Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Peter Zijlstra
authored
Instead of caching the reloc for each instruction, only keep a
negative cache of not having a reloc (by far the most common case).
struct instruction {
struct list_head list; /* 0 16 */
struct hlist_node hash; /* 16 16 */
struct list_head call_node; /* 32 16 */
struct section * sec; /* 48 8 */
long unsigned int offset; /* 56 8 */
/* --- cacheline 1 boundary (64 bytes) --- */
long unsigned int immediate; /* 64 8 */
unsigned int len; /* 72 4 */
u8 type; /* 76 1 */
/* Bitfield combined with previous fields */
u16 dead_end:1; /* 76: 8 2 */
u16 ignore:1; /* 76: 9 2 */
u16 ignore_alts:1; /* 76:10 2 */
u16 hint:1; /* 76:11 2 */
u16 save:1; /* 76:12 2 */
u16 restore:1; /* 76:13 2 */
u16 retpoline_safe:1; /* 76:14 2 */
u16 noendbr:1; /* 76:15 2 */
u16 entry:1; /* 78: 0 2 */
u16 visited:4; /* 78: 1 2 */
+ u16 no_reloc:1; /* 78: 5 2 */
- /* XXX 3 bits hole, try to pack */
+ /* XXX 2 bits hole, try to pack */
/* Bitfield combined with next fields */
s8 instr; /* 79 1 */
struct alt_group * alt_group; /* 80 8 */
struct symbol * call_dest; /* 88 8 */
struct instruction * jump_dest; /* 96 8 */
struct instruction * first_jump_src; /* 104 8 */
struct reloc * jump_table; /* 112 8 */
- struct reloc * reloc; /* 120 8 */
+ struct alternative * alts; /* 120 8 */
/* --- cacheline 2 boundary (128 bytes) --- */
- struct alternative * alts; /* 128 8 */
- struct symbol * sym; /* 136 8 */
- struct stack_op * stack_ops; /* 144 8 */
- struct cfi_state * cfi; /* 152 8 */
+ struct symbol * sym; /* 128 8 */
+ struct stack_op * stack_ops; /* 136 8 */
+ struct cfi_state * cfi; /* 144 8 */
- /* size: 160, cachelines: 3, members: 29 */
- /* sum members: 158 */
- /* sum bitfield members: 13 bits, bit holes: 1, sum bit holes: 3 bits */
- /* last cacheline: 32 bytes */
+ /* size: 152, cachelines: 3, members: 29 */
+ /* sum members: 150 */
+ /* sum bitfield members: 14 bits, bit holes: 1, sum bit holes: 2 bits */
+ /* last cacheline: 24 bytes */
};
pre: 5:48.89 real, 220.96 user, 127.55 sys, 24834672 mem
post: 5:39.35 real, 215.58 user, 123.69 sys, 23448736 mem
Signed-off-by: 
Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: 
Ingo Molnar <mingo@kernel.org>
Acked-by: 
Josh Poimboeuf <jpoimboe@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org> # build only
Tested-by: Thomas Weißschuh <linux@weissschuh.net> # compile and run
Link: https://lore.kernel.org/r/20230208172245.572145269@infradead.org