Re: [RFC][PATCH 4/6] arm, mm: Convert arm to generic tlb

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

On Thu, 2012-05-17 at 18:01 +0100, Catalin Marinas wrote:
> > So the RCU code can from ppc in commit
> > 267239116987d64850ad2037d8e0f3071dc3b5ce, which has similar behaviour.
> > Also I suspect the mm_users < 2 test will be incorrect for ARM since
> > even the one user can be concurrent with your speculation engine.
> That's correct. 

(I'm not sending this... really :-)

commit cd94154cc6a28dd9dc271042c1a59c08d26da886
Author: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Date:   Wed Apr 11 14:28:07 2012 +0200

    [S390] fix tlb flushing for page table pages
    Git commit 36409f6353fc2d7b6516e631415f938eadd92ffa "use generic RCU
    page-table freeing code" introduced a tlb flushing bug. Partially revert
    the above git commit and go back to s390 specific page table flush code.
    For s390 the TLB can contain three types of entries, "normal" TLB
    page-table entries, TLB combined region-and-segment-table (CRST) entries
    and real-space entries. Linux does not use real-space entries which
    leaves normal TLB entries and CRST entries. The CRST entries are
    intermediate steps in the page-table translation called translation paths.
    For example a 4K page access in a three-level page table setup will
    create two CRST TLB entries and one page-table TLB entry. The advantage
    of that approach is that a page access next to the previous one can reuse
    the CRST entries and needs just a single read from memory to create the
    page-table TLB entry. The disadvantage is that the TLB flushing rules are
    more complicated, before any page-table may be freed the TLB needs to be
    In short: the generic RCU page-table freeing code is incorrect for the
    CRST entries, in particular the check for mm_users < 2 is troublesome.
    This is applicable to 3.0+ kernels.
    Cc: <stable@xxxxxxxxxxxxxxx>
    Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at

[Other Archives]     [Linux Kernel Newbies]     [Linux Driver Development]     [Fedora Kernel]     [Linux Kernel Testers]     [Linux SH]     [Linux Omap]     [Linux Kbuild]     [Linux Tape]     [Linux Input]     [Linux Kernel Janitors]     [Linux Kernel Packagers]     [Linux Doc]     [Linux Man Pages]     [Linux API]     [Linux Memory Management]     [Linux Modules]     [Linux Standards]     [Kernel Announce]     [Netdev]     [Git]     [Linux PCI]     Linux CAN Development     [Linux I2C]     [Linux RDMA]     [Linux NUMA]     [Netfilter]     [Netfilter Devel]     [SELinux]     [Bugtraq]     [FIO]     [Linux Perf Users]     [Linux Serial]     [Linux PPP]     [Linux ISDN]     [Linux Next]     [Kernel Stable Commits]     [Linux Tip Commits]     [Kernel MM Commits]     [Linux Security Module]     [AutoFS]     [Filesystem Development]     [Ext3 Filesystem]     [Linux bcache]     [Ext4 Filesystem]     [Linux BTRFS]     [Linux CEPH Filesystem]     [Linux XFS]     [XFS]     [Linux NFS]     [Linux CIFS]     [Ecryptfs]     [Linux NILFS]     [Linux Cachefs]     [Reiser FS]     [Initramfs]     [Linux FB Devel]     [Linux OpenGL]     [DRI Devel]     [Fastboot]     [Linux RT Users]     [Linux RT Stable]     [eCos]     [Corosync]     [Linux Clusters]     [LVS Devel]     [Hot Plug]     [Linux Virtualization]     [KVM]     [KVM PPC]     [KVM ia64]     [Linux Containers]     [Linux Hexagon]     [Linux Cgroups]     [Util Linux]     [Wireless]     [Linux Bluetooth]     [Bluez Devel]     [Ethernet Bridging]     [Embedded Linux]     [Barebox]     [Linux MMC]     [Linux IIO]     [Sparse]     [Smatch]     [Linux Arch]     [x86 Platform Driver]     [Linux ACPI]     [Linux IBM ACPI]     [LM Sensors]     [CPU Freq]     [Linux Power Management]     [Linmodems]     [Linux DCCP]     [Linux SCTP]     [ALSA Devel]     [Linux USB]     [Linux PA RISC]     [Linux Samsung SOC]     [MIPS Linux]     [IBM S/390 Linux]     [ARM Linux]     [ARM Kernel]     [ARM MSM]     [Tegra Devel]     [Sparc Linux]     [Linux Security]     [Linux Sound]     [Linux Media]     [Video 4 Linux]     [Linux IRDA Users]     [Linux for the blind]     [Linux RAID]     [Linux ATA RAID]     [Device Mapper]     [Linux SCSI]     [SCSI Target Devel]     [Linux SCSI Target Infrastructure]     [Linux IDE]     [Linux SMP]     [Linux AXP]     [Linux Alpha]     [Linux M68K]     [Linux ia64]     [Linux 8086]     [Linux x86_64]     [Linux Config]     [Linux Apps]     [Linux MSDOS]     [Linux X.25]     [Linux Crypto]     [DM Crypt]     [Linux Trace Users]     [Linux Btrace]     [Linux Watchdog]     [Utrace Devel]     [Linux C Programming]     [Linux Assembly]     [Dash]     [DWARVES]     [Hail Devel]     [Linux Kernel Debugger]     [Linux gcc]     [Gcc Help]     [X.Org]     [Wine]

Add to Google Powered by Linux

[Older Kernel Discussion]     [Yosemite National Park Forum]     [Large Format Photos]     [Gimp]     [Yosemite Photos]     [Stuff]