Daniel Jordan <daniel.m.jordan@xxxxxxxxxx> writes: > On Tue, Nov 16, 2021 at 12:12:37PM +0530, Aneesh Kumar K.V wrote: >> sys_set_mempolicy_home_node((unsigned long)p, nr_pages * page_size, >> home_node, 0); > > What about sys_mbind_home_node so the name is better aligned with mbind, > since both operate on vma policy? The syscall might or might not be > extended to task memory policy, but vma policy is what we're using this > for today. I used the name set_mempolicy_home_node, because we are setting the home for a memory policy. I find the term mbind confusing. > > >> +SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, len, >> + unsigned long, home_node, unsigned long, flags) > > mbind does untagged_addr(addr), why doesn't this need to do the same? > Seems like tagged addresses could be passed here too. > updated modified mm/mempolicy.c @@ -1489,6 +1489,7 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le unsigned long end; int err = -ENOENT; + start = untagged_addr(start); if (start & ~PAGE_MASK) return -EINVAL; /* > >> + /* >> + * Only update home node if there is an existing vma policy >> + */ >> + if (!new) >> + continue; >> + new->home_node = home_node; >> + err = mbind_range(mm, vmstart, vmend, new); > > I think you need an mpol_put(new) here since @new is dup'ed again during > mbind_range > vma_replace_policy. updated @@ -1536,6 +1540,7 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, le new->home_node = home_node; err = mbind_range(mm, vmstart, vmend, new); + mpol_put(new); if (err) break; } Thanks for your review -aneesh
