02 Aug, 2008
1 commit
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* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (28 commits)
mm/hugetlb.c must #include
video: Fix up hp6xx driver build regressions.
sh: defconfig updates.
sh: Kill off stray mach-rsk7203 reference.
serial: sh-sci: Fix up SH7760/SH7780/SH7785 early printk regression.
sh: Move out individual boards without mach groups.
sh: Make sure AT_SYSINFO_EHDR is exposed to userspace in asm/auxvec.h.
sh: Allow SH-3 and SH-5 to use common headers.
sh: Provide common CPU headers, prune the SH-2 and SH-2A directories.
sh/maple: clean maple bus code
sh: More header path fixups for mach dir refactoring.
sh: Move out the solution engine headers to arch/sh/include/mach-se/
sh: I2C fix for AP325RXA and Migo-R
sh: Shuffle the board directories in to mach groups.
sh: dma-sh: Fix up dreamcast dma.h mach path.
sh: Switch KBUILD_DEFCONFIG to shx3_defconfig.
sh: Add ARCH_DEFCONFIG entries for sh and sh64.
sh: Fix compile error of Solution Engine
sh: Proper __put_user_asm() size mismatch fix.
sh: Stub in a dummy ENTRY_OFFSET for uImage offset calculation.
...
01 Aug, 2008
1 commit
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For anonymous pages without a swap cache backing the check in
page_remove_rmap for the physical dirty bit in page_remove_rmap is
unnecessary. The instructions that are used to check and reset the dirty
bit are expensive. Removing the check noticably speeds up process exit.
In addition the clearing of the dirty bit in __SetPageUptodate is
pointless as well. With these two changes there is no storage key
operation for an anonymous page anymore if it does not hit the swap
space.The micro benchmark which repeatedly executes an empty shell script
gets about 5% faster.Signed-off-by: Martin Schwidefsky
31 Jul, 2008
9 commits
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The iov_iter_advance() function would look at the iov->iov_len entry
even though it might have iterated over the whole array, and iov was
pointing past the end. This would cause DEBUG_PAGEALLOC to trigger a
kernel page fault if the allocation was at the end of a page, and the
next page was unallocated.The quick fix is to just change the order of the tests: check that there
is any iovec data left before we check the iov entry itself.Thanks to Alexey Dobriyan for finding this case, and testing the fix.
Reported-and-tested-by: Alexey Dobriyan
Cc: Nick Piggin
Cc: Andrew Morton
Cc: [2.6.25.x, 2.6.26.x]
Signed-off-by: Linus Torvalds -
Exports needed by the GRU driver.
Signed-off-by: Jack Steiner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
zap_vma_ptes() is intended to be used by drivers to unmap ptes assigned to the
driver private vmas. This interface is similar to zap_page_range() but is
less general & less likely to be abused.Needed by the GRU driver.
Signed-off-by: Jack Steiner
Cc: Nick Piggin
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Fernando Luis Vazquez Cao
Cc: Hugh Dickins
Cc: Nick Piggin
Cc: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Fernando Luis Vazquez Cao
Cc: Hugh Dickins
Cc: Nick Piggin
Cc: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Fernando Luis Vazquez Cao
Cc: Hugh Dickins
Cc: Nick Piggin
Cc: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Fernando Luis Vazquez Cao
Cc: Hugh Dickins
Cc: Nick Piggin
Cc: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It's guaranteed by cgroup that old_cgrp != cgrp.
Signed-off-by: Li Zefan
Cc: Paul Menage
Cc: Cedric Le Goater
Cc: Balbir Singh
Acked-by: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It has no user now
Also print out info about adding/removing active regions.
Signed-off-by: Yinghai Lu
Acked-by: Mel Gorman
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Jul, 2008
1 commit
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This patch fixes the following build error on sh caused by
commit aa888a74977a8f2120ae9332376e179c39a6b07d
(hugetlb: support larger than MAX_ORDER):...
CC mm/hugetlb.o
/home/bunk/linux/kernel-2.6/git/linux-2.6/mm/hugetlb.c: In function 'alloc_bootmem_huge_page':
/home/bunk/linux/kernel-2.6/git/linux-2.6/mm/hugetlb.c:958: error: implicit declaration of function 'virt_to_phys'
make[2]: *** [mm/hugetlb.o] Error 1Reported-by: Adrian Bunk
Signed-off-by: Adrian Bunk
Signed-off-by: Paul Mundt
29 Jul, 2008
5 commits
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When we read some part of a file through pagecache, if there is a
pagecache of corresponding index but this page is not uptodate, read IO
is issued and this page will be uptodate.I think this is good for pagesize == blocksize environment but there is
room for improvement on pagesize != blocksize environment. Because in
this case a page can have multiple buffers and even if a page is not
uptodate, some buffers can be uptodate.So I suggest that when all buffers which correspond to a part of a file
that we want to read are uptodate, use this pagecache and copy data from
this pagecache to user buffer even if a page is not uptodate. This can
reduce read IO and improve system throughput.I wrote a benchmark program and got result number with this program.
This benchmark do:
1: mount and open a test file.
2: create a 512MB file.
3: close a file and umount.
4: mount and again open a test file.
5: pwrite randomly 300000 times on a test file. offset is aligned
by IO size(1024bytes).6: measure time of preading randomly 100000 times on a test file.
The result was:
2.6.26
330 sec2.6.26-patched
226 secArch:i386
Filesystem:ext3
Blocksize:1024 bytes
Memory: 1GBOn ext3/4, a file is written through buffer/block. So random read/write
mixed workloads or random read after random write workloads are optimized
with this patch under pagesize != blocksize environment. This test result
showed this.The benchmark program is as follows:
#include
#include
#include
#include
#include
#include
#include
#include
#include#define LEN 1024
#define LOOP 1024*512 /* 512MB */main(void)
{
unsigned long i, offset, filesize;
int fd;
char buf[LEN];
time_t t1, t2;if (mount("/dev/sda1", "/root/test1/", "ext3", 0, 0) < 0) {
perror("cannot mount\n");
exit(1);
}
memset(buf, 0, LEN);
fd = open("/root/test1/testfile", O_CREAT|O_RDWR|O_TRUNC);
if (fd < 0) {
perror("cannot open file\n");
exit(1);
}
for (i = 0; i < LOOP; i++)
write(fd, buf, LEN);
close(fd);
if (umount("/root/test1/") < 0) {
perror("cannot umount\n");
exit(1);
}
if (mount("/dev/sda1", "/root/test1/", "ext3", 0, 0) < 0) {
perror("cannot mount\n");
exit(1);
}
fd = open("/root/test1/testfile", O_RDWR);
if (fd < 0) {
perror("cannot open file\n");
exit(1);
}filesize = LEN * LOOP;
for (i = 0; i < 300000; i++){
offset = (random() % filesize) & (~(LEN - 1));
pwrite(fd, buf, LEN, offset);
}
printf("start test\n");
time(&t1);
for (i = 0; i < 100000; i++){
offset = (random() % filesize) & (~(LEN - 1));
pread(fd, buf, LEN, offset);
}
time(&t2);
printf("%ld sec\n", t2-t1);
close(fd);
if (umount("/root/test1/") < 0) {
perror("cannot umount\n");
exit(1);
}
}Signed-off-by: Hisashi Hifumi
Cc: Nick Piggin
Cc: Christoph Hellwig
Cc: Jan Kara
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch fixes the following build error on sh caused by commit
aa888a74977a8f2120ae9332376e179c39a6b07d ("hugetlb: support larger than
MAX_ORDER"):mm/hugetlb.c: In function 'alloc_bootmem_huge_page':
mm/hugetlb.c:958: error: implicit declaration of function 'virt_to_phys'Signed-off-by: Adrian Bunk
Cc: Hirokazu Takata
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
With KVM/GFP/XPMEM there isn't just the primary CPU MMU pointing to pages.
There are secondary MMUs (with secondary sptes and secondary tlbs) too.
sptes in the kvm case are shadow pagetables, but when I say spte in
mmu-notifier context, I mean "secondary pte". In GRU case there's no
actual secondary pte and there's only a secondary tlb because the GRU
secondary MMU has no knowledge about sptes and every secondary tlb miss
event in the MMU always generates a page fault that has to be resolved by
the CPU (this is not the case of KVM where the a secondary tlb miss will
walk sptes in hardware and it will refill the secondary tlb transparently
to software if the corresponding spte is present). The same way
zap_page_range has to invalidate the pte before freeing the page, the spte
(and secondary tlb) must also be invalidated before any page is freed and
reused.Currently we take a page_count pin on every page mapped by sptes, but that
means the pages can't be swapped whenever they're mapped by any spte
because they're part of the guest working set. Furthermore a spte unmap
event can immediately lead to a page to be freed when the pin is released
(so requiring the same complex and relatively slow tlb_gather smp safe
logic we have in zap_page_range and that can be avoided completely if the
spte unmap event doesn't require an unpin of the page previously mapped in
the secondary MMU).The mmu notifiers allow kvm/GRU/XPMEM to attach to the tsk->mm and know
when the VM is swapping or freeing or doing anything on the primary MMU so
that the secondary MMU code can drop sptes before the pages are freed,
avoiding all page pinning and allowing 100% reliable swapping of guest
physical address space. Furthermore it avoids the code that teardown the
mappings of the secondary MMU, to implement a logic like tlb_gather in
zap_page_range that would require many IPI to flush other cpu tlbs, for
each fixed number of spte unmapped.To make an example: if what happens on the primary MMU is a protection
downgrade (from writeable to wrprotect) the secondary MMU mappings will be
invalidated, and the next secondary-mmu-page-fault will call
get_user_pages and trigger a do_wp_page through get_user_pages if it
called get_user_pages with write=1, and it'll re-establishing an updated
spte or secondary-tlb-mapping on the copied page. Or it will setup a
readonly spte or readonly tlb mapping if it's a guest-read, if it calls
get_user_pages with write=0. This is just an example.This allows to map any page pointed by any pte (and in turn visible in the
primary CPU MMU), into a secondary MMU (be it a pure tlb like GRU, or an
full MMU with both sptes and secondary-tlb like the shadow-pagetable layer
with kvm), or a remote DMA in software like XPMEM (hence needing of
schedule in XPMEM code to send the invalidate to the remote node, while no
need to schedule in kvm/gru as it's an immediate event like invalidating
primary-mmu pte).At least for KVM without this patch it's impossible to swap guests
reliably. And having this feature and removing the page pin allows
several other optimizations that simplify life considerably.Dependencies:
1) mm_take_all_locks() to register the mmu notifier when the whole VM
isn't doing anything with "mm". This allows mmu notifier users to keep
track if the VM is in the middle of the invalidate_range_begin/end
critical section with an atomic counter incraese in range_begin and
decreased in range_end. No secondary MMU page fault is allowed to map
any spte or secondary tlb reference, while the VM is in the middle of
range_begin/end as any page returned by get_user_pages in that critical
section could later immediately be freed without any further
->invalidate_page notification (invalidate_range_begin/end works on
ranges and ->invalidate_page isn't called immediately before freeing
the page). To stop all page freeing and pagetable overwrites the
mmap_sem must be taken in write mode and all other anon_vma/i_mmap
locks must be taken too.2) It'd be a waste to add branches in the VM if nobody could possibly
run KVM/GRU/XPMEM on the kernel, so mmu notifiers will only enabled if
CONFIG_KVM=m/y. In the current kernel kvm won't yet take advantage of
mmu notifiers, but this already allows to compile a KVM external module
against a kernel with mmu notifiers enabled and from the next pull from
kvm.git we'll start using them. And GRU/XPMEM will also be able to
continue the development by enabling KVM=m in their config, until they
submit all GRU/XPMEM GPLv2 code to the mainline kernel. Then they can
also enable MMU_NOTIFIERS in the same way KVM does it (even if KVM=n).
This guarantees nobody selects MMU_NOTIFIER=y if KVM and GRU and XPMEM
are all =n.The mmu_notifier_register call can fail because mm_take_all_locks may be
interrupted by a signal and return -EINTR. Because mmu_notifier_reigster
is used when a driver startup, a failure can be gracefully handled. Here
an example of the change applied to kvm to register the mmu notifiers.
Usually when a driver startups other allocations are required anyway and
-ENOMEM failure paths exists already.struct kvm *kvm_arch_create_vm(void)
{
struct kvm *kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL);
+ int err;if (!kvm)
return ERR_PTR(-ENOMEM);INIT_LIST_HEAD(&kvm->arch.active_mmu_pages);
+ kvm->arch.mmu_notifier.ops = &kvm_mmu_notifier_ops;
+ err = mmu_notifier_register(&kvm->arch.mmu_notifier, current->mm);
+ if (err) {
+ kfree(kvm);
+ return ERR_PTR(err);
+ }
+
return kvm;
}mmu_notifier_unregister returns void and it's reliable.
The patch also adds a few needed but missing includes that would prevent
kernel to compile after these changes on non-x86 archs (x86 didn't need
them by luck).[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix mm/filemap_xip.c build]
[akpm@linux-foundation.org: fix mm/mmu_notifier.c build]
Signed-off-by: Andrea Arcangeli
Signed-off-by: Nick Piggin
Signed-off-by: Christoph Lameter
Cc: Jack Steiner
Cc: Robin Holt
Cc: Nick Piggin
Cc: Peter Zijlstra
Cc: Kanoj Sarcar
Cc: Roland Dreier
Cc: Steve Wise
Cc: Avi Kivity
Cc: Hugh Dickins
Cc: Rusty Russell
Cc: Anthony Liguori
Cc: Chris Wright
Cc: Marcelo Tosatti
Cc: Eric Dumazet
Cc: "Paul E. McKenney"
Cc: Izik Eidus
Cc: Anthony Liguori
Cc: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
mm_take_all_locks holds off reclaim from an entire mm_struct. This allows
mmu notifiers to register into the mm at any time with the guarantee that
no mmu operation is in progress on the mm.This operation locks against the VM for all pte/vma/mm related operations
that could ever happen on a certain mm. This includes vmtruncate,
try_to_unmap, and all page faults.The caller must take the mmap_sem in write mode before calling
mm_take_all_locks(). The caller isn't allowed to release the mmap_sem
until mm_drop_all_locks() returns.mmap_sem in write mode is required in order to block all operations that
could modify pagetables and free pages without need of altering the vma
layout (for example populate_range() with nonlinear vmas). It's also
needed in write mode to avoid new anon_vmas to be associated with existing
vmas.A single task can't take more than one mm_take_all_locks() in a row or it
would deadlock.mm_take_all_locks() and mm_drop_all_locks are expensive operations that
may have to take thousand of locks.mm_take_all_locks() can fail if it's interrupted by signals.
When mmu_notifier_register returns, we must be sure that the driver is
notified if some task is in the middle of a vmtruncate for the 'mm' where
the mmu notifier was registered (mmu_notifier_invalidate_range_start/end
is run around the vmtruncation but mmu_notifier_register can run after
mmu_notifier_invalidate_range_start and before
mmu_notifier_invalidate_range_end). Same problem for rmap paths. And
we've to remove page pinning to avoid replicating the tlb_gather logic
inside KVM (and GRU doesn't work well with page pinning regardless of
needing tlb_gather), so without mm_take_all_locks when vmtruncate frees
the page, kvm would have no way to notice that it mapped into sptes a page
that is going into the freelist without a chance of any further
mmu_notifier notification.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Andrea Arcangeli
Acked-by: Linus Torvalds
Cc: Christoph Lameter
Cc: Jack Steiner
Cc: Robin Holt
Cc: Nick Piggin
Cc: Peter Zijlstra
Cc: Kanoj Sarcar
Cc: Roland Dreier
Cc: Steve Wise
Cc: Avi Kivity
Cc: Hugh Dickins
Cc: Rusty Russell
Cc: Anthony Liguori
Cc: Chris Wright
Cc: Marcelo Tosatti
Cc: Eric Dumazet
Cc: "Paul E. McKenney"
Cc: Izik Eidus
Cc: Anthony Liguori
Cc: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
SuSE's insserve initscript ordering program hits kernel BUG at mm/shmem.c:814
on 2.6.26. It's using posix_fadvise on directories, and the shmem_readpage
method added in 2.6.23 is letting POSIX_FADV_WILLNEED allocate useless pages
to a tmpfs directory, incrementing i_blocks count but never decrementing it.Fix this by assigning shmem_aops (pointing to readpage and writepage and
set_page_dirty) only when it's needed, on a regular file or a long symlink.Many thanks to Kel for outstanding bugreport and steps to reproduce it.
Reported-by: Kel Modderman
Tested-by: Kel Modderman
Signed-off-by: Hugh Dickins
Cc: [2.6.25.x, 2.6.26.x]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
28 Jul, 2008
1 commit
-
Signed-off-by: Rusty Russell
27 Jul, 2008
21 commits
-
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (39 commits)
[PATCH] fix RLIM_NOFILE handling
[PATCH] get rid of corner case in dup3() entirely
[PATCH] remove remaining namei_{32,64}.h crap
[PATCH] get rid of indirect users of namei.h
[PATCH] get rid of __user_path_lookup_open
[PATCH] f_count may wrap around
[PATCH] dup3 fix
[PATCH] don't pass nameidata to __ncp_lookup_validate()
[PATCH] don't pass nameidata to gfs2_lookupi()
[PATCH] new (local) helper: user_path_parent()
[PATCH] sanitize __user_walk_fd() et.al.
[PATCH] preparation to __user_walk_fd cleanup
[PATCH] kill nameidata passing to permission(), rename to inode_permission()
[PATCH] take noexec checks to very few callers that care
Re: [PATCH 3/6] vfs: open_exec cleanup
[patch 4/4] vfs: immutable inode checking cleanup
[patch 3/4] fat: dont call notify_change
[patch 2/4] vfs: utimes cleanup
[patch 1/4] vfs: utimes: move owner check into inode_change_ok()
[PATCH] vfs: use kstrdup() and check failing allocation
... -
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
netns: fix ip_rt_frag_needed rt_is_expired
netfilter: nf_conntrack_extend: avoid unnecessary "ct->ext" dereferences
netfilter: fix double-free and use-after free
netfilter: arptables in netns for real
netfilter: ip{,6}tables_security: fix future section mismatch
selinux: use nf_register_hooks()
netfilter: ebtables: use nf_register_hooks()
Revert "pkt_sched: sch_sfq: dump a real number of flows"
qeth: use dev->ml_priv instead of dev->priv
syncookies: Make sure ECN is disabled
net: drop unused BUG_TRAP()
net: convert BUG_TRAP to generic WARN_ON
drivers/net: convert BUG_TRAP to generic WARN_ON -
mm/util.c: In function 'arch_pick_mmap_layout':
mm/util.c:144: error: dereferencing pointer to incomplete type
mm/util.c:145: error: 'arch_get_unmapped_area' undeclared (first use in this function)
mm/util.c:145: error: (Each undeclared identifier is reported only once
mm/util.c:145: error: for each function it appears in.)
mm/util.c:146: error: 'arch_unmap_area' undeclared (first use in this function)Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
All calls to remove_suid() are made with a file pointer, because
(similarly to file_update_time) it is called when the file is written.Clean up callers by passing in a file instead of a dentry.
Signed-off-by: Miklos Szeredi
-
* kill nameidata * argument; map the 3 bits in ->flags anybody cares
about to new MAY_... ones and pass with the mask.
* kill redundant gfs2_iop_permission()
* sanitize ecryptfs_permission()
* fix remaining places where ->permission() instances might barf on new
MAY_... found in mask.The obvious next target in that direction is permission(9)
folded fix for nfs_permission() breakage from Miklos Szeredi
Signed-off-by: Al Viro
-
As suggested by Patrick McHardy, introduce a __krealloc() that doesn't
free the original buffer to fix a double-free and use-after-free bug
introduced by me in netfilter that uses RCU.Reported-by: Patrick McHardy
Signed-off-by: Pekka Enberg
Tested-by: Dieter Ries
Signed-off-by: Patrick McHardy
Signed-off-by: David S. Miller -
This patch makes the following needlessly global code static:
- swap_lock
- nr_swapfiles
- struct swap_listSigned-off-by: Adrian Bunk
Reviewed-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch makes the needlessly global print_bad_pte() static.
Signed-off-by: Adrian Bunk
Reviewed-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch makes the following needlessly global functions static:
- percpu_depopulate()
- __percpu_depopulate_mask()
- percpu_populate()
- __percpu_populate_mask()Signed-off-by: Adrian Bunk
Acked-by: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch makes the needlessly global sparse_early_mem_map_alloc()
static.Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Every arch implements its own show_mem() function. Most of them share
quite some code, some of them are completely identical.This series implements a generic version of this function and migrates
almost all architectures to it.This patch:
Most show_mem() implementations calculate the amount of pages within
the swapcache every time. Move the output to a more appropriate place
and use the anyway available total_swapcache_pages variable.Signed-off-by: Johannes Weiner
Cc: Richard Henderson
Cc: Ivan Kokshaysky
Cc: Haavard Skinnemoen
Cc: Bryan Wu
Cc: Chris Zankel
Cc: Ingo Molnar
Cc: Jeff Dike
Cc: David S. Miller
Cc: Paul Mundt
Cc: Heiko Carstens
Cc: Martin Schwidefsky
Cc: David Howells
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: Yoshinori Sato
Cc: Ralf Baechle
Cc: Greg Ungerer
Cc: Geert Uytterhoeven
Cc: Roman Zippel
Cc: Hirokazu Takata
Cc: Mikael Starvik
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This adds tracehook_expect_breakpoints() as a formal hook for the nommu
code to use for its, "Is text-poking likely?" check at mmap time. This
names the actual semantics the code means to test, and documents it.Signed-off-by: Roland McGrath
Cc: Oleg Nesterov
Reviewed-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Use WARN() instead of a printk+WARN_ON() pair; this way the message becomes
part of the warning section for better reporting/collection.Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Kmem cache passed to constructor is only needed for constructors that are
themselves multiplexeres. Nobody uses this "feature", nor does anybody uses
passed kmem cache in non-trivial way, so pass only pointer to object.Non-trivial places are:
arch/powerpc/mm/init_64.c
arch/powerpc/mm/hugetlbpage.cThis is flag day, yes.
Signed-off-by: Alexey Dobriyan
Acked-by: Pekka Enberg
Acked-by: Christoph Lameter
Cc: Jon Tollefson
Cc: Nick Piggin
Cc: Matt Mackall
[akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c]
[akpm@linux-foundation.org: fix mm/slab.c]
[akpm@linux-foundation.org: fix ubifs]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
mapping->tree_lock has no read lockers. convert the lock from an rwlock
to a spinlock.Signed-off-by: Nick Piggin
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: Hugh Dickins
Cc: "Paul E. McKenney"
Reviewed-by: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Combine page_cache_get_speculative with lockless radix tree lookups to
introduce lockless page cache lookups (ie. no mapping->tree_lock on the
read-side).The only atomicity changes this introduces is that the gang pagecache
lookup functions now behave as if they are implemented with multiple
find_get_page calls, rather than operating on a snapshot of the pages. In
practice, this atomicity guarantee is not used anyway, and it is to
replace individual lookups, so these semantics are natural.Signed-off-by: Nick Piggin
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: Hugh Dickins
Cc: "Paul E. McKenney"
Reviewed-by: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If we can be sure that elevating the page_count on a pagecache page will
pin it, we can speculatively run this operation, and subsequently check to
see if we hit the right page rather than relying on holding a lock or
otherwise pinning a reference to the page.This can be done if get_page/put_page behaves consistently throughout the
whole tree (ie. if we "get" the page after it has been used for something
else, we must be able to free it with a put_page).Actually, there is a period where the count behaves differently: when the
page is free or if it is a constituent page of a compound page. We need
an atomic_inc_not_zero operation to ensure we don't try to grab the page
in either case.This patch introduces the core locking protocol to the pagecache (ie.
adds page_cache_get_speculative, and tweaks some update-side code to make
it work).Thanks to Hugh for pointing out an improvement to the algorithm setting
page_count to zero when we have control of all references, in order to
hold off speculative getters.[kamezawa.hiroyu@jp.fujitsu.com: fix migration_entry_wait()]
[hugh@veritas.com: fix add_to_page_cache]
[akpm@linux-foundation.org: repair a comment]
Signed-off-by: Nick Piggin
Cc: Jeff Garzik
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: Hugh Dickins
Cc: "Paul E. McKenney"
Reviewed-by: Peter Zijlstra
Signed-off-by: Daisuke Nishimura
Signed-off-by: KAMEZAWA Hiroyuki
Signed-off-by: KOSAKI Motohiro
Signed-off-by: Hugh Dickins
Acked-by: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
radix_tree_next_hole() is implemented as a series of radix_tree_lookup()s.
So it can be called locklessly, under rcu_read_lock().Signed-off-by: Nick Piggin
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: Hugh Dickins
Cc: "Paul E. McKenney"
Reviewed-by: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Implement get_user_pages_fast without locking in the fastpath on x86.
Do an optimistic lockless pagetable walk, without taking mmap_sem or any
page table locks or even mmap_sem. Page table existence is guaranteed by
turning interrupts off (combined with the fact that we're always looking
up the current mm, means we can do the lockless page table walk within the
constraints of the TLB shootdown design). Basically we can do this
lockless pagetable walk in a similar manner to the way the CPU's pagetable
walker does not have to take any locks to find present ptes.This patch (combined with the subsequent ones to convert direct IO to use
it) was found to give about 10% performance improvement on a 2 socket 8
core Intel Xeon system running an OLTP workload on DB2 v9.5"To test the effects of the patch, an OLTP workload was run on an IBM
x3850 M2 server with 2 processors (quad-core Intel Xeon processors at
2.93 GHz) using IBM DB2 v9.5 running Linux 2.6.24rc7 kernel. Comparing
runs with and without the patch resulted in an overall performance
benefit of ~9.8%. Correspondingly, oprofiles showed that samples from
__up_read and __down_read routines that is seen during thread contention
for system resources was reduced from 2.8% down to .05%. Monitoring the
/proc/vmstat output from the patched run showed that the counter for
fast_gup contained a very high number while the fast_gup_slow value was
zero."(fast_gup is the old name for get_user_pages_fast, fast_gup_slow is a
counter we had for the number of times the slowpath was invoked).The main reason for the improvement is that DB2 has multiple threads each
issuing direct-IO. Direct-IO uses get_user_pages, and thus the threads
contend the mmap_sem cacheline, and can also contend on page table locks.I would anticipate larger performance gains on larger systems, however I
think DB2 uses an adaptive mix of threads and processes, so it could be
that thread contention remains pretty constant as machine size increases.
In which case, we stuck with "only" a 10% gain.The downside of using get_user_pages_fast is that if there is not a pte
with the correct permissions for the access, we end up falling back to
get_user_pages and so the get_user_pages_fast is a bit of extra work.
However this should not be the common case in most performance critical
code.[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: Kconfig fix]
[akpm@linux-foundation.org: Makefile fix/cleanup]
[akpm@linux-foundation.org: warning fix]
Signed-off-by: Nick Piggin
Cc: Dave Kleikamp
Cc: Andy Whitcroft
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: Andi Kleen
Cc: Dave Kleikamp
Cc: Badari Pulavarty
Cc: Zach Brown
Cc: Jens Axboe
Reviewed-by: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fixes a build failure reported by Alan Cox:
mm/hugetlb.c: In function `hugetlb_acct_memory': mm/hugetlb.c:1507:
error: implicit declaration of function `cpuset_mems_nr'Also reverts Ingo's
commit e44d1b2998d62a1f2f4d7eb17b56ba396535509f
Author: Ingo Molnar
Date: Fri Jul 25 12:57:41 2008 +0200mm/hugetlb.c: fix build failure with !CONFIG_SYSCTL
which fixed the build error but added some unused-static-function warnings.
Signed-off-by: Nishanth Aravamudan
Cc: Alan Cox
Cc: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix this, on avr32:
include/linux/utsname.h:35,
from init/main.c:20:
include/linux/sched.h: In function 'arch_pick_mmap_layout':
include/linux/sched.h:2149: error: implicit declaration of function 'PAGE_ALIGN'Reported-by: Adrian Bunk
Cc: Haavard Skinnemoen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
26 Jul, 2008
1 commit
-
on !CONFIG_SYSCTL on x86 with latest -git i get:
mm/hugetlb.c: In function 'decrement_hugepage_resv_vma':
mm/hugetlb.c:83: error: 'reserve' undeclared (first use in this function)
mm/hugetlb.c:83: error: (Each undeclared identifier is reported only once
mm/hugetlb.c:83: error: for each function it appears in.)Signed-off-by: Ingo Molnar
Signed-off-by: Linus Torvalds
