Messages in this thread Patch in this message | | | Date | Tue, 13 Jan 2004 11:11:34 +0100 | From | Jan Kasprzak <> | Subject | SOLVED: Performance drop 2.6.0-test7 -> 2.6.1-rc2 |
| |
Jan Kasprzak wrote: : Yesterday I have upgraded the kernel on my FTP server to 2.6.1-rc2 : (from 2.6.0-test7) and today I have found the server struggling under : load average of 40+ and the system was barely usable. The main load on the : server is ProFTPd serving mainly ISO 9660 images using sendfile().
For archives: Andrew Morton suggested to apply the following patch to mm/filemap.c (which in fact reverts part of the patch-2.6.1), and this solved the problem (bigger-than-needed read ahead when doing sendfile() of large files). 2.6.1 with this patch works for me now. Thanks!
-Yenya
diff -puN mm/filemap.c~readahead-partial-backout mm/filemap.c --- 25/mm/filemap.c~readahead-partial-backout 2004-01-09 22:19:32.000000000 -0800 +++ 25-akpm/mm/filemap.c 2004-01-09 22:19:32.000000000 -0800 @@ -587,22 +587,13 @@ void do_generic_mapping_read(struct addr read_actor_t actor) { struct inode *inode = mapping->host; - unsigned long index, offset, last; + unsigned long index, offset; struct page *cached_page; int error; cached_page = NULL; index = *ppos >> PAGE_CACHE_SHIFT; offset = *ppos & ~PAGE_CACHE_MASK; - last = (*ppos + desc->count) >> PAGE_CACHE_SHIFT; - - /* - * Let the readahead logic know upfront about all - * the pages we'll need to satisfy this request - */ - for (; index < last; index++) - page_cache_readahead(mapping, ra, filp, index); - index = *ppos >> PAGE_CACHE_SHIFT; for (;;) { struct page *page; @@ -621,6 +612,7 @@ void do_generic_mapping_read(struct addr } cond_resched(); + page_cache_readahead(mapping, ra, filp, index); nr = nr - offset; find_page: _
-- | Jan "Yenya" Kasprzak <kas at {fi.muni.cz - work | yenya.net - private}> | | GPG: ID 1024/D3498839 Fingerprint 0D99A7FB206605D7 8B35FCDE05B18A5E | | http://www.fi.muni.cz/~kas/ Czech Linux Homepage: http://www.linux.cz/ | | I actually have a lot of admiration and respect for the PATA knowledge | | embedded in drivers/ide. But I would never call it pretty:) -Jeff Garzik | - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |