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Andrea Arcangeli: Linux 2.4.5pre2aa1

May 16, 2001, 00:11 (0 Talkback[s])
(Other stories by Andrea Arcangeli)

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Subject: 2.4.5pre2aa1
Date: Tue, 15 May 2001 23:59:16 +0200
From: Andrea Arcangeli 



Detailed description of 2.4.5pre2aa1 follows.

---------------------------------------------------------------------
------ 00_alpha-illegal-irq-1

        Be verbose for MAX_ILLEGAL_IRQS times if an invalid irq number
        is getting run.

        (debugging)

00_alpha-ksyms-1

        Export a few alpha-arch symbols needed by modules.

        (recommended to avoid compilation troubles)

00_alpha-large-vmalloc-1

        Drop the CONFIG_LARGE_VMALLOC selection from the
        arch/alpha/config.in, the large-vmalloc feature is racy and it can
        destabilize the machine, fixing it isn't worthwhile because
        nobody needs more than 8Gigabytes of ram in vmalloc memory,
        not even tux on the 256G boxes will ever need that.

        (recommended)

00_alpha-modrace-1

        Fix alpha races between module insmod/rmmod and the page fault
        fixmap lookup.

        (recommended)

00_alpha-numa-10

        Fully support wildfire machines with all kind of NUMA memory
        configuration, plus it optimizes the allocation on per node
        basis to boost the performance on the NUMA boxes. Right now
        CONFIG_WILDFIRE needs to be selected to take advantage of this
        feature. (CONFIG_GENERIC + CONFIG_DISCONTIGMEM=y and
        CONFIG_NUMA=y will work fine as well but it won't take
        advantage of the new feature. It also fixes many memory
        management bit in the core linux allocator in the common code,
        mostly to avoid wasting static memory.

        (recommended)

00_alpha-sched-yield-1

        Fixes SCHED_YIELD on the alpha arch for UP compiles.

        (recommended)

00_alpha-show_stack-1

        Implements the show_stack() call used often by some common
        code, mostly to allow compilation, things like tux needs it.

        (nice to have)

00_alpha-tlb-page-sym-1

        Drops a not necessary export on the alpha port.

        (recommended)

00_buffer-2

        Reschedule during oom while allocating buffers, still getblk
        can deadlock with oom but this will hide it pretty well as
        it won't loop in a tight loop anymore.

        (recommended)

00_cachelinealigned-in-smp-1

        Moves the pagecache_lock and the VM pagemap_lru_lock in two
        different L1 cachelines to avoid contention, mostly useful on
        the alpha where the spinlocks uses load locked store
        conditional loops (and we don't want to loop).

        (nice to have)

00_copy-user-lat-2

        Put the rechedule points into copy-user calls, with lots of
        cache large read/writes could otherwise _never_ reschedule
        once until they returns to userspace.

        (recommended)

00_cpus_allowed-1

        Fixes a bug in the cpu affinity in-kernel API, bug was fatal
        for ksoftirqd.

        (recommended)

00_double-buffer-pass-1

        Avoids looping two times for no good reason into the lru lists
        of the buffer cache (the double loop was an unreliable hack
        from the prehistory that survided 'till today).

        (nice to have)

00_exception-table-1

        Avoids a compilation warning when compiling without modules.

        (very minor thing)

00_highmem-deadlock-3

        Fixes an highmem deadlock using a reserved pool for the bounce
        buffers.

        (recommended)

00_highmem-debug-1

        Allows people with x86 machines with less than 1G of ram to
        test the highmem code.

        (debugging)

00_ia32-bootmem-corruption-1

        Fixes the x86 boot stage to finish initializing all the
        reserved memory before starting allocating memory.

        (recommended)

00_ipv6-null-oops-1

        Fixes null pointer oops.

        (recommended)

00_jens-loop-noop-nobounce-1

        Skips the bounces with the null transfer function.

        (nice to have)

00_ksoftirqd-4

        Avoids 1/HZ latency for the softirq if the softirq is marked
        again pending when do_softirq() finished and the machine is
        otherwise idle, it also fixes the case of a softirq re-marking
        itself runnable by delegating to the scheduler the balance of
        the softirq load like if it would be an normal task.

        (nice to have)

00_kupdate-large-interval-1

        Allows to set large interval for the kupdate runs, this is
        useful on the laptops, instead of sigstopping ksoftirqd it's
        nicer to set a large interval for example of the order of one
        hour (do that at your own risk of course, doing that is not
        recommended unless you know what you're doing).

        (nice to have)

00_lvm-0.9.1_beta7-4

        Updates to the lvmbeta7 with fixes for the lv hardsectsize
        estimantion based on the max hardsectsize of the underlying
        pv, plus it has some other tons of fixes and it is a must have
        for the 64bit archs as the IOP silenty changed for those
        platforms.

        (recommended)

00_max_readahead-1

        Increases the max_readahead to allow the blkdev to read with
        512k scsi commands when possible.

        (nice to have)

00_msync-fb0-1

        Fixes oopses while running msync on a region of virtual memory
        that maps to reserved memory.

        (recommended)

00_nfs-corruption-3

        Production fix for the nfs map_shared fs data
        corruption. Other design solutions are discussed and the long
        term fix might be different but all the other approches are
        more invasive and risky, while this one is obviously right and
        the most approriate for production.

        (recommended)

00_numa-sched-6

        Implements a basic numa scheduler with a per node runqueue
        that boosts the perforormance on numa boxes. It also enables
        and somewhere fixes the last_idle heuristic in the smp
        scheduler.

        The numa part doesn't impose any runtime overhead when
        CONFIG_NUMA_SCHED is not set.

        (nice to have)

00_o_direct-6

        Implements O_DIRECT zerocopy direct I/O in a filesystem
        indipendent fascion, currently it's only available on ext2,
        but it will be easy to let the other of fs to take advantage
        of it too.

        (nice to have)

00_pagetable-fast-2

        Enables the usage of the per-cpu quicklists for the pte/pgd to
        optimize the cache affinity and footprint.

        (nice to have)

00_peekurgdata-1

        Allows MSG_PEEK to work on the urgent (aka out of band)
        receive queue as well, needed for tux. (nice to have)

00_rwsem-11

        Alternate implementation for the rwsem, the x86 asm version is
        simpler in the slow path and it provides a faster up_write
        fast path, the C-spinlock version is much faster too.

        (nice to have)

00_sched-yield-1

        Fixes a bug in sched_yield, where SCHED_YIELD needs to be
        cleared after a schedule() if no other task was runnable,
        otherwise the next schedule() would inherit the SCHED_YIELD
        behaviour even if a SCHED_YIELD wasn't requested anymore.

        (nice to have)

00_show_regs-1

        Makes SYSRQ+P more verbose.

        (debugging)

00_slab-lists-1

        Rewrites the slab cache handling for partial and completly
        free slab objects, always provides LIFO behaviour from all
        the lists to reduce the cache misses, while previously the
        completly free slab objects were reallocated with a less
        optimal FIFO policy. It also cleanups the code.

        (nice to have)

00_softirq-SMP-fixes-3

        Fixes an SMP race in the softirq code on archs like the alpha
        where the atomic_t and bitop operations aren't memory barriers
        as well.

        (recommended)

00_sync-page-1

        Avoids suprious unplug of the tq_disk task queue while waiting
        I/O completion.

        (nice to have)

00_timer_t-2

        Defines the timer_t type in one single place.

        (nice to have)

00_waitqueue-2

        Setups the not yet visible waitqueue flags outside the
        critical section.

        (nice to have)

00_x86-systable-1

        Fills the end of the syscall table automatically, it is off by
        one without this patch.

        (nice to have)

00_xircom-tulip-cb-arjanv-1

        No need of ifconfig eth0 promisc on the xircom card with this
        driver.

        (nice to have)

10_no-virtual-1

        Avoids wasting tons of memory if highmem is not selected (like
        in all the 64bit ports).

        (nice to have)

10_parent-timeslice-7

        Fixes a scheduler unfairness generated by the parent-timeslice
        logic.

        (recommended)

10_read_ahead-2

        Setups readahead for lvm [global, hacking around read/write
        callbacks is broken] and drops sensless limits.

        (recommended)

20_share-timeslice-2

        Reschedule the child first but share the timeslice with the
        parent (I never triggered a single userspace bug with this
        correct patch)

        (nice to have)

The below patches aren't included by default but they can be applied
incrementally if tux is needed. TUX patches are been developed by
Ingo Molnar.

30_atomic-alloc-1

        Defines a PF_ATOMICALLOC that won't sleep watiting memory to
        become available.

        (needed by tux)

30_atomic-lookup-1

        Implements an O_ATOMICLOOKUP flag to avoid entering the
        filesystem code that could wait for I/O in open, open will
        return -EWOULDBLOCKIO if the lookup wasn't doable in dcache.

        (needed by tux for the asynchronous vfs lookups)

30_net-exports-1

        Exports some networking function so that tux can be compiled
        as module,  and splits the sock_map_file functionality away
        from sock_map_fd.

        (needed by tux)

30_pagecache-atomic-1

        Defines a do_generic_file_read_atomic that implements
        nonblocking reads from cache, if information wasn't in cache
        the descriptor error flag is set to -EWOULDBLOCKIO.

        (needed by tux to implement asynchronous read I/O)

30_tux-1

        tux core.

        (nice to have)

30_tux-data-1

        Adds a tux_data private pointer to the sock structure.

        (needed by tux)

30_tux-dprintk-1

        Defines tux_Dprintk.

        (needed by tux)

30_tux-exports-1

        Exports to modules the in-kernel syscalls.

        (needed by tux)

30_tux-kstat-1

        Defines additional kstats for tux.

30_tux-process-1

        Defines per-process callbacks for tux.
30_tux-syscall-1

        Implements the tux-syscall, it's the one executed by the
        userspace tux program to fire up, shutdown and control the tux
        kernel threads.

        (needed by tux)

30_tux-sysctl-1

        Defines the symbolic names for the tux sysctl.

        (needed by tux)

30_tux-vfs-1

        Adds a per-dentry tux private data.

        (needed by tux)

31_tux-logger-1

        Aligns correctly the tux logentry for 8 byte cachelines too.

---------------------------------------------------------------------
------

The 2.4.5pre2aa1 patch is here:

        ftp://ftp.us.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/
2.4.5pre2aa1.bz2

As usual all the separate patches are in:

        ftp://ftp.us.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.2/
2.4.5pre2aa1/

and they can be applyed in `ls` order to generate the
2.4.5pre2aa1.bz2 kernel.

Have fun.

Andrea