNCTION_GRAPH_TRACER [=y] Prompt: Kernel Function Graph Tracer Defined at kernel/trace/Kconfig:140 Depends on: ... [=y] && (!X86_32 [=y] || !CC_OPTIMIZE_FOR_SIZE [=y]) ... From the dependency it should result in FUNCTION_GRAPH_TRACER=n, but it still shows FUNCTION_GRAPH_TRACER=y. Signed-off-by: Li Zefan Signed-off-by: Michal Marek

Improve kconfig symbol hashing

2010-02-02T13:33:55+00:00

While looking for something else I noticed that the symbol hash function used by kconfig is quite poor. It doesn't use any of the standard hash techniques but simply adds up the string and then uses power of two masking, which is both known to perform poorly. The current x86 kconfig has over 7000 symbols. When I instrumented it showed that the minimum hash chain length was 16 and a significant number of them was over 30. It didn't help that the hash table size was only 256 buckets. This patch increases the hash table size to a larger prime and switches to a FNV32 hash. I played around with a couple of hash functions, but that one seemed to perform best with reasonable hash table sizes. Increasing the hash table size even further didn't seem like a good idea, because there are a couple of global walks which walk the complete hash table. I also moved the unnamed bucket to 0. It's still the longest of all the buckets (44 entries), but hopefully it's not often hit except for the global walk which doesn't care. The result is a much nicer distribution: (first column bucket length, second number of buckets with that length) 1: 3505 2: 1236 3: 294 4: 52 5: 3 47: 1 <--- this is the unnamed symbols bucket There are still some 5+ buckets, but increasing the hash table even more would be likely not worth it. This also cleans up the code slightly by removing hard coded magic numbers. I didn't notice a big performance difference either way on my Nehalem system, but I presume it'll help somewhat on slower systems. Signed-off-by: Andi Kleen Signed-off-by: Michal Marek

kbuild: add static to prototypes

2009-09-20T10:27:44+00:00

Warnings found via gcc -Wmissing-prototypes. Signed-off-by: Trevor Keith Acked-by: WANG Cong Signed-off-by: Andrew Morton Signed-off-by: Sam Ravnborg

kconfig: add named choice group

2008-04-28T21:05:48+00:00

As choice dependency are now fully checked, it's quite easy to add support for named choices. This lifts the restriction that a choice value can only appear once, although it still has to be within the same group, but multiple choices can be joined by giving them a name. While at it I cleaned up a little the choice type logic to simplify it a bit. Signed-off-by: Roman Zippel Signed-off-by: Sam Ravnborg

kconfig: fix choice dependency check

2008-04-28T21:04:57+00:00

Properly check the dependency of choices as a group. Also fix that sym_check_deps() correctly terminates the dependency loop error check (otherwise it would continue printing the dependency chain). Signed-off-by: Roman Zippel Signed-off-by: Sam Ravnborg

kconfig: fix select in combination with default

2008-02-13T21:30:09+00:00

> The attached .config (with current -git) results in a compile > error since it contains: > > CONFIG_X86=y > # CONFIG_EMBEDDED is not set > CONFIG_SERIO=m > CONFIG_SERIO_I8042=y > > Looking at drivers/input/serio/Kconfig I simply don't get how this > can happen. You've hit the rather subtle rules of select vs default. What happened is that SERIO is selected to m, but SERIO_I8042 isn't selected so the default of y is used instead. We already had the problem in the past that select and default don't work well together, so this patch cleans this up and makes the rule hopefully more straightforward. Basically now the value is calculated like this: (value && dependency) || select where the value is the user choice (if available and the symbol is visible) or default. In this case it means SERIO and SERIO_I8042 are both set to y due to their default and if SERIO didn't had the default, then the SERIO_I8042 value would be limited to m due to the dependency. I tested this patch with more 10000 random configs and above case is the only the difference that showed up, so I hope there is nothing that depended on the old more complex and subtle rules. Signed-off-by: Roman Zippel Tested-by: Adrian Bunk Signed-off-by: Sam Ravnborg

kconfig: use environment option

2008-01-28T22:14:39+00:00

Use the environment option to provide the ARCH symbol and the KERNELVERSION symbol. Signed-off-by: Roman Zippel Signed-off-by: Sam Ravnborg

kconfig: environment symbol support

2008-01-28T22:14:39+00:00

Add the possibility to import a value from the environment into kconfig via the option syntax. Beside flexibility this has the advantage providing proper dependencies. Documented the options syntax. Signed-off-by: Roman Zippel Signed-off-by: Sam Ravnborg

kconfig: explicitly introduce expression list

2008-01-28T22:14:39+00:00

Rename E_CHOICE to E_LIST to explicitly add support for expression lists. Add a helper macro expr_list_for_each_sym to more easily iterate over the list. Signed-off-by: Roman Zippel Signed-off-by: Sam Ravnborg

kconfig: rename E_OR & friends to avoid name clash

2008-01-28T22:14:38+00:00

We had macros named the same as a set of enumeration values. It is legal code but very confusing to read - so rename the macros from E_* to EXPR_* Signed-off-by: Sam Ravnborg Cc: Roman Zippel