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2009-04-01eventfd: improve support for semaphore-like behaviorDavide Libenzi
People started using eventfd in a semaphore-like way where before they were using pipes. That is, counter-based resource access. Where a "wait()" returns immediately by decrementing the counter by one, if counter is greater than zero. Otherwise will wait. And where a "post(count)" will add count to the counter releasing the appropriate amount of waiters. If eventfd the "post" (write) part is fine, while the "wait" (read) does not dequeue 1, but the whole counter value. The problem with eventfd is that a read() on the fd returns and wipes the whole counter, making the use of it as semaphore a little bit more cumbersome. You can do a read() followed by a write() of COUNTER-1, but IMO it's pretty easy and cheap to make this work w/out extra steps. This patch introduces a new eventfd flag that tells eventfd to only dequeue 1 from the counter, allowing simple read/write to make it behave like a semaphore. Simple test here: http://www.xmailserver.org/eventfd-sem.c To be back-compatible with earlier kernels, userspace applications should probe for the availability of this feature via #ifdef EFD_SEMAPHORE fd = eventfd2 (CNT, EFD_SEMAPHORE); if (fd == -1 && errno == EINVAL) <fallback> #else <fallback> #endif Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: <linux-api@vger.kernel.org> Tested-by: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Ulrich Drepper <drepper@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01epoll: use real type instead of void *Tony Battersby
eventpoll.c uses void * in one place for no obvious reason; change it to use the real type instead. Signed-off-by: Tony Battersby <tonyb@cybernetics.com> Acked-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01epoll: clean up ep_modifyTony Battersby
ep_modify() doesn't need to set event.data from within the ep->lock spinlock as the comment suggests. The only place event.data is used is ep_send_events_proc(), and this is protected by ep->mtx instead of ep->lock. Also update the comment for mutex_lock() at the top of ep_scan_ready_list(), which mentions epoll_ctl(EPOLL_CTL_DEL) but not epoll_ctl(EPOLL_CTL_MOD). ep_modify() can also use spin_lock_irq() instead of spin_lock_irqsave(). Signed-off-by: Tony Battersby <tonyb@cybernetics.com> Acked-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01epoll: remove unnecessary xchgTony Battersby
xchg in ep_unregister_pollwait() is unnecessary because it is protected by either epmutex or ep->mtx (the same protection as ep_remove()). If xchg was necessary, it would be insufficient to protect against problems: if multiple concurrent calls to ep_unregister_pollwait() were possible then a second caller that returns without doing anything because nwait == 0 could return before the waitqueues are removed by the first caller, which looks like it could lead to problematic races with ep_poll_callback(). So remove xchg and add comments about the locking. Signed-off-by: Tony Battersby <tonyb@cybernetics.com> Acked-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01epoll: remember the event if epoll_wait returns -EFAULTTony Battersby
If epoll_wait returns -EFAULT, the event that was being returned when the fault was encountered will be forgotten. This is not a big deal since EFAULT will happen only if a buggy userspace program passes in a bad address, in which case what happens later usually doesn't matter. However, it is easy to remember the event for later, and this patch makes a simple change to do that. Signed-off-by: Tony Battersby <tonyb@cybernetics.com> Acked-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01epoll: don't use current in irq contextTony Battersby
ep_call_nested() (formerly ep_poll_safewake()) uses "current" (without dereferencing it) to detect callback recursion, but it may be called from irq context where the use of current is generally discouraged. It would be better to use get_cpu() and put_cpu() to detect the callback recursion. Signed-off-by: Tony Battersby <tonyb@cybernetics.com> Acked-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01epoll: remove debugging codeDavide Libenzi
Remove debugging code from epoll. There's no need for it to be included into mainline code. Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01epoll: fix epoll's own poll (update)Davide Libenzi
Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: Pavel Pisa <pisa@cmp.felk.cvut.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01epoll: fix epoll's own pollDavide Libenzi
Fix a bug inside the epoll's f_op->poll() code, that returns POLLIN even though there are no actual ready monitored fds. The bug shows up if you add an epoll fd inside another fd container (poll, select, epoll). The problem is that callback-based wake ups used by epoll does not carry (patches will follow, to fix this) any information about the events that actually happened. So the callback code, since it can't call the file* ->poll() inside the callback, chains the file* into a ready-list. So, suppose you added an fd with EPOLLOUT only, and some data shows up on the fd, the file* mapped by the fd will be added into the ready-list (via wakeup callback). During normal epoll_wait() use, this condition is sorted out at the time we're actually able to call the file*'s f_op->poll(). Inside the old epoll's f_op->poll() though, only a quick check !list_empty(ready-list) was performed, and this could have led to reporting POLLIN even though no ready fds would show up at a following epoll_wait(). In order to correctly report the ready status for an epoll fd, the ready-list must be checked to see if any really available fd+event would be ready in a following epoll_wait(). Operation (calling f_op->poll() from inside f_op->poll()) that, like wake ups, must be handled with care because of the fact that epoll fds can be added to other epoll fds. Test code: /* * epoll_test by Davide Libenzi (Simple code to test epoll internals) * Copyright (C) 2008 Davide Libenzi * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * Davide Libenzi <davidel@xmailserver.org> * */ #include <sys/types.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <errno.h> #include <signal.h> #include <limits.h> #include <poll.h> #include <sys/epoll.h> #include <sys/wait.h> #define EPWAIT_TIMEO (1 * 1000) #ifndef POLLRDHUP #define POLLRDHUP 0x2000 #endif #define EPOLL_MAX_CHAIN 100L #define EPOLL_TF_LOOP (1 << 0) struct epoll_test_cfg { long size; long flags; }; static int xepoll_create(int n) { int epfd; if ((epfd = epoll_create(n)) == -1) { perror("epoll_create"); exit(2); } return epfd; } static void xepoll_ctl(int epfd, int cmd, int fd, struct epoll_event *evt) { if (epoll_ctl(epfd, cmd, fd, evt) < 0) { perror("epoll_ctl"); exit(3); } } static void xpipe(int *fds) { if (pipe(fds)) { perror("pipe"); exit(4); } } static pid_t xfork(void) { pid_t pid; if ((pid = fork()) == (pid_t) -1) { perror("pipe"); exit(5); } return pid; } static int run_forked_proc(int (*proc)(void *), void *data) { int status; pid_t pid; if ((pid = xfork()) == 0) exit((*proc)(data)); if (waitpid(pid, &status, 0) != pid) { perror("waitpid"); return -1; } return WIFEXITED(status) ? WEXITSTATUS(status): -2; } static int check_events(int fd, int timeo) { struct pollfd pfd; fprintf(stdout, "Checking events for fd %d\n", fd); memset(&pfd, 0, sizeof(pfd)); pfd.fd = fd; pfd.events = POLLIN | POLLOUT; if (poll(&pfd, 1, timeo) < 0) { perror("poll()"); return 0; } if (pfd.revents & POLLIN) fprintf(stdout, "\tPOLLIN\n"); if (pfd.revents & POLLOUT) fprintf(stdout, "\tPOLLOUT\n"); if (pfd.revents & POLLERR) fprintf(stdout, "\tPOLLERR\n"); if (pfd.revents & POLLHUP) fprintf(stdout, "\tPOLLHUP\n"); if (pfd.revents & POLLRDHUP) fprintf(stdout, "\tPOLLRDHUP\n"); return pfd.revents; } static int epoll_test_tty(void *data) { int epfd, ifd = fileno(stdin), res; struct epoll_event evt; if (check_events(ifd, 0) != POLLOUT) { fprintf(stderr, "Something is cooking on STDIN (%d)\n", ifd); return 1; } epfd = xepoll_create(1); fprintf(stdout, "Created epoll fd (%d)\n", epfd); memset(&evt, 0, sizeof(evt)); evt.events = EPOLLIN; xepoll_ctl(epfd, EPOLL_CTL_ADD, ifd, &evt); if (check_events(epfd, 0) & POLLIN) { res = epoll_wait(epfd, &evt, 1, 0); if (res == 0) { fprintf(stderr, "Epoll fd (%d) is ready when it shouldn't!\n", epfd); return 2; } } return 0; } static int epoll_wakeup_chain(void *data) { struct epoll_test_cfg *tcfg = data; int i, res, epfd, bfd, nfd, pfds[2]; pid_t pid; struct epoll_event evt; memset(&evt, 0, sizeof(evt)); evt.events = EPOLLIN; epfd = bfd = xepoll_create(1); for (i = 0; i < tcfg->size; i++) { nfd = xepoll_create(1); xepoll_ctl(bfd, EPOLL_CTL_ADD, nfd, &evt); bfd = nfd; } xpipe(pfds); if (tcfg->flags & EPOLL_TF_LOOP) { xepoll_ctl(bfd, EPOLL_CTL_ADD, epfd, &evt); /* * If we're testing for loop, we want that the wakeup * triggered by the write to the pipe done in the child * process, triggers a fake event. So we add the pipe * read size with EPOLLOUT events. This will trigger * an addition to the ready-list, but no real events * will be there. The the epoll kernel code will proceed * in calling f_op->poll() of the epfd, triggering the * loop we want to test. */ evt.events = EPOLLOUT; } xepoll_ctl(bfd, EPOLL_CTL_ADD, pfds[0], &evt); /* * The pipe write must come after the poll(2) call inside * check_events(). This tests the nested wakeup code in * fs/eventpoll.c:ep_poll_safewake() * By having the check_events() (hence poll(2)) happens first, * we have poll wait queue filled up, and the write(2) in the * child will trigger the wakeup chain. */ if ((pid = xfork()) == 0) { sleep(1); write(pfds[1], "w", 1); exit(0); } res = check_events(epfd, 2000) & POLLIN; if (waitpid(pid, NULL, 0) != pid) { perror("waitpid"); return -1; } return res; } static int epoll_poll_chain(void *data) { struct epoll_test_cfg *tcfg = data; int i, res, epfd, bfd, nfd, pfds[2]; pid_t pid; struct epoll_event evt; memset(&evt, 0, sizeof(evt)); evt.events = EPOLLIN; epfd = bfd = xepoll_create(1); for (i = 0; i < tcfg->size; i++) { nfd = xepoll_create(1); xepoll_ctl(bfd, EPOLL_CTL_ADD, nfd, &evt); bfd = nfd; } xpipe(pfds); if (tcfg->flags & EPOLL_TF_LOOP) { xepoll_ctl(bfd, EPOLL_CTL_ADD, epfd, &evt); /* * If we're testing for loop, we want that the wakeup * triggered by the write to the pipe done in the child * process, triggers a fake event. So we add the pipe * read size with EPOLLOUT events. This will trigger * an addition to the ready-list, but no real events * will be there. The the epoll kernel code will proceed * in calling f_op->poll() of the epfd, triggering the * loop we want to test. */ evt.events = EPOLLOUT; } xepoll_ctl(bfd, EPOLL_CTL_ADD, pfds[0], &evt); /* * The pipe write mush come before the poll(2) call inside * check_events(). This tests the nested f_op->poll calls code in * fs/eventpoll.c:ep_eventpoll_poll() * By having the pipe write(2) happen first, we make the kernel * epoll code to load the ready lists, and the following poll(2) * done inside check_events() will test nested poll code in * ep_eventpoll_poll(). */ if ((pid = xfork()) == 0) { write(pfds[1], "w", 1); exit(0); } sleep(1); res = check_events(epfd, 1000) & POLLIN; if (waitpid(pid, NULL, 0) != pid) { perror("waitpid"); return -1; } return res; } int main(int ac, char **av) { int error; struct epoll_test_cfg tcfg; fprintf(stdout, "\n********** Testing TTY events\n"); error = run_forked_proc(epoll_test_tty, NULL); fprintf(stdout, error == 0 ? "********** OK\n": "********** FAIL (%d)\n", error); tcfg.size = 3; tcfg.flags = 0; fprintf(stdout, "\n********** Testing short wakeup chain\n"); error = run_forked_proc(epoll_wakeup_chain, &tcfg); fprintf(stdout, error == POLLIN ? "********** OK\n": "********** FAIL (%d)\n", error); tcfg.size = EPOLL_MAX_CHAIN; tcfg.flags = 0; fprintf(stdout, "\n********** Testing long wakeup chain (HOLD ON)\n"); error = run_forked_proc(epoll_wakeup_chain, &tcfg); fprintf(stdout, error == 0 ? "********** OK\n": "********** FAIL (%d)\n", error); tcfg.size = 3; tcfg.flags = 0; fprintf(stdout, "\n********** Testing short poll chain\n"); error = run_forked_proc(epoll_poll_chain, &tcfg); fprintf(stdout, error == POLLIN ? "********** OK\n": "********** FAIL (%d)\n", error); tcfg.size = EPOLL_MAX_CHAIN; tcfg.flags = 0; fprintf(stdout, "\n********** Testing long poll chain (HOLD ON)\n"); error = run_forked_proc(epoll_poll_chain, &tcfg); fprintf(stdout, error == 0 ? "********** OK\n": "********** FAIL (%d)\n", error); tcfg.size = 3; tcfg.flags = EPOLL_TF_LOOP; fprintf(stdout, "\n********** Testing loopy wakeup chain (HOLD ON)\n"); error = run_forked_proc(epoll_wakeup_chain, &tcfg); fprintf(stdout, error == 0 ? "********** OK\n": "********** FAIL (%d)\n", error); tcfg.size = 3; tcfg.flags = EPOLL_TF_LOOP; fprintf(stdout, "\n********** Testing loopy poll chain (HOLD ON)\n"); error = run_forked_proc(epoll_poll_chain, &tcfg); fprintf(stdout, error == 0 ? "********** OK\n": "********** FAIL (%d)\n", error); return 0; } Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: Pavel Pisa <pisa@cmp.felk.cvut.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01drivers/misc/isl29003.c: driver for the ISL29003 ambient light sensorDaniel Mack
Add a driver for Intersil's ISL29003 ambient light sensor device plus some documentation. Inspired by tsl2550.c, a driver for a similar device. It is put in drivers/misc for now until the industrial I/O framework gets merged. Signed-off-by: Daniel Mack <daniel@caiaq.de> Acked-by: Jonathan Cameron <jic23@cam.ac.uk> Cc: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01hpilo: reduce frequency of IO operationsDavid Altobelli
Change hpilo open and close logic to spin for 10usec between checking device, rather than every usec. Because the loop is coded to take up to 10ms, it seemed prudent to increase the interval between polling the device, to reduce the load on the system and allow more other work to happen. Signed-off-by: David Altobelli <david.altobelli@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01ntfs: remove private wrapper of endian helpersHarvey Harrison
The base versions handle constant folding now and are shorter than these private wrappers, use them directly. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Cc: Anton Altaparmakov <aia21@cantab.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01introduce pr_cont() macroCyrill Gorcunov
We cover all log-levels by pr_... macros except KERN_CONT one. Add it for convenience. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01init/main.c: fix sparse warnings: context imbalanceHannes Eder
Impact: Attribute function 'init_post' with __releases(...). Fix these sparse warnings: init/main.c:805:21: warning: context imbalance in 'init_post' - unexpected unlock init/main.c:899:9: warning: context imbalance in 'kernel_init' - wrong count at exit Signed-off-by: Hannes Eder <hannes@hanneseder.net> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01bcm47xx: fix GPIO API return codesMichael Buesch
The GPIO API is supposed to return 0 or a negative error code, but the SSB GPIO functions return the bitmask of the GPIO register. Fix this by ignoring the bitmask and always returning 0. The SSB GPIO functions can't fail. Signed-off-by: Michael Buesch <mb@bu3sch.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01auxdisplay: remove PARPORT dependencyH Hartley Sweeten
Remove PARPORT dependency for Auxiliary Display support. This is not needed since the dependency for the KS0108 driver is PARPORT_PC. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01remove unused include/asm-generic/dma-mapping.hFUJITA Tomonori
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01filesystem freeze: allow SysRq emergency thaw to thaw frozen filesystemsEric Sandeen
Now that the filesystem freeze operation has been elevated to the VFS, and is just an ioctl away, some sort of safety net for unintentionally frozen root filesystems may be in order. The timeout thaw originally proposed did not get merged, but perhaps something like this would be useful in emergencies. For example, freeze /path/to/mountpoint may freeze your root filesystem if you forgot that you had that unmounted. I chose 'j' as the last remaining character other than 'h' which is sort of reserved for help (because help is generated on any unknown character). I've tested this on a non-root fs with multiple (nested) freezers, as well as on a system rendered unresponsive due to a frozen root fs. [randy.dunlap@oracle.com: emergency thaw only if CONFIG_BLOCK enabled] Signed-off-by: Eric Sandeen <sandeen@redhat.com> Cc: Takashi Sato <t-sato@yk.jp.nec.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01lib/rbtree.c: optimize rb_erase()Wolfram Strepp
Tfour 4 redundant if-conditions in function __rb_erase_color() in lib/rbtree.c are removed. In pseudo-source-code, the structure of the code is as follows: if ((!A || B) && (!C || D)) { . . . } else { if (!C || D) {//if this is true, it implies: (A == true) && (B == false) if (A) {//hence this always evaluates to 'true'... . } . //at this point, C always becomes true, because of: __rb_rotate_right/left(); //and: other = parent->rb_right/left; } . . if (C) {//...and this too ! . } } Signed-off-by: Wolfram Strepp <wstrepp@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Andrea Arcangeli <andrea@qumranet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01loop: add ioctl to resize a loop deviceJ. R. Okajima
Add the ability to 'resize' the loop device on the fly. One practical application is a loop file with XFS filesystem, already mounted: You can easily enlarge the file (append some bytes) and then call ioctl(fd, LOOP_SET_CAPACITY, new); The loop driver will learn about the new size and you can use xfs_growfs later on, which will allow you to use full capacity of the loop file without the need to unmount. Test app: #include <linux/fs.h> #include <linux/loop.h> #include <sys/ioctl.h> #include <sys/stat.h> #include <sys/types.h> #include <assert.h> #include <errno.h> #include <fcntl.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #define _GNU_SOURCE #include <getopt.h> char *me; void usage(FILE *f) { fprintf(f, "%s [options] loop_dev [backend_file]\n" "-s, --set new_size_in_bytes\n" "\twhen backend_file is given, " "it will be expanded too while keeping the original contents\n", me); } struct option opts[] = { { .name = "set", .has_arg = 1, .flag = NULL, .val = 's' }, { .name = "help", .has_arg = 0, .flag = NULL, .val = 'h' } }; void err_size(char *name, __u64 old) { fprintf(stderr, "size must be larger than current %s (%llu)\n", name, old); } int main(int argc, char *argv[]) { int fd, err, c, i, bfd; ssize_t ssz; size_t sz; __u64 old, new, append; char a[BUFSIZ]; struct stat st; FILE *out; char *backend, *dev; err = EINVAL; out = stderr; me = argv[0]; new = 0; while ((c = getopt_long(argc, argv, "s:h", opts, &i)) != -1) { switch (c) { case 's': errno = 0; new = strtoull(optarg, NULL, 0); if (errno) { err = errno; perror(argv[i]); goto out; } break; case 'h': err = 0; out = stdout; goto err; default: perror(argv[i]); goto err; } } if (optind < argc) dev = argv[optind++]; else goto err; fd = open(dev, O_RDONLY); if (fd < 0) { err = errno; perror(dev); goto out; } err = ioctl(fd, BLKGETSIZE64, &old); if (err) { err = errno; perror("ioctl BLKGETSIZE64"); goto out; } if (!new) { printf("%llu\n", old); goto out; } if (new < old) { err = EINVAL; err_size(dev, old); goto out; } if (optind < argc) { backend = argv[optind++]; bfd = open(backend, O_WRONLY|O_APPEND); if (bfd < 0) { err = errno; perror(backend); goto out; } err = fstat(bfd, &st); if (err) { err = errno; perror(backend); goto out; } if (new < st.st_size) { err = EINVAL; err_size(backend, st.st_size); goto out; } append = new - st.st_size; sz = sizeof(a); while (append > 0) { if (append < sz) sz = append; ssz = write(bfd, a, sz); if (ssz != sz) { err = errno; perror(backend); goto out; } append -= sz; } err = fsync(bfd); if (err) { err = errno; perror(backend); goto out; } } err = ioctl(fd, LOOP_SET_CAPACITY, new); if (err) { err = errno; perror("ioctl LOOP_SET_CAPACITY"); } goto out; err: usage(out); out: return err; } Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp> Signed-off-by: Tomas Matejicek <tomas@slax.org> Cc: <util-linux-ng@vger.kernel.org> Cc: Karel Zak <kzak@redhat.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: <linux-api@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01uml: remove useless commentsWANG Cong
These comments are useless now, remove them. Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01uml: improve error messagesWANG Cong
These error messages are from check_sysemu(), not check_ptrace(). Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01uml: don't use a too long string literalWANG Cong
uml uses a concatenated string literal to store the contents of .config, but .config file content is varaible, it can be very long. Use an array of string literals instead. Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01ubd: stop defintining MAJOR_NRChristoph Hellwig
MAJOR_NR isn't needed anymore since very early 2.5 kernels. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01pm: cleanup includesMagnus Damm
Remove unused/duplicate cruft from asm/suspend.h: - x86_32: remove unused acpi code - powerpc: remove duplicate prototypes, see linux/suspend.h Signed-off-by: Magnus Damm <damm@igel.co.jp> Cc: Paul Mundt <lethal@linux-sh.org> Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01pm: rework includes, remove arch ifdefsMagnus Damm
Make the following header file changes: - remove arch ifdefs and asm/suspend.h from linux/suspend.h - add asm/suspend.h to disk.c (for arch_prepare_suspend()) - add linux/io.h to swsusp.c (for ioremap()) - x86 32/64 bit compile fixes Signed-off-by: Magnus Damm <damm@igel.co.jp> Cc: Paul Mundt <lethal@linux-sh.org> Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01alpha: convert u64 to unsigned long longRandy Dunlap
Convert alpha architecture to use u64 as unsigned long long. This is being done so that (a) all arches use u64 as unsigned long long and (b) printk of a u64 as %ll[ux] will not generate format warnings by gcc. The only gcc cross-compiler that I have is 4.0.2, which generates errors about miscompiling __weak references, so I have commented out that line in compiler-gcc4.h so that most of these compile, but more builds and real machine testing would be Real Good. [akpm@linux-foundation.org: fix warning] [akpm@linux-foundation.org: fix build] [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> From: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01alpha: xchg/cmpxchg cleanup and fixesIvan Kokshaysky
- "_local" versions of xchg/cmpxchg functions duplicate code of non-local ones (quite a few pages of assembler), except memory barriers. We can generate these two variants from a single header file using simple macros; - convert xchg macro back to inline function using always_inline attribute; - use proper argument types for cmpxchg_u8/u16 functions to fix a problem with negative arguments. Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Richard Henderson <rth@twiddle.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01MAINTAINERS: add the missing linux alpha port mailling listCheng Renquan
Signed-off-by: Cheng Renquan <crquan@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01alpha: fix macrosRoel Kluin
When this macros isn't called with 'fixup', e.g. with foo this will incorectly expand to foo->foo.bits.errreg Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Richard Henderson <rth@twiddle.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01shmem: writepage directly to swapHugh Dickins
Synopsis: if shmem_writepage calls swap_writepage directly, most shmem swap loads benefit, and a catastrophic interaction between SLUB and some flash storage is avoided. shmem_writepage() has always been peculiar in making no attempt to write: it has just transferred a shmem page from file cache to swap cache, then let that page make its way around the LRU again before being written and freed. The idea was that people use tmpfs because they want those pages to stay in RAM; so although we give it an overflow to swap, we should resist writing too soon, giving those pages a second chance before they can be reclaimed. That was always questionable, and I've toyed with this patch for years; but never had a clear justification to depart from the original design. It became more questionable in 2.6.28, when the split LRU patches classed shmem and tmpfs pages as SwapBacked rather than as file_cache: that in itself gives them more resistance to reclaim than normal file pages. I prepared this patch for 2.6.29, but the merge window arrived before I'd completed gathering statistics to justify sending it in. Then while comparing SLQB against SLUB, running SLUB on a laptop I'd habitually used with SLAB, I found SLUB to run my tmpfs kbuild swapping tests five times slower than SLAB or SLQB - other machines slower too, but nowhere near so bad. Simpler "cp -a" swapping tests showed the same. slub_max_order=0 brings sanity to all, but heavy swapping is too far from normal to justify such a tuning. The crucial factor on that laptop turns out to be that I'm using an SD card for swap. What happens is this: By default, SLUB uses order-2 pages for shmem_inode_cache (and many other fs inodes), so creating tmpfs files under memory pressure brings lumpy reclaim into play. One subpage of the order is chosen from the bottom of the LRU as usual, then the other three picked out from their random positions on the LRUs. In a tmpfs load, many of these pages will be ones which already passed through shmem_writepage, so already have swap allocated. And though their offsets on swap were probably allocated sequentially, now that the pages are picked off at random, their swap offsets are scattered. But the flash storage on the SD card is very sensitive to having its writes merged: once swap is written at scattered offsets, performance falls apart. Rotating disk seeks increase too, but less disastrously. So: stop giving shmem/tmpfs pages a second pass around the LRU, write them out to swap as soon as their swap has been allocated. It's surely possible to devise an artificial load which runs faster the old way, one whose sizing is such that the tmpfs pages on their second pass are the ones that are wanted again, and other pages not. But I've not yet found such a load: on all machines, under the loads I've tried, immediate swap_writepage speeds up shmem swapping: especially when using the SLUB allocator (and more effectively than slub_max_order=0), but also with the others; and it also reduces the variance between runs. How much faster varies widely: a factor of five is rare, 5% is common. One load which might have suffered: imagine a swapping shmem load in a limited mem_cgroup on a machine with plenty of memory. Before 2.6.29 the swapcache was not charged, and such a load would have run quickest with the shmem swapcache never written to swap. But now swapcache is charged, so even this load benefits from shmem_writepage directly to swap. Apologies for the #ifndef CONFIG_SWAP swap_writepage() stub in swap.h: it's silly because that will never get called; but refactoring shmem.c sensibly according to CONFIG_SWAP will be a separate task. Signed-off-by: Hugh Dickins <hugh@veritas.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01vmscan: fix it to take care of nodemaskKAMEZAWA Hiroyuki
try_to_free_pages() is used for the direct reclaim of up to SWAP_CLUSTER_MAX pages when watermarks are low. The caller to alloc_pages_nodemask() can specify a nodemask of nodes that are allowed to be used but this is not passed to try_to_free_pages(). This can lead to unnecessary reclaim of pages that are unusable by the caller and int the worst case lead to allocation failure as progress was not been make where it is needed. This patch passes the nodemask used for alloc_pages_nodemask() to try_to_free_pages(). Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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>
2009-04-01ramfs-nommu: use generic lru cacheJohannes Weiner
Instead of open-coding the lru-list-add pagevec batching when expanding a file mapping from zero, defer to the appropriate page cache function that also takes care of adding the page to the lru list. This is cleaner, saves code and reduces the stack footprint by 16 words worth of pagevec. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David Howells <dhowells@redhat.com> Cc: Nick Piggin <npiggin@suse.de> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <peterz@infradead.com> Cc: MinChan Kim <minchan.kim@gmail.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com> Cc: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01vmscan: print shrink_slab symbol name on negative shrinker objectsDavid Rientjes
When a shrinker has a negative number of objects to delete, the symbol name of the shrinker should be printed, not shrink_slab. This also makes the error message slightly more informative. Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01nommu: make CONFIG_UNEVICTABLE_LRU available when CONFIG_MMU=nDavid Howells
Make CONFIG_UNEVICTABLE_LRU available when CONFIG_MMU=n. There's no logical reason it shouldn't be available, and it can be used for ramfs. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Greg Ungerer <gerg@snapgear.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Rik van Riel <riel@redhat.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Enrik Berkhan <Enrik.Berkhan@ge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01nommu: there is no mlock() for NOMMU, so don't provide the bitsDavid Howells
The mlock() facility does not exist for NOMMU since all mappings are effectively locked anyway, so we don't make the bits available when they're not useful. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Greg Ungerer <gerg@snapgear.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Rik van Riel <riel@redhat.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Enrik Berkhan <Enrik.Berkhan@ge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01mm: use debug_kmap_atomicAkinobu Mita
Use debug_kmap_atomic in kmap_atomic, kmap_atomic_pfn, and iomap_atomic_prot_pfn. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01mm: introduce debug_kmap_atomicAkinobu Mita
x86 has debug_kmap_atomic_prot() which is error checking function for kmap_atomic. It is usefull for the other architectures, although it needs CONFIG_TRACE_IRQFLAGS_SUPPORT. This patch exposes it to the other architectures. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01mm: page_mkwrite change prototype to match fault: fix sysfsHugh Dickins
Fix warnings and return values in sysfs bin_page_mkwrite(), fixing fs/sysfs/bin.c: In function `bin_page_mkwrite': fs/sysfs/bin.c:250: warning: passing argument 2 of `bb->vm_ops->page_mkwrite' from incompatible pointer type fs/sysfs/bin.c: At top level: fs/sysfs/bin.c:280: warning: initialization from incompatible pointer type Expects to have my [PATCH next] sysfs: fix some bin_vm_ops errors Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <npiggin@suse.de> Cc: "Eric W. Biederman" <ebiederm@aristanetworks.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01fs: fix page_mkwrite error cases in core code and btrfsNick Piggin
page_mkwrite is called with neither the page lock nor the ptl held. This means a page can be concurrently truncated or invalidated out from underneath it. Callers are supposed to prevent truncate races themselves, however previously the only thing they can do in case they hit one is to raise a SIGBUS. A sigbus is wrong for the case that the page has been invalidated or truncated within i_size (eg. hole punched). Callers may also have to perform memory allocations in this path, where again, SIGBUS would be wrong. The previous patch ("mm: page_mkwrite change prototype to match fault") made it possible to properly specify errors. Convert the generic buffer.c code and btrfs to return sane error values (in the case of page removed from pagecache, VM_FAULT_NOPAGE will cause the fault handler to exit without doing anything, and the fault will be retried properly). This fixes core code, and converts btrfs as a template/example. All other filesystems defining their own page_mkwrite should be fixed in a similar manner. Acked-by: Chris Mason <chris.mason@oracle.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01mm: page_mkwrite change prototype to match faultNick Piggin
Change the page_mkwrite prototype to take a struct vm_fault, and return VM_FAULT_xxx flags. There should be no functional change. This makes it possible to return much more detailed error information to the VM (and also can provide more information eg. virtual_address to the driver, which might be important in some special cases). This is required for a subsequent fix. And will also make it easier to merge page_mkwrite() with fault() in future. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Chris Mason <chris.mason@oracle.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Artem Bityutskiy <dedekind@infradead.org> Cc: Felix Blyakher <felixb@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01mm: enable hashdist by default on 64bit NUMAAnton Blanchard
On PowerPC we allocate large boot time hashes on node 0. This leads to an imbalance in the free memory, for example on a 64GB box (4 x 16GB nodes): Free memory: Node 0: 97.03% Node 1: 98.54% Node 2: 98.42% Node 3: 98.53% If we switch to using vmalloc (like ia64 and x86-64) things are more balanced: Free memory: Node 0: 97.53% Node 1: 98.35% Node 2: 98.33% Node 3: 98.33% For many HPC applications we are limited by the free available memory on the smallest node, so even though the same amount of memory is used the better balancing helps. Since all 64bit NUMA capable architectures should have sufficient vmalloc space, it makes sense to enable it via CONFIG_64BIT. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Richard Henderson <rth@twiddle.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01mm: fix proc_dointvec_userhz_jiffies "breakage"Alexey Dobriyan
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=9838 On i386, HZ=1000, jiffies_to_clock_t() converts time in a somewhat strange way from the user's point of view: # echo 500 >/proc/sys/vm/dirty_writeback_centisecs # cat /proc/sys/vm/dirty_writeback_centisecs 499 So, we have 5000 jiffies converted to only 499 clock ticks and reported back. TICK_NSEC = 999848 ACTHZ = 256039 Keeping in-kernel variable in units passed from userspace will fix issue of course, but this probably won't be right for every sysctl. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01generic debug pageallocAkinobu Mita
CONFIG_DEBUG_PAGEALLOC is now supported by x86, powerpc, sparc64, and s390. This patch implements it for the rest of the architectures by filling the pages with poison byte patterns after free_pages() and verifying the poison patterns before alloc_pages(). This generic one cannot detect invalid page accesses immediately but invalid read access may cause invalid dereference by poisoned memory and invalid write access can be detected after a long delay. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01memdup_user(): introduceLi Zefan
I notice there are many places doing copy_from_user() which follows kmalloc(): dst = kmalloc(len, GFP_KERNEL); if (!dst) return -ENOMEM; if (copy_from_user(dst, src, len)) { kfree(dst); return -EFAULT } memdup_user() is a wrapper of the above code. With this new function, we don't have to write 'len' twice, which can lead to typos/mistakes. It also produces smaller code and kernel text. A quick grep shows 250+ places where memdup_user() *may* be used. I'll prepare a patchset to do this conversion. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01hugetlb: chg cannot become less than 0Roel Kluin
chg is unsigned, so it cannot be less than 0. Also, since region_chg returns long, let vma_needs_reservation() forward this to alloc_huge_page(). Store it as long as well. all callers cast it to long anyway. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Adam Litke <agl@us.ibm.com> Cc: Johannes Weiner <hannes@saeurebad.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01mm: remove pagevec_swap_free()KOSAKI Motohiro
pagevec_swap_free() is now unused. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Rik van Riel <riel@redhat.com> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01mm: don't free swap slots on page deactivationJohannes Weiner
The pagevec_swap_free() at the end of shrink_active_list() was introduced in 68a22394 "vmscan: free swap space on swap-in/activation" when shrink_active_list() was still rotating referenced active pages. In 7e9cd48 "vmscan: fix pagecache reclaim referenced bit check" this was changed, the rotating removed but the pagevec_swap_free() after the rotation loop was forgotten, applying now to the pagevec of the deactivation loop instead. Now swap space is freed for deactivated pages. And only for those that happen to be on the pagevec after the deactivation loop. Complete 7e9cd48 and remove the rest of the swap freeing. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01mm: move pagevec stripping to save unlock-relockJohannes Weiner
In shrink_active_list() after the deactivation loop, we strip buffer heads from the potentially remaining pages in the pagevec. Currently, this drops the zone's lru lock for stripping, only to reacquire it again afterwards to update statistics. It is not necessary to strip the pages before updating the stats, so move the whole thing out of the protected region and save the extra locking. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: MinChan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01mm: reintroduce and deprecate rlimit based access for SHM_HUGETLBRavikiran G Thirumalai
Allow non root users with sufficient mlock rlimits to be able to allocate hugetlb backed shm for now. Deprecate this though. This is being deprecated because the mlock based rlimit checks for SHM_HUGETLB is not consistent with mmap based huge page allocations. Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Reviewed-by: Mel Gorman <mel@csn.ul.ie> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: Adam Litke <agl@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>