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2008-08-23pcmcia: pcmcia_config_loop() improvement by passing vccDominik Brodowski
By passing the current Vcc setting to the pcmcia_config_loop callback function, we can remove pcmcia_get_configuration_info() calls from many drivers. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2008-08-23pcmcia: pcmcia_config_loop() default CIS entry handlingDominik Brodowski
Many drivers use the default CIS entry within their pcmcia_config_loop() callback function. Therefore, factor the default CIS entry handling out. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2008-08-23pcmcia: pcmcia_config_loop() ConfigIndex unificationDominik Brodowski
Almost all drivers set p_dev->conf.ConfigIndex to cfg->index in the pcmcia_config_loop() callback function. Therefore, factor it out. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2008-08-23pcmcia: use pcmcia_loop_config in misc pcmcia driversDominik Brodowski
Use the config loop helper in misc pcmcia drivers. CC: Harald Welte <laforge@gnumonks.org> CC: <linux-parport@lists.infradead.org> CC: Russell King <rmk+kernel@arm.linux.org.uk> CC: Ed Okerson <eokerson@quicknet.net> CC: linux-serial@vger.kernel.org CC: boti@rocketmail.com CC: linux-usb@vger.kernel.org Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2008-08-23pcmcia: use pcmcia_loop_config in net pcmcia driversDominik Brodowski
Use the config loop helper in (some) net pcmcia drivers. CC: netdev@vger.kernel.org Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2008-08-23pcmcia: use pcmcia_loop_config in ISDN pcmcia driversDominik Brodowski
Use the config loop helper in ISDN pcmcia drivers. CC: Karsten Keil <kkeil@suse.de> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2008-08-23pcmcia: use pcmcia_loop_config in scsi pcmcia driversDominik Brodowski
Use the config loop helper in scsi pcmcia drivers. CC: James E.J. Bottomley <James.Bottomley@HansenPartnership.com> CC: linux-scsi@vger.kernel.org Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2008-08-23pcmcia: use pcmcia_loop_config in bluetooth driversDominik Brodowski
Use the config loop helper in bluetooth pcmcia drivers. CC: Marcel Holtmann <marcel@holtmann.org> CC: linux-bluetooth@vger.kernel.org Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2008-08-23pcmcia: use pcmcia_loop_config in pata and ide driversDominik Brodowski
Use the config loop helper in pata_pcmcia and ide_cs CC: Tejun Heo <htejun@gmail.com> CC: Alan Cox <alan@lxorguk.ukuu.org.uk> CC: linux-ide@vger.kernel.org Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2008-08-23pcmcia: add pcmcia_loop_config() helperDominik Brodowski
By calling pcmcia_loop_config(), a pcmcia driver can iterate over all available configuration options. During a driver's probe() phase, one doesn't need to use pcmcia_get_{first,next}_tuple, pcmcia_get_tuple_data and pcmcia_parse_tuple directly in most if not all cases. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2008-07-28Linux 2.6.27-rc1Linus Torvalds
2008-07-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linusLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: lguest: turn Waker into a thread, not a process lguest: Enlarge virtio rings lguest: Use GSO/IFF_VNET_HDR extensions on tun/tap lguest: Remove 'network: no dma buffer!' warning lguest: Adaptive timeout lguest: Tell Guest net not to notify us on every packet xmit lguest: net block unneeded receive queue update notifications lguest: wrap last_avail accesses. lguest: use cpu capability accessors lguest: virtio-rng support lguest: Support assigning a MAC address lguest: Don't leak /dev/zero fd lguest: fix verbose printing of device features. lguest: fix switcher_page leak on unload lguest: Guest int3 fix lguest: set max_pfn_mapped, growl loudly at Yinghai Lu
2008-07-28Merge branch 'for-linus' of git://git.o-hand.com/linux-mfdLinus Torvalds
* 'for-linus' of git://git.o-hand.com/linux-mfd: mfd: accept pure device as a parent, not only platform_device mfd: add platform_data to mfd_cell mfd: Coding style fixes mfd: Use to_platform_device instead of container_of
2008-07-28Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (21 commits) x86/PCI: use dev_printk when possible PCI: add D3 power state avoidance quirk PCI: fix bogus "'device' may be used uninitialized" warning in pci_slot PCI: add an option to allow ASPM enabled forcibly PCI: disable ASPM on pre-1.1 PCIe devices PCI: disable ASPM per ACPI FADT setting PCI MSI: Don't disable MSIs if the mask bit isn't supported PCI: handle 64-bit resources better on 32-bit machines PCI: rewrite PCI BAR reading code PCI: document pci_target_state PCI hotplug: fix typo in pcie hotplug output x86 gart: replace to_pages macro with iommu_num_pages x86, AMD IOMMU: replace to_pages macro with iommu_num_pages iommu: add iommu_num_pages helper function dma-coherent: add documentation to new interfaces Cris: convert to using generic dma-coherent mem allocator Sh: use generic per-device coherent dma allocator ARM: support generic per-device coherent dma mem Generic dma-coherent: fix DMA_MEMORY_EXCLUSIVE x86: use generic per-device dma coherent allocator ...
2008-07-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6: [SCSI] qla2xxx: fix msleep compile error
2008-07-28Fix 'get_user_pages_fast()' with non-page-aligned start addressLinus Torvalds
Alexey Dobriyan reported trouble with LTP with the new fast-gup code, and Johannes Weiner debugged it to non-page-aligned addresses, where the new get_user_pages_fast() code would do all the wrong things, including just traversing past the end of the requested area due to 'addr' never matching 'end' exactly. This is not a pretty fix, and we may actually want to move the alignment into generic code, leaving just the core code per-arch, but Alexey verified that the vmsplice01 LTP test doesn't crash with this. Reported-and-tested-by: Alexey Dobriyan <adobriyan@gmail.com> Debugged-by: Johannes Weiner <hannes@saeurebad.de> Cc: Nick Piggin <npiggin@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-29lguest: turn Waker into a thread, not a processRusty Russell
lguest uses a Waker process to break it out of the kernel (ie. actually running the guest) when file descriptor needs attention. Changing this from a process to a thread somewhat simplifies things: it can directly access the fd_set of things to watch. More importantly, it means that the Waker can see Guest memory correctly, so /dev/vring file descriptors will work as anticipated (the alternative is to actually mmap MAP_SHARED, but you can't do that with /dev/zero). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29lguest: Enlarge virtio ringsRusty Russell
With big packets, 128 entries is a little small. Guest -> Host 1GB TCP: Before: 8.43625 seconds xmit 95640 recv 198266 timeout 49771 usec 1252 After: 8.01099 seconds xmit 49200 recv 102263 timeout 26014 usec 2118 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29lguest: Use GSO/IFF_VNET_HDR extensions on tun/tapRusty Russell
Guest -> Host 1GB TCP: Before 20.1974 seconds xmit 214510 recv 5 timeout 214491 usec 278 After 8.43625 seconds xmit 95640 recv 198266 timeout 49771 usec 1252 Host -> Guest 1GB TCP: Before: Seconds 9.98854 xmit 172166 recv 5344 timeout 172157 usec 251 After: Seconds 5.72803 xmit 244322 recv 9919 timeout 244302 usec 156 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29lguest: Remove 'network: no dma buffer!' warningRusty Russell
This warning can happen a lot under load, and it should be warnx not warn anwyay. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29lguest: Adaptive timeoutRusty Russell
Since the correct timeout value varies, use a heuristic which adjusts the timeout depending on how many packets we've seen. This gives slightly worse results, but doesn't need tweaking when GSO is introduced. 500 usec 19.1887 xmit 561141 recv 1 timeout 559657 Dynamic (278) 20.1974 xmit 214510 recv 5 timeout 214491 usec 278 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29lguest: Tell Guest net not to notify us on every packet xmitRusty Russell
virtio_ring has the ability to suppress notifications. This prevents a guest exit for every packet, but we need to set a timer on packet receipt to re-check if there were any remaining packets. Here are the times for 1G TCP Guest->Host with different timeout settings (it matters because the TCP window doesn't grow big enough to fill the entire buffer): Timeout value Seconds Xmit/Recv/Timeout None (before) 25.3784 xmit 7750233 recv 1 2500 usec 62.5119 xmit 207020 recv 2 timeout 207020 1000 usec 34.5379 xmit 207003 recv 2 timeout 207003 750 usec 29.2305 xmit 207002 recv 1 timeout 207002 500 usec 19.1887 xmit 561141 recv 1 timeout 559657 250 usec 20.0465 xmit 214128 recv 2 timeout 214110 100 usec 19.2583 xmit 561621 recv 1 timeout 560153 (Note that these values are sensitive to the GSO patches which come later, and probably other traffic-related variables, so take with a large grain of salt). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29lguest: net block unneeded receive queue update notificationsRusty Russell
Number of exits transmitting 10GB Guest->Host before: network xmit 7858610 recv 118136 After: network xmit 7750233 recv 1 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29lguest: wrap last_avail accesses.Rusty Russell
To simplify the transition to when we publish indices in the ring (and make shuffling my patch queue easier), wrap them in a lg_last_avail() macro. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29lguest: use cpu capability accessorsAndrew Morton
To support my little make-x86-bitops-use-proper-typechecking projectlet. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrea Arcangeli <andrea@qumranet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29lguest: virtio-rng supportRusty Russell
This is a simple patch to add support for the virtio "hardware random generator" to lguest. It gets about 1.2 MB/sec reading from /dev/hwrng in the guest. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29lguest: Support assigning a MAC addressMark McLoughlin
If you've got a nice DHCP configuration which maps MAC addresses to specific IP addresses, then you're going to want to start your guest with one of those MAC addresses. Also, in Fedora, we have persistent network interface naming based on the MAC address, so with randomly assigned addresses you're soon going to hit eth13. Who knows what will happen then! Allow assigning a MAC address to the network interface with e.g. --tunnet=bridge:eth0:00:FF:95:6B:DA:3D or: --tunnet=192.168.121.1:00:FF:95:6B:DA:3D which is pretty unintelligable, but ... (includes Rusty's minor rework) Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29lguest: Don't leak /dev/zero fdMark McLoughlin
Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29lguest: fix verbose printing of device features.Rusty Russell
%02x is more appropriate for bytes than %08x. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29lguest: fix switcher_page leak on unloadJohannes Weiner
map_switcher allocates the array, unmap_switcher has to free it accordingly. Signed-off-by: Johannes Weiner <hannes@saeurebad.de> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29lguest: Guest int3 fixRusty Russell
Ron Minnich noticed that guest userspace gets a GPF when it tries to int3: we need to copy the privilege level from the guest-supplied IDT to the real IDT. int3 is the only common case where guest userspace expects to invoke an interrupt, so that's the symptom of failing to do this. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29lguest: set max_pfn_mapped, growl loudly at Yinghai LuRusty Russell
6af61a7614a306fe882a0c2b4ddc63b65aa66efc 'x86: clean up max_pfn_mapped usage - 32-bit' makes the following comment: XEN PV and lguest may need to assign max_pfn_mapped too. But no CC. Yinghai, wasting fellow developers' time is a VERY bad habit. If you do it again, I will hunt you down and try to extract the three hours of my life I just lost :) Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Yinghai Lu <yhlu.kernel@gmail.com>
2008-07-29mfd: accept pure device as a parent, not only platform_deviceDmitry Baryshkov
Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com> Signed-off-by: Samuel Ortiz <sameo@openedhand.com>
2008-07-28include/asm-generic/pgtable-nopmd.h: macros are noxious, reason #435Andrew Morton
arch/x86/mm/pgtable.c: In function 'pgd_mop_up_pmds': arch/x86/mm/pgtable.c:194: warning: unused variable 'pmd' Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28sh7760fb: write colormap value to hardwareManuel Lauss
The computed color value is never actually written to hardware colormap register. Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net> Cc: Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com> Cc: Munakata Hisao <munakata.hisao@renesas.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28eCryptfs: use page_alloc not kmalloc to get a page of memoryEric Sandeen
With SLUB debugging turned on in 2.6.26, I was getting memory corruption when testing eCryptfs. The root cause turned out to be that eCryptfs was doing kmalloc(PAGE_CACHE_SIZE); virt_to_page() and treating that as a nice page-aligned chunk of memory. But at least with SLUB debugging on, this is not always true, and the page we get from virt_to_page does not necessarily match the PAGE_CACHE_SIZE worth of memory we got from kmalloc. My simple testcase was 2 loops doing "rm -f fileX; cp /tmp/fileX ." for 2 different multi-megabyte files. With this change I no longer see the corruption. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Acked-by: Michael Halcrow <mhalcrow@us.ibm.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28gpio: fix build on CONFIG_GPIO_SYSFS=nAtsushi Nemoto
If CONFIG_GENERIC_GPIO=y && CONFIG_GPIO_SYSFS=n, gpio_export() in asm-generic/gpio.h refers -ENOSYS and causes build error. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28bio-integrity: remove EXPORT_SYMBOL for bio_integrity_init_slab()Yoichi Yuasa
I got section mismatch message about bio_integrity_init_slab(). WARNING: fs/built-in.o(__ksymtab+0xb60): Section mismatch in reference from the variable __ksymtab_bio_integrity_init_slab to the function .init.text:bio_integrity_init_slab() The symbol bio_integrity_init_slab is exported and annotated __init Fix this by removing the __init annotation of bio_integrity_init_slab or drop the export. It only call from init_bio(). The EXPORT_SYMBOL() can be removed. Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28vfs: pagecache usage optimization for pagesize!=blocksizeHisashi Hifumi
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 sec 2.6.26-patched 226 sec Arch:i386 Filesystem:ext3 Blocksize:1024 bytes Memory: 1GB On 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 <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> #include <time.h> #include <stdlib.h> #include <string.h> #include <sys/mount.h> #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 <hifumi.hisashi@oss.ntt.co.jp> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Christoph Hellwig <hch@infradead.org> Cc: Jan Kara <jack@ucw.cz> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28kdump: update kdump documentation as kexec-tools-resting has been renamed ↵Simon Horman
kexec-tools Signed-off-by: Simon Horman <horms@verge.net.au> Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28spi_s3c24xx: really assign busnumBen Dooks
The original "Pass the bus number we expect the S3C24XX SPI driver to attach to via the platform data." [1] patch was mis-sent, and missed two important parts of the diff, which was to actually set the bus_num field and add the relevant field to the platform data. The previous commit 50f426b55d919dd017af35bb6a08753d1f262920 promised to add a bus_num field, but failed to include the two hunks that added this field to include/asm-arm/arch-s3c2410/spi.h and then pass it to the spi core when creating the new master field in drivers/spi/spi_s3c24xx.c. [1] git commit 50f426b55d919dd017af35bb6a08753d1f262920 Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28mpc52xx_psc_spi: fix block transferLuotao Fu
The block transfer routine in the mpc52xx psc spi driver misinterpret the datasheet. According to the processor datasheet the chipselect is held as long as the EOF is not written. Theoretically blocks of any sizes can be transferred in this way. The old routine however writes an EOF after every word, which has the size of size_of_word. This makes the transfer slow. Also fixed some duplicate code. Signed-off-by: Luotao Fu <l.fu@pengutronix.de> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28mm/hugetlb.c must #include <asm/io.h>Adrian Bunk
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 <bunk@kernel.org> Cc: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28mmu-notifiers: coreAndrea Arcangeli
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 <andrea@qumranet.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Cc: Jack Steiner <steiner@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Kanoj Sarcar <kanojsarcar@yahoo.com> Cc: Roland Dreier <rdreier@cisco.com> Cc: Steve Wise <swise@opengridcomputing.com> Cc: Avi Kivity <avi@qumranet.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Anthony Liguori <aliguori@us.ibm.com> Cc: Chris Wright <chrisw@redhat.com> Cc: Marcelo Tosatti <marcelo@kvack.org> Cc: Eric Dumazet <dada1@cosmosbay.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Izik Eidus <izike@qumranet.com> Cc: Anthony Liguori <aliguori@us.ibm.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28mmu-notifiers: add mm_take_all_locks() operationAndrea Arcangeli
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 <andrea@qumranet.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Jack Steiner <steiner@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Kanoj Sarcar <kanojsarcar@yahoo.com> Cc: Roland Dreier <rdreier@cisco.com> Cc: Steve Wise <swise@opengridcomputing.com> Cc: Avi Kivity <avi@qumranet.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Anthony Liguori <aliguori@us.ibm.com> Cc: Chris Wright <chrisw@redhat.com> Cc: Marcelo Tosatti <marcelo@kvack.org> Cc: Eric Dumazet <dada1@cosmosbay.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Izik Eidus <izike@qumranet.com> Cc: Anthony Liguori <aliguori@us.ibm.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28mmu-notifiers: add list_del_init_rcu()Andrea Arcangeli
Introduce list_del_init_rcu() and document it. Signed-off-by: Andrea Arcangeli <andrea@qumranet.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Jack Steiner <steiner@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Kanoj Sarcar <kanojsarcar@yahoo.com> Cc: Roland Dreier <rdreier@cisco.com> Cc: Steve Wise <swise@opengridcomputing.com> Cc: Avi Kivity <avi@qumranet.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Anthony Liguori <aliguori@us.ibm.com> Cc: Chris Wright <chrisw@redhat.com> Cc: Marcelo Tosatti <marcelo@kvack.org> Cc: Eric Dumazet <dada1@cosmosbay.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Izik Eidus <izike@qumranet.com> Cc: Anthony Liguori <aliguori@us.ibm.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28arm: fix HAVE_CLK merge goofDavid Brownell
This fixes a merge goof whereby ARCH_EP93XX got the "select HAVE_CLK" line which belongs instead with ARCH_AT91. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28__ratelimit() cpu flags can't be staticAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28tmpfs: fix kernel BUG in shmem_delete_inodeHugh Dickins
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 <kel@otaku42.de> Tested-by: Kel Modderman <kel@otaku42.de> Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28exec: include pagemap.h again to fix buildHugh Dickins
Fix compilation errors on avr32 and without CONFIG_SWAP, introduced by ba92a43dbaee339cf5915ef766d3d3ffbaaf103c ("exec: remove some includes") In file included from include/asm/tlb.h:24, from fs/exec.c:55: include/asm-generic/tlb.h: In function 'tlb_flush_mmu': include/asm-generic/tlb.h:76: error: implicit declaration of function 'release_pages' include/asm-generic/tlb.h: In function 'tlb_remove_page': include/asm-generic/tlb.h:105: error: implicit declaration of function 'page_cache_release' make[1]: *** [fs/exec.o] Error 1 This straightforward part-revert is nobody's favourite patch to address the underlying tlb.h needs swap.h needs pagemap.h (but sparc won't like that) mess; but appropriate to fix the build now before any overhaul. Reported-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp> Reported-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Tested-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>