Messages in this thread | | | Date | Fri, 26 Mar 2004 14:28:26 +0530 | From | Suparna Bhattacharya <> | Subject | Re: [Lse-tech] Re: [PATCH] [0/6] HUGETLB memory commitment |
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On Thu, Mar 25, 2004 at 04:22:32PM -0800, Andrew Morton wrote: > Keith Owens <kaos@sgi.com> wrote: > > > > FWIW, lkcd (crash dump) treats hugetlb pages as normal kernel pages and > > dumps them, which is pointless and wastes a lot of time. To avoid > > dumping these pages in lkcd, I had to add a PG_hugetlb flag. lkcd runs
This should already be fixed in recent versions of lkcd. It uses a little bit of trickery to avoid an extra page flag -- hugetlb pages are detected as "in use" as well as reserved, unlike other reserved pages which helps identify them.
/* to track all used (compound + zero order) pages */ #define PageInuse(p) (PageCompound(p) || page_count(p))
. .
static inline int kernel_page(struct page *p) { /* Need to exclude hugetlb pages. Clue: reserved but inuse */ return (PageReserved(p) && !PageInuse(p)) || (!PageLRU(p) && PageInuse(p)); }
Regards Suparna
> > at the page level, not mm or vma, so VM_hugetlb was not available. In > > set_hugetlb_mem_size() > > > > for (j = 0; j < (HPAGE_SIZE / PAGE_SIZE); j++) { > > SetPageReserved(map); > > SetPageHugetlb(map); > > map++; > > } > > > > In dump_base.c, I changed kernel_page(), referenced_page() and > > unreferenced_page() to test for PageHugetlb() before PageReserved(). > > That makes sense. > > > Since you are looking at identifying hugetlb pages, could any other > > code benefit from a PG_hugetlb flag? > > In the overcommit code we don't actually have the page yet. We're asking > "do we have enough memory available to honour this mmap() invokation when > it later faults in real pages". > > > > ------------------------------------------------------- > This SF.Net email is sponsored by: IBM Linux Tutorials > Free Linux tutorial presented by Daniel Robbins, President and CEO of > GenToo technologies. Learn everything from fundamentals to system > administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click > _______________________________________________ > Lse-tech mailing list > Lse-tech@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/lse-tech
-- Suparna Bhattacharya (suparna@in.ibm.com) Linux Technology Center IBM Software Lab, India
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