From 8e30f272a93ec9c1d5c305c5040dfaebc880499d Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Sun, 1 May 2005 08:58:36 -0700 Subject: [PATCH] mm: pcp use non powers of 2 for batch size Jack Steiner reported this to have fixed his problem (bad colouring): "The patches fix both problems that I found - bad coloring & excessive pages in pagesets." In most workloads this is not likely to be such a pronounced problem, however it should help corner cases. And avoiding powers of 2 in these types of memory operations is always a good idea. Signed-off-by: Nick Piggin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index c73dbbc1cd8f..08e8627361a0 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1671,6 +1671,18 @@ static void __init free_area_init_core(struct pglist_data *pgdat, if (batch < 1) batch = 1; + /* + * Clamp the batch to a 2^n - 1 value. Having a power + * of 2 value was found to be more likely to have + * suboptimal cache aliasing properties in some cases. + * + * For example if 2 tasks are alternately allocating + * batches of pages, one task can end up with a lot + * of pages of one half of the possible page colors + * and the other with pages of the other colors. + */ + batch = (1 << fls(batch + batch/2)) - 1; + for (cpu = 0; cpu < NR_CPUS; cpu++) { struct per_cpu_pages *pcp; -- cgit v1.2.3 From b84a35be0285229b0a8a5e2e04d79360c5b75562 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Sun, 1 May 2005 08:58:36 -0700 Subject: [PATCH] mempool: NOMEMALLOC and NORETRY Mempools have 2 problems. The first is that mempool_alloc can possibly get stuck in __alloc_pages when they should opt to fail, and take an element from their reserved pool. The second is that it will happily eat emergency PF_MEMALLOC reserves instead of going to their reserved pools. Fix the first by passing __GFP_NORETRY in the allocation calls in mempool_alloc. Fix the second by introducing a __GFP_MEMPOOL flag which directs the page allocator not to allocate from the reserve pool. Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 08e8627361a0..04a35b3d3262 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -799,14 +799,18 @@ __alloc_pages(unsigned int __nocast gfp_mask, unsigned int order, } /* This allocation should allow future memory freeing. */ - if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE))) && !in_interrupt()) { - /* go through the zonelist yet again, ignoring mins */ - for (i = 0; (z = zones[i]) != NULL; i++) { - if (!cpuset_zone_allowed(z)) - continue; - page = buffered_rmqueue(z, order, gfp_mask); - if (page) - goto got_pg; + + if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE))) + && !in_interrupt()) { + if (!(gfp_mask & __GFP_NOMEMALLOC)) { + /* go through the zonelist yet again, ignoring mins */ + for (i = 0; (z = zones[i]) != NULL; i++) { + if (!cpuset_zone_allowed(z)) + continue; + page = buffered_rmqueue(z, order, gfp_mask); + if (page) + goto got_pg; + } } goto nopage; } -- cgit v1.2.3 From edfbe2b0038723e5699ab22695ccd62b5542a5c1 Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Sun, 1 May 2005 08:58:37 -0700 Subject: [PATCH] count bounce buffer pages in vmstat This is a patch for counting the number of pages for bounce buffers. It's shown in /proc/vmstat. Currently, the number of bounce pages are not counted anywhere. So, if there are many bounce pages, it seems that there are leaked pages. And it's difficult for a user to imagine the usage of bounce pages. So, it's meaningful to show # of bouce pages. Signed-off-by: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 1 + 1 file changed, 1 insertion(+) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 04a35b3d3262..80ce7f2104df 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1897,6 +1897,7 @@ static char *vmstat_text[] = { "allocstall", "pgrotated", + "nr_bounce", }; static void *vmstat_start(struct seq_file *m, loff_t *pos) -- cgit v1.2.3 From 4dc3b16ba18c0f967ad100c52fa65b01a4f76ff0 Mon Sep 17 00:00:00 2001 From: Pavel Pisa Date: Sun, 1 May 2005 08:59:25 -0700 Subject: [PATCH] DocBook: changes and extensions to the kernel documentation I have recompiled Linux kernel 2.6.11.5 documentation for me and our university students again. The documentation could be extended for more sources which are equipped by structured comments for recent 2.6 kernels. I have tried to proceed with that task. I have done that more times from 2.6.0 time and it gets boring to do same changes again and again. Linux kernel compiles after changes for i386 and ARM targets. I have added references to some more files into kernel-api book, I have added some section names as well. So please, check that changes do not break something and that categories are not too much skewed. I have changed kernel-doc to accept "fastcall" and "asmlinkage" words reserved by kernel convention. Most of the other changes are modifications in the comments to make kernel-doc happy, accept some parameters description and do not bail out on errors. Changed to @pid in the description, moved some #ifdef before comments to correct function to comments bindings, etc. You can see result of the modified documentation build at http://cmp.felk.cvut.cz/~pisa/linux/lkdb-2.6.11.tar.gz Some more sources are ready to be included into kernel-doc generated documentation. Sources has been added into kernel-api for now. Some more section names added and probably some more chaos introduced as result of quick cleanup work. Signed-off-by: Pavel Pisa Signed-off-by: Martin Waitz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 80ce7f2104df..fc1b1064c505 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1355,8 +1355,7 @@ static int __init build_zonelists_node(pg_data_t *pgdat, struct zonelist *zoneli #define MAX_NODE_LOAD (num_online_nodes()) static int __initdata node_load[MAX_NUMNODES]; /** - * find_next_best_node - find the next node that should appear in a given - * node's fallback list + * find_next_best_node - find the next node that should appear in a given node's fallback list * @node: node whose fallback list we're appending * @used_node_mask: nodemask_t of already used nodes * -- cgit v1.2.3