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* [PATCH] avoid unaligned access when accessing poll stackJes Sorensen2006-03-311-3/+5
| | | | | | | | | | | | | | | | | | Commit 70674f95c0a2ea694d5c39f4e514f538a09be36f: [PATCH] Optimize select/poll by putting small data sets on the stack resulted in the poll stack being 4-byte aligned on 64-bit architectures, causing misaligned accesses to elements in the array. This patch fixes it by declaring the stack in terms of 'long' instead of 'char'. Force alignment of poll and select stacks to long to avoid unaligned access on 64 bit architectures. Signed-off-by: Jes Sorensen <jes@sgi.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mark f_ops const in the inodeArjan van de Ven2006-03-281-1/+1
| | | | | | | | | | | Mark the f_ops members of inodes as const, as well as fix the ripple-through this causes by places that copy this f_ops and then "do stuff" with it. Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] use fget_light() in select/pollEric Dumazet2006-03-281-4/+6
| | | | | | Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Optimize select/poll by putting small data sets on the stackAndi Kleen2006-03-281-42/+64
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Optimize select and poll by a using stack space for small fd sets This brings back an old optimization from Linux 2.0. Using the stack is faster than kmalloc. On a Intel P4 system it speeds up a select of a single pty fd by about 13% (~4000 cycles -> ~3500) It also saves memory because a daemon hanging in select or poll will usually save one or two less pages. This can add up - e.g. if you have 10 daemons blocking in poll/select you save 40KB of memory. I did a patch for this long ago, but it was never applied. This version is a reimplementation of the old patch that tries to be less intrusive. I only did the minimal changes needed for the stack allocation. The cut off point before external memory is allocated is currently at 832bytes. The system calls always allocate this much memory on the stack. These 832 bytes are divided into 256 bytes frontend data (for the select bitmaps of the pollfds) and the rest of the space for the wait queues used by the low level drivers. There are some extreme cases where this won't work out for select and it falls back to allocating memory too early - especially with very sparse large select bitmaps - but the majority of processes who only have a small number of file descriptors should be ok. [TBD: 832/256 might not be the best split for select or poll] I suspect more optimizations might be possible, but they would be more complicated. One way would be to cache the select/poll context over multiple system calls because typically the input values should be similar. Problem is when to flush the file descriptors out though. Signed-off-by: Andi Kleen <ak@suse.de> Cc: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] select: time comparison fixesAndrew Morton2006-02-171-3/+3
| | | | | | | | | | | | | I got all of these backwards. We want to return min(input timeout, new timeout) to userspace to prevent increasing the time-remaining value. Thanks to Ernst Herzberg <earny@net4u.de> for reporting and diagnosing. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] select: fix returned timevalAndrew Morton2006-02-111-9/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With David Woodhouse <dwmw2@infradead.org> select() presently has a habit of increasing the value of the user's `timeout' argument on return. We were writing back a timeout larger than the original. We _deliberately_ round up, since we know we must wait at _least_ as long as the caller asks us to. The patch adds a couple of helper functions for magnitude comparison of timespecs and of timevals, and uses them to prevent the various poll and select functions from returning a timeout which is larger than the one which was passed in. The patch also fixes a bug in compat_sys_pselect7(): it was adding the new timeout value to the old one and was returning that. It should just return the new timeout value. (We have various handy timespec/timeval-to-from-nsec conversion functions in time.h. But this code open-codes it all). Cc: "David S. Miller" <davem@davemloft.net> Cc: Andi Kleen <ak@muc.de> Cc: Ulrich Drepper <drepper@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: george anzinger <george@mvista.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fix __user annotations in fs/select.cAl Viro2006-02-071-2/+2
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] Add pselect/ppoll system call implementationDavid Woodhouse2006-01-181-57/+291
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following implementation of ppoll() and pselect() system calls depends on the architecture providing a TIF_RESTORE_SIGMASK flag in the thread_info. These system calls have to change the signal mask during their operation, and signal handlers must be invoked using the new, temporary signal mask. The old signal mask must be restored either upon successful exit from the system call, or upon returning from the invoked signal handler if the system call is interrupted. We can't simply restore the original signal mask and return to userspace, since the restored signal mask may actually block the signal which interrupted the system call. The TIF_RESTORE_SIGMASK flag deals with this by causing the syscall exit path to trap into do_signal() just as TIF_SIGPENDING does, and by causing do_signal() to use the saved signal mask instead of the current signal mask when setting up the stack frame for the signal handler -- or by causing do_signal() to simply restore the saved signal mask in the case where there is no handler to be invoked. The first patch implements the sys_pselect() and sys_ppoll() system calls, which are present only if TIF_RESTORE_SIGMASK is defined. That #ifdef should go away in time when all architectures have implemented it. The second patch implements TIF_RESTORE_SIGMASK for the PowerPC kernel (in the -mm tree), and the third patch then removes the arch-specific implementations of sys_rt_sigsuspend() and replaces them with generic versions using the same trick. The fourth and fifth patches, provided by David Howells, implement TIF_RESTORE_SIGMASK for FR-V and i386 respectively, and the sixth patch adds the syscalls to the i386 syscall table. This patch: Add the pselect() and ppoll() system calls, providing core routines usable by the original select() and poll() system calls and also the new calls (with their semantics w.r.t timeouts). Signed-off-by: David Woodhouse <dwmw2@infradead.org> Cc: Michael Kerrisk <mtk-manpages@gmx.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] files: lock-free fd look-upDipankar Sarma2005-09-091-3/+10
| | | | | | | | | | | | With the use of RCU in files structure, the look-up of files using fds can now be lock-free. The lookup is protected by rcu_read_lock()/rcu_read_unlock(). This patch changes the readers to use lock-free lookup. Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Ravikiran Thirumalai <kiran_th@gmail.com> Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] files: break up files structDipankar Sarma2005-09-091-3/+9
| | | | | | | | | | | | | | | In order for the RCU to work, the file table array, sets and their sizes must be updated atomically. Instead of ensuring this through too many memory barriers, we put the arrays and their sizes in a separate structure. This patch takes the first step of putting the file table elements in a separate structure fdtable that is embedded withing files_struct. It also changes all the users to refer to the file table using files_fdtable() macro. Subsequent applciation of RCU becomes easier after this. Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com> Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] make some things staticAdrian Bunk2005-05-051-2/+4
| | | | | | | | | | This patch makes some needlessly global identifiers static. Signed-off-by: Adrian Bunk <bunk@stusta.de> Acked-by: Arjan van de Ven <arjanv@infradead.org> Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Linux-2.6.12-rc2Linus Torvalds2005-04-161-0/+534
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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