Helding the Kernel lock while doing IO???

["Juan J. Quintela" <quintela@fi.udc.es>]

Hi
        In the function m/memory.c()::do_swap_page():

		lock_kernel();
		swapin_readahead(entry);
		page = read_swap_cache(entry);
		unlock_kernel();

read_swap_cache is called synchronously, then we can have to wait
until we read the page to liberate the lock kernel.  It is intended?
I am losing some detail?

I have  changed that in the two places that happened.

Thanks in advance for any response.

Later, Juan.

diff -u -urN --exclude=CVS --exclude=*~ --exclude=.#* --exclude=TAGS pre7-6/ipc/shm.c testing2/ipc/shm.c
--- pre7-6/ipc/shm.c	Fri May  5 23:58:56 2000
+++ testing2/ipc/shm.c	Sat May  6 02:39:17 2000
@@ -1379,10 +1379,11 @@
 			if (!page) {
 				lock_kernel();
 				swapin_readahead(entry);
-				page = read_swap_cache(entry);
+				page = read_swap_cache_async(entry, 0);
 				unlock_kernel();
 				if (!page)
 					goto oom;
+                                wait_on_page(page);
 			}
 			delete_from_swap_cache(page);
 			page = replace_with_highmem(page);
diff -u -urN --exclude=CVS --exclude=*~ --exclude=.#* --exclude=TAGS pre7-6/mm/memory.c testing2/mm/memory.c
--- pre7-6/mm/memory.c	Fri May  5 23:58:56 2000
+++ testing2/mm/memory.c	Sat May  6 02:02:53 2000
@@ -1038,11 +1038,10 @@
 	if (!page) {
 		lock_kernel();
 		swapin_readahead(entry);
-		page = read_swap_cache(entry);
+		page = read_swap_cache_async(entry, 0);
 		unlock_kernel();
 		if (!page)
 			return -1;
-
 		flush_page_to_ram(page);
 		flush_icache_page(vma, page);
 	}


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are different -- Larry McVoy
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