[PATCH] generic_file_map drop-behind fix

2000-12-21 Thread Rik van Riel

Hi Ingo,

the attached patch (against 2.4.0-test12-pre3) should fix the
problem where generic_file_write() causes a page to be moved
to the inactive list when the program is still writing to it.

Does this patch fix the web benching bottleneck in tux2 ? ;)

regards,

Rik
--
Hollywood goes for world dumbination,
Trailer at 11.

http://www.surriel.com/
http://www.conectiva.com/   http://distro.conectiva.com.br/


--- linux-2.4.0-test12-pre3/mm/filemap.c.orig   2000/12/21 18:20:17
+++ linux/mm/filemap.c  2000/12/21 21:31:39
@@ -2436,7 +2436,7 @@
}
 
while (count) {
-   unsigned long bytes, index, offset;
+   unsigned long bytes, index, offset, partial = 0;
char *kaddr;
 
/*
@@ -2446,8 +2446,10 @@
offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
index = pos >> PAGE_CACHE_SHIFT;
bytes = PAGE_CACHE_SIZE - offset;
-   if (bytes > count)
+   if (bytes > count) {
bytes = count;
+   partial = 1;
+   }
 
status = -ENOMEM;   /* we'll assign it later anyway */
page = __grab_cache_page(mapping, index, _page);
@@ -2478,9 +2480,17 @@
buf += status;
}
 unlock:
-   /* Mark it unlocked again and drop the page.. */
+   /*
+* Mark it unlocked again and release the page.
+* In order to prevent large (fast) file writes
+* from causing too much memory pressure we move
+* completely written pages to the inactive list.
+* We do, however, try to keep the pages that may
+* still be written to (ie. partially written pages).
+*/
UnlockPage(page);
-   deactivate_page(page);
+   if (!partial)
+   deactivate_page(page);
page_cache_release(page);
 
if (status < 0)


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[PATCH] generic_file_map drop-behind fix

2000-12-21 Thread Rik van Riel

Hi Ingo,

the attached patch (against 2.4.0-test12-pre3) should fix the
problem where generic_file_write() causes a page to be moved
to the inactive list when the program is still writing to it.

Does this patch fix the web benching bottleneck in tux2 ? ;)

regards,

Rik
--
Hollywood goes for world dumbination,
Trailer at 11.

http://www.surriel.com/
http://www.conectiva.com/   http://distro.conectiva.com.br/


--- linux-2.4.0-test12-pre3/mm/filemap.c.orig   2000/12/21 18:20:17
+++ linux/mm/filemap.c  2000/12/21 21:31:39
@@ -2436,7 +2436,7 @@
}
 
while (count) {
-   unsigned long bytes, index, offset;
+   unsigned long bytes, index, offset, partial = 0;
char *kaddr;
 
/*
@@ -2446,8 +2446,10 @@
offset = (pos  (PAGE_CACHE_SIZE -1)); /* Within page */
index = pos  PAGE_CACHE_SHIFT;
bytes = PAGE_CACHE_SIZE - offset;
-   if (bytes  count)
+   if (bytes  count) {
bytes = count;
+   partial = 1;
+   }
 
status = -ENOMEM;   /* we'll assign it later anyway */
page = __grab_cache_page(mapping, index, cached_page);
@@ -2478,9 +2480,17 @@
buf += status;
}
 unlock:
-   /* Mark it unlocked again and drop the page.. */
+   /*
+* Mark it unlocked again and release the page.
+* In order to prevent large (fast) file writes
+* from causing too much memory pressure we move
+* completely written pages to the inactive list.
+* We do, however, try to keep the pages that may
+* still be written to (ie. partially written pages).
+*/
UnlockPage(page);
-   deactivate_page(page);
+   if (!partial)
+   deactivate_page(page);
page_cache_release(page);
 
if (status  0)


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
Please read the FAQ at http://www.tux.org/lkml/