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* [PATCH] Shrinks sizeof(files_struct) and better layoutEric Dumazet2006-03-23
| | | | | | | | | | | | | | | | | | | | | | | | 1) Reduce the size of (struct fdtable) to exactly 64 bytes on 32bits platforms, lowering kmalloc() allocated space by 50%. 2) Reduce the size of (files_struct), using a special 32 bits (or 64bits) embedded_fd_set, instead of a 1024 bits fd_set for the close_on_exec_init and open_fds_init fields. This save some ram (248 bytes per task) as most tasks dont open more than 32 files. D-Cache footprint for such tasks is also reduced to the minimum. 3) Reduce size of allocated fdset. Currently two full pages are allocated, that is 32768 bits on x86 for example, and way too much. The minimum is now L1_CACHE_BYTES. UP and SMP should benefit from this patch, because most tasks will touch only one cache line when open()/close() stdin/stdout/stderr (0/1/2), (next_fd, close_on_exec_init, open_fds_init, fd_array[0 .. 2] being in the same cache line) Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] percpu data: only iterate over possible CPUsEric Dumazet2006-02-05
| | | | | | | | | | | | | | | | | | | | | | | percpu_data blindly allocates bootmem memory to store NR_CPUS instances of cpudata, instead of allocating memory only for possible cpus. As a preparation for changing that, we need to convert various 0 -> NR_CPUS loops to use for_each_cpu(). (The above only applies to users of asm-generic/percpu.h. powerpc has gone it alone and is presently only allocating memory for present CPUs, so it's currently corrupting memory). Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: James Bottomley <James.Bottomley@steeleye.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Jens Axboe <axboe@suse.de> Cc: Anton Blanchard <anton@samba.org> Acked-by: William Irwin <wli@holomorphy.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Fix the fdtable freeing in the case of vmalloced fdset/arraysDipankar Sarma2005-09-14
| | | | | | | | | | | | | | | Noted by David Miller: "The bug is that free_fd_array() takes a "num" argument, but when calling it from __free_fdtable() we're instead passing in the size in bytes (ie. "num * sizeof(struct file *)")." Yes it is a bug. I think I messed it up while merging newer changes with an older version where I was using size in bytes to optimize. Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] files: files struct with RCUDipankar Sarma2005-09-09
| | | | | | | | | | | | | | | | | | | | | Patch to eliminate struct files_struct.file_lock spinlock on the reader side and use rcu refcounting rcuref_xxx api for the f_count refcounter. The updates to the fdtable are done by allocating a new fdtable structure and setting files->fdt to point to the new structure. The fdtable structure is protected by RCU thereby allowing lock-free lookup. For fd arrays/sets that are vmalloced, we use keventd to free them since RCU callbacks can't sleep. A global list of fdtable to be freed is not scalable, so we use a per-cpu list. If keventd is already handling the current cpu's work, we use a timer to defer queueing of that work. Since the last publication, this patch has been re-written to avoid using explicit memory barriers and use rcu_assign_pointer(), rcu_dereference() premitives instead. This required that the fd information is kept in a separate structure (fdtable) and updated atomically. 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 Sarma2005-09-09
| | | | | | | | | | | | | | | 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>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-16
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!