On Fri, 2010-11-19 at 13:42 -0800, Greg KH wrote: > 2.6.32-stable review patch. If anyone has any objections, please let us know. > > ------------------ > > From: Cliff Wickman <cpw at sgi.com> > > commit 3ee48b6af49cf534ca2f481ecc484b156a41451d upstream. > > During the reading of /proc/vmcore the kernel is doing > ioremap()/iounmap() repeatedly. And the buildup of un-flushed > vm_area_struct's is causing a great deal of overhead. (rb_next() > is chewing up most of that time). > > This solution is to provide function set_iounmap_nonlazy(). It > causes a subsequent call to iounmap() to immediately purge the > vma area (with try_purge_vmap_area_lazy()). > > With this patch we have seen the time for writing a 250MB > compressed dump drop from 71 seconds to 44 seconds. [...] Useful, but it doesn't seem to meet the criteria for stable updates. Ben. -- Ben Hutchings Once a job is fouled up, anything done to improve it makes it worse. -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 828 bytes Desc: This is a digitally signed message part URL: <http://lists.infradead.org/pipermail/kexec/attachments/20101120/9177fec3/attachment.sig>
