Messages in this thread | | | Date | Tue, 19 Jun 2018 15:39:11 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] tools: adding support for idle page tracking to tool |
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On Tue, 12 Jun 2018 11:32:23 -0400 Christian Hansen <chansen3@cisco.com> wrote:
> Adding a flag which will use the kernels's idle > page tracking to mark pages idle. As the tool already > prints the idle flag if set, subsequent runs will show > which pages have been accessed since last run.
That sounds useful.
This patch seems to have been prepared against the mainline kernel, so it conflicts with your "tools: modifying page-types to include shared map counts" patch. Awkward, but I seem to have got it fixed up.
> ... > > @@ -566,6 +570,30 @@ static int unpoison_page(unsigned long offset) > return 0; > } > > +static int mark_page_idle(unsigned long offset) > +{ > + static unsigned long off; > + static uint64_t buf; > + int len; > + > + if ((offset / 64 == off / 64) || buf == 0) { > + buf |= 1UL << (offset % 64); > + off = offset; > + return 0; > + } > + > + len = pwrite(page_idle_fd, &buf, 8, 8 * (off / 64)); > + if (len < 0) { > + perror("mark page idle"); > + return len; > + } > + > + buf = 1UL << (offset % 64); > + off = offset; > + > + return 0; > +}
This is a bit cumbersome. Why not this way:
static int mark_page_idle(unsigned long offset) { static unsigned long off; static uint64_t buf; int len;
if ((offset / 64 != off / 64) && buf != 0) { len = pwrite(page_idle_fd, &buf, 8, 8 * (off / 64)); if (len < 0) { perror("mark page idle"); return len; } } buf = 1UL << (offset % 64); off = offset; return 0; }
Also, it's not very clear what's going on here - the handling of offset, off and buf. Some well-crafted comments would help.
> > ... >
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