Messages in this thread | | | Date | Sat, 06 Sep 2008 21:54:05 -0400 | From | Oren Laadan <> | Subject | Re: [RFC v3][PATCH 4/9] Memory management (dump) |
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Dave Hansen wrote: > On Thu, 2008-09-04 at 04:03 -0400, Oren Laadan wrote: >> +/* free a chain of page-arrays */ >> +void cr_pgarr_free(struct cr_ctx *ctx) >> +{ >> + struct cr_pgarr *pgarr, *pgnxt; >> + >> + for (pgarr = ctx->pgarr; pgarr; pgarr = pgnxt) { >> + _cr_pgarr_release(ctx, pgarr); >> + free_pages((unsigned long) ctx->pgarr->addrs, CR_PGARR_ORDER); >> + free_pages((unsigned long) ctx->pgarr->pages, CR_PGARR_ORDER); >> + pgnxt = pgarr->next; >> + kfree(pgarr); >> + } >> +} > > What we effectively have here is: > > void *addrs[CR_PGARR_TOTAL]; > void *pages[CR_PGARR_TOTAL]; > > right? > > Would any of this get simpler if we just had: > > struct cr_page { > struct page *page; > unsigned long vaddr; > }; > > struct cr_pgarr { > struct cr_page *cr_pages; > struct cr_pgarr *next; > unsigned short nleft; > unsigned short nused; > };
The reason I use separate arrays instead of an array of tuples is that the logic is to write all vaddr at once - simply by dumping the array of vaddrs.
> > Also, we do have lots of linked list implementations in the kernel. > They do lots of fun stuff like poisoning and checking for > initialization. We should use them instead of rolling our own. It lets > us do other fun stuff like list_for_each(). > > Also, just looking at this structure 'nleft' and 'nused' sound a bit > redundant. I know from looking at the code that this is how many have > been filled and read back at restore time, but that is not very obvious > looking at the structure. I think we can do a bit better in the > structure itself. > > The length of the arrays is fixed at compile-time, right? Should we > just make that explicit as well?
The length of the array may be tunable, or even adaptive (e.g. based on statistics from recent checkpoints), in the future.
Oren.
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