Hi Linus, Daniel,
the (trivial) patch below fixes the drop-behind call in
generic_file_write to *only* do drop-behind if we've
written "past the end" of the page.
This way we have a better chance of still having partially
written pages in memory when we write to them again (eg. for
TUX logfiles). Not only will this speed up non page-aligned
writes on loaded systems, it'll also give slower writes a
small advantage over fast writes (which will skip page boundaries
more often).
Linus, Alan, could you please apply this patch in your next
2.4.0-test kernel ?
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 majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sun Dec 31 2000 - 21:00:11 EST