On Thu, Sep 24, 2015 at 11:24:51AM +0800, Baoquan He wrote: > People reported that when allocating crashkernel memory using > ",high" and ",low" syntax, there were cases where the reservation > of the "high" portion succeeds, but the reservation of the "low" > portion fails. Then kexec can load kdump kernel successfully, but > the boot of kdump kernel fails as there's no low memory. This is > because allocation of low memory for kdump kernel can fail on large > systems for reasons. E.g it could be manually specified crashkernel > low memory is too large to find in memblock region. > > In this patch add return value for reserve_crashkernel_low. Then > try to reserve crashkernel low memory after crashkernel high memory > has been allocated. If crashkernel low memory reservation failed > free crashkernel high memory and return. User can take measures > when they found kdump kernel cann't be loaded successfully. > > Signed-off-by: Baoquan He <[email protected]> > --- > v1->v2: > Boris commented that error value EINVAL is negative, should > use "return -EINVAL". > > v2->v3: > Yinghai pointed out that during memblock_reserve, we could double > the memblock reserve array. New memblock reserve could be overlapped > with range for crashkernel high. So we have to reserve crashkernel > high firstly, then free it if crashkernel low memory allocation > failed. > > v3->v4: > Dave suggested using "return -ENOMEM" when low memory reservation > failed and printing failure message anyway. > > v4->v5: > Andrew suggested changing the content of failure message and taking > higher severity KERN_ERR. > > arch/x86/kernel/setup.c | 20 +++++++++++--------- > 1 file changed, 11 insertions(+), 9 deletions(-)
Reviewed-by: Joerg Roedel <[email protected]> The patch is also in SLES for some time now and was successfully tested there. Joerg -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
