linux/arch/mips
Hugh Dickins 872fec16d9 [PATCH] mm: init_mm without ptlock
First step in pushing down the page_table_lock.  init_mm.page_table_lock has
been used throughout the architectures (usually for ioremap): not to serialize
kernel address space allocation (that's usually vmlist_lock), but because
pud_alloc,pmd_alloc,pte_alloc_kernel expect caller holds it.

Reverse that: don't lock or unlock init_mm.page_table_lock in any of the
architectures; instead rely on pud_alloc,pmd_alloc,pte_alloc_kernel to take
and drop it when allocating a new one, to check lest a racing task already
did.  Similarly no page_table_lock in vmalloc's map_vm_area.

Some temporary ugliness in __pud_alloc and __pmd_alloc: since they also handle
user mms, which are converted only by a later patch, for now they have to lock
differently according to whether or not it's init_mm.

If sources get muddled, there's a danger that an arch source taking
init_mm.page_table_lock will be mixed with common source also taking it (or
neither take it).  So break the rules and make another change, which should
break the build for such a mismatch: remove the redundant mm arg from
pte_alloc_kernel (ppc64 scrapped its distinct ioremap_mm in 2.6.13).

Exceptions: arm26 used pte_alloc_kernel on user mm, now pte_alloc_map; ia64
used pte_alloc_map on init_mm, now pte_alloc_kernel; parisc had bad args to
pmd_alloc and pte_alloc_kernel in unused USE_HPPA_IOREMAP code; ppc64
map_io_page forgot to unlock on failure; ppc mmu_mapin_ram and ppc64 im_free
took page_table_lock for no good reason.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29 21:40:40 -07:00
..
arc IP30 Identification. 2005-10-29 19:31:39 +01:00
au1000 Remove useless casts of kmalloc return values. 2005-10-29 19:32:50 +01:00
boot commit 1858f72fa2e2f63e62114a9bd40c8e68468d8c5e 2005-10-29 19:31:56 +01:00
cobalt Resurrect Cobalt support for 2.6. 2005-10-29 19:30:42 +01:00
configs Update MIPS defconfig files. 2005-10-29 19:32:54 +01:00
ddb5xxx Sliceup Kconfig; it's grown too large. 2005-10-29 19:32:41 +01:00
dec Make static what ought to be static. 2005-10-29 19:32:12 +01:00
galileo-boards/ev96100 Get rid of early_init. There's more need to make this form of 2005-10-29 19:30:18 +01:00
gt64120 Sliceup Kconfig; it's grown too large. 2005-10-29 19:32:41 +01:00
ite-boards Sliceup Kconfig; it's grown too large. 2005-10-29 19:32:41 +01:00
jazz Sliceup Kconfig; it's grown too large. 2005-10-29 19:32:41 +01:00
jmr3927 Use new txx9 serial driver. 2005-10-29 19:30:52 +01:00
kernel [PATCH] mm: mm_init set_mm_counters 2005-10-29 21:40:38 -07:00
lasat Sliceup Kconfig; it's grown too large. 2005-10-29 19:32:41 +01:00
lib Hack to resolve longstanding prefetch issue 2005-10-29 19:32:50 +01:00
lib-32 Fixup a few lose ends in explicit support for MIPS R1/R2. 2005-10-29 19:32:37 +01:00
lib-64 Fixup a few lose ends in explicit support for MIPS R1/R2. 2005-10-29 19:32:37 +01:00
math-emu Get rid of SINGLE_ONLY_FPU. Linux does not support half FPU other than 2005-10-29 19:32:52 +01:00
mips-boards Support for MIPSsim, the cycle accurate MIPS simulator. 2005-10-29 19:32:30 +01:00
mm [PATCH] mm: init_mm without ptlock 2005-10-29 21:40:40 -07:00
momentum prom_free_prom_memory() returns unsigned long 2005-10-29 19:32:53 +01:00
oprofile Fixup a few lose ends in explicit support for MIPS R1/R2. 2005-10-29 19:32:37 +01:00
pci pci-expmem-hack 2005-10-29 19:32:49 +01:00
philips/pnx8550 Philips PNX8550 support: MIPS32-like core with 2 Trimedias on it. 2005-10-29 19:31:54 +01:00
pmc-sierra prom_free_prom_memory() returns unsigned long 2005-10-29 19:32:53 +01:00
qemu Implement get_system_type() for Qemu to get procfs-enabled kernels to 2005-10-29 19:32:02 +01:00
sgi-ip22 IP22 EISA support update. 2005-10-29 19:32:13 +01:00
sgi-ip27 Use pr_debug instead of homegrown debug print macros. 2005-10-29 19:32:00 +01:00
sgi-ip32 Convert struct hw_interrupt_type initializations to ISO C99 named 2005-10-29 19:30:46 +01:00
sibyte SB1 cache exception handling. 2005-10-29 19:32:48 +01:00
sni Convert struct hw_interrupt_type initializations to ISO C99 named 2005-10-29 19:30:46 +01:00
tx4927 Sliceup Kconfig; it's grown too large. 2005-10-29 19:32:41 +01:00
tx4938 Support for Toshiba's RBHMA4500 eval board for the TX4938. 2005-10-29 19:31:57 +01:00
vr41xx Sliceup Kconfig; it's grown too large. 2005-10-29 19:32:41 +01:00
defconfig Update MIPS defconfig files. 2005-10-29 19:32:54 +01:00
Kconfig More foolproofing of the CPU configuration. 2005-10-29 19:32:49 +01:00
Kconfig.debug Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile Support for BigSur board. 2005-10-29 19:32:47 +01:00