- 23 3月, 2011 40 次提交
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由 Cesar Eduardo Barros 提交于
scan_swap_map() is a large function (224 lines), with several loops and a complex control flow involving several gotos. Given all that, it is a bit silly that it is marked as inline. The compiler agrees with me: on a x86-64 compile, it did not inline the function. Remove the "inline" and let the compiler decide instead. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Reviewed-by: NPekka Enberg <penberg@kernel.org> Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: NMinchan Kim <minchan.kim@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
The block in sys_swapon which does the final adjustments to the swap_info_struct and to swap_list is the same as the block which re-inserts it again at sys_swapoff on failure of try_to_unuse(). Move this code to a separate function, and use it both in sys_swapon and sys_swapoff. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NPekka Enberg <penberg@kernel.org> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
The block in sys_swapon which does the final adjustments to the swap_info_struct and to swap_list is the same as the block which re-inserts it again at sys_swapoff on failure of try_to_unuse(), except for the order of the operations within the lock. Since the order should not matter, arbitrarily change sys_swapoff to match sys_swapon, in preparation to making both share the same code. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NPekka Enberg <penberg@kernel.org> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
The block in sys_swapon which does the final adjustments to the swap_info_struct and to swap_list is the same as the block which re-inserts it again at sys_swapoff on failure of try_to_unuse(). To be able to make both share the same code, move the printk() call in the middle of it to just after it. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
It still exists within setup_swap_map_and_extents(), but after it nr_good_pages == p->pages. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NPekka Enberg <penberg@kernel.org> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
Since there is no cleanup to do, there is no reason to jump to a label. Return directly instead. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NPekka Enberg <penberg@kernel.org> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
Move the code which parses the bad block list and the extents to a separate function. Only code movement, no functional changes. This change uses the fact that, after the success path, nr_good_pages == p->pages. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NPekka Enberg <penberg@kernel.org> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
The call to swap_cgroup_swapon is in the middle of loading the swap map and extents. As it only does memory allocation and does not depend on the swapfile layout (map/extents), it can be called earlier (or later). Move it to just after the allocation of swap_map, since it is conceptually similar (allocates a map). Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NPekka Enberg <penberg@kernel.org> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
Since there is no cleanup to do, there is no reason to jump to a label. Return directly instead. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
Move the code which parses and checks the swapfile header (except for the bad block list) to a separate function. Only code movement, no functional changes. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
There is no reason I can see to read inode->i_size long before it is needed. Move its read to just before it is needed, to reduce the variable lifetime. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NJesper Juhl <jj@chaosbits.net> Reviewed-by: NPekka Enberg <penberg@kernel.org> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
Since there is no cleanup to do, there is no reason to jump to a label. Return directly instead. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
Move the code which claims the bdev (S_ISBLK) or locks the inode (S_ISREG) to a separate function. Only code movement, no functional changes. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
sys_swapon currently has two error labels, bad_swap and bad_swap_2. bad_swap does the same as bad_swap_2 plus destroy_swap_extents() and swap_cgroup_swapoff(); both are noops in the places where bad_swap_2 is jumped to. With a single extra test for inode (matching the one in the S_ISREG case below), all the error paths in the function can go to bad_swap. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
The only way error is 0 in the cleanup blocks is when the function is returning successfully. In this case, the cleanup blocks were setting S_SWAPFILE in the S_ISREG case. But this is not a cleanup. Move the setting of S_SWAPFILE to just before the "goto out;" to make this more clear. At this point, we do not need to test for inode because it will never be NULL. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
The bdev variable is always equivalent to (S_ISBLK(inode->i_mode) ? p->bdev : NULL), as long as it being set is moved to a bit earlier. Use this fact to remove the bdev variable. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
Move the setting of the error variable nearer the goto in a few places. Avoids calling PTR_ERR() if not IS_ERR() in two places, and makes the error condition more explicit in two other places. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NJesper Juhl <jj@chaosbits.net> Reviewed-by: NPekka Enberg <penberg@kernel.org> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
Since mutex_lock(&inode->i_mutex) is called just after setting inode, did_down is always equivalent to (inode && S_ISREG(inode->i_mode)). Use this fact to remove the did_down variable. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
Now there is nothing which jumps to the cleanup blocks before the name variable is set. There is no need to set it initially to NULL anymore. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NPekka Enberg <penberg@kernel.org> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
Since there is no cleanup to do, there is no reason to jump to a label. Return directly instead. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NPekka Enberg <penberg@kernel.org> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
At this point in sys_swapon, there is nothing to free. Return directly instead of jumping to the cleanup block at the end of the function. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NPekka Enberg <penberg@kernel.org> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
Move the swap_info allocation to its own function. Only code movement, no functional changes. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NPekka Enberg <penberg@kernel.org> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
Within sys_swapon, after the swap_info entry has been allocated, we always have type == p->type and swap_info[type] == p. Use this fact to reduce the dependency on the "type" local variable within the function, as a preparation to move the allocation of the swap_info entry to a separate function. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NPekka Enberg <penberg@kernel.org> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujisu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
Changelogs belong in the git history instead of in the source code. Also, "The swapon system call" is redundant with "SYSCALL_DEFINE2(swapon, ...)". Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NPekka Enberg <penberg@kernel.org> Reviewed-by: NJesper Juhl <jj@chaosbits.net> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> [ Gaah. That's a _historical_ comment. But the patch-series depends on removal ] Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Cesar Eduardo Barros 提交于
This patch series refactors the sys_swapon function. sys_swapon is currently a very large function, with 313 lines (more than 12 25-line screens), which can make it a bit hard to read. This patch series reduces this size by half, by extracting large chunks of related code to new helper functions. One of these chunks of code was nearly identical to the part of sys_swapoff which is used in case of a failure return from try_to_unuse(), so this patch series also makes both share the same code. As a side effect of all this refactoring, the compiled code gets a bit smaller (from v1 of this patch series): text data bss dec hex filename 14012 944 276 15232 3b80 mm/swapfile.o.before 13941 944 276 15161 3b39 mm/swapfile.o.after This patch: Use vzalloc() instead of vmalloc/memset. Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NEric B Munson <emunson@mgebm.net> Reviewed-by: NPekka Enberg <penberg@kernel.org> Reviewed-by: NJesper Juhl <jj@chaosbits.net> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andi Kleen 提交于
Pass __GFP_OTHER_NODE for transparent hugepages NUMA allocations done by the hugepages daemon. This way the low level accounting for local versus remote pages works correctly. Contains improvements from Andrea Arcangeli [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: NAndi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andi Kleen 提交于
Add a new __GFP_OTHER_NODE flag to tell the low level numa statistics in zone_statistics() that an allocation is on behalf of another thread. This way the local and remote counters can be still correct, even when background daemons like khugepaged are changing memory mappings. This only affects the accounting, but I think it's worth doing that right to avoid confusing users. I first tried to just pass down the right node, but this required a lot of changes to pass down this parameter and at least one addition of a 10th argument to a 9 argument function. Using the flag is a lot less intrusive. Open: should be also used for migration? [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: NAndi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrea Arcangeli 提交于
__GFP_NO_KSWAPD allocations are usually very expensive and not mandatory to succeed as they have graceful fallback. Waiting for I/O in those, tends to be overkill in terms of latencies, so we can reduce their latency by disabling sync migrate. Unfortunately, even with async migration it's still possible for the process to be blocked waiting for a request slot (e.g. get_request_wait in the block layer) when ->writepage is called. To prevent __GFP_NO_KSWAPD blocking, this patch prevents ->writepage being called on dirty page cache for asynchronous migration. Addresses https://bugzilla.kernel.org/show_bug.cgi?id=31142 [mel@csn.ul.ie: Avoid writebacks for NFS, retry locked pages, use bool] Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NMel Gorman <mel@csn.ul.ie> Cc: Arthur Marsh <arthur.marsh@internode.on.net> Cc: Clemens Ladisch <cladisch@googlemail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Minchan Kim <minchan.kim@gmail.com> Reported-by: NAlex Villacis Lasso <avillaci@ceibo.fiec.espol.edu.ec> Tested-by: NAlex Villacis Lasso <avillaci@ceibo.fiec.espol.edu.ec> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrea Arcangeli 提交于
compaction_alloc() isolates pages for migration in isolate_migratepages. While it's scanning, IRQs are disabled on the mistaken assumption the scanning should be short. Tests show this to be true for the most part but contention times on the LRU lock can be increased. Before this patch, the IRQ disabled times for a simple test looked like Total sampled time IRQs off (not real total time): 5493 Event shrink_inactive_list..shrink_zone 1596 us count 1 Event shrink_inactive_list..shrink_zone 1530 us count 1 Event shrink_inactive_list..shrink_zone 956 us count 1 Event shrink_inactive_list..shrink_zone 541 us count 1 Event shrink_inactive_list..shrink_zone 531 us count 1 Event split_huge_page..add_to_swap 232 us count 1 Event save_args..call_softirq 36 us count 1 Event save_args..call_softirq 35 us count 2 Event __wake_up..__wake_up 1 us count 1 This patch reduces the worst-case IRQs-disabled latencies by releasing the lock every SWAP_CLUSTER_MAX pages that are scanned and releasing the CPU if necessary. The cost of this is that the processing performing compaction will be slower but IRQs being disabled for too long a time has worse consequences as the following report shows; Total sampled time IRQs off (not real total time): 4367 Event shrink_inactive_list..shrink_zone 881 us count 1 Event shrink_inactive_list..shrink_zone 875 us count 1 Event shrink_inactive_list..shrink_zone 868 us count 1 Event shrink_inactive_list..shrink_zone 555 us count 1 Event split_huge_page..add_to_swap 495 us count 1 Event compact_zone..compact_zone_order 269 us count 1 Event split_huge_page..add_to_swap 266 us count 1 Event shrink_inactive_list..shrink_zone 85 us count 1 Event save_args..call_softirq 36 us count 2 Event __wake_up..__wake_up 1 us count 1 [akpm@linux-foundation.org: simplify with s/unlocked/locked/] Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NMel Gorman <mel@csn.ul.ie> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Arthur Marsh <arthur.marsh@internode.on.net> Cc: Clemens Ladisch <cladisch@googlemail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
compaction_alloc() isolates free pages to be used as migration targets. While its scanning, IRQs are disabled on the mistaken assumption the scanning should be short. Analysis showed that IRQs were in fact being disabled for substantial time. A simple test was run using large anonymous mappings with transparent hugepage support enabled to trigger frequent compactions. A monitor sampled what the worst IRQ-off latencies were and a post-processing tool found the following; Total sampled time IRQs off (not real total time): 22355 Event compaction_alloc..compaction_alloc 8409 us count 1 Event compaction_alloc..compaction_alloc 7341 us count 1 Event compaction_alloc..compaction_alloc 2463 us count 1 Event compaction_alloc..compaction_alloc 2054 us count 1 Event shrink_inactive_list..shrink_zone 1864 us count 1 Event shrink_inactive_list..shrink_zone 88 us count 1 Event save_args..call_softirq 36 us count 1 Event save_args..call_softirq 35 us count 2 Event __make_request..__blk_run_queue 24 us count 1 Event __alloc_pages_nodemask..__alloc_pages_nodemask 6 us count 1 i.e. compaction is disabled IRQs for a prolonged period of time - 8ms in one instance. The full report generated by the tool can be found at http://www.csn.ul.ie/~mel/postings/minfree-20110225/irqsoff-vanilla-micro.report This patch reduces the time IRQs are disabled by simply disabling IRQs at the last possible minute. An updated IRQs-off summary report then looks like; Total sampled time IRQs off (not real total time): 5493 Event shrink_inactive_list..shrink_zone 1596 us count 1 Event shrink_inactive_list..shrink_zone 1530 us count 1 Event shrink_inactive_list..shrink_zone 956 us count 1 Event shrink_inactive_list..shrink_zone 541 us count 1 Event shrink_inactive_list..shrink_zone 531 us count 1 Event split_huge_page..add_to_swap 232 us count 1 Event save_args..call_softirq 36 us count 1 Event save_args..call_softirq 35 us count 2 Event __wake_up..__wake_up 1 us count 1 A full report is again available at http://www.csn.ul.ie/~mel/postings/minfree-20110225/irqsoff-minimiseirq-free-v1r4-micro.report As should be obvious, IRQ disabled latencies due to compaction are almost elimimnated for this particular test. [aarcange@redhat.com: Fix initialisation of isolated] Signed-off-by: NMel Gorman <mel@csn.ul.ie> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujisu.com> Reviewed-by: NMinchan Kim <minchan.kim@gmail.com> Acked-by: NAndrea Arcangeli <aarcange@redhat.com> Cc: Arthur Marsh <arthur.marsh@internode.on.net> Cc: Clemens Ladisch <cladisch@googlemail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
Callers of find_get_pages(), or its wrapper pagevec_lookup() - notably truncate_inode_pages_range() - stop looking further when it returns 0. But if an interrupt comes just after its radix_tree_gang_lookup_slot(), especially if we have preemptible RCU enabled, isn't it conceivable that all 14 pages returned could be removed from the page cache by shrink_page_list(), before find_get_pages() gets to process them? So causing it to return 0 although there may be plenty more pages beyond. Make find_get_pages() and find_get_pages_tag() check for this unlikely case, and restart should it occur; but callers of find_get_pages_contig() have no such expectation, it's okay for that to return 0 early. I have not seen this in practice, just worried by the possibility. Signed-off-by: NHugh Dickins <hughd@google.com> Cc: Nick Piggin <npiggin@kernel.dk> Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Salman Qazi <sqazi@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
The radix_tree_deref_retry() case in find_get_pages() has a strange little excrescence, not seen in the other gang lookups: it looks like the start of an abandoned attempt to guarantee forward progress in a case that cannot arise. ret should always be 0 here: if it isn't, then going back to restart will leak references to pages already gotten. There used to be a comment saying nr_found is necessarily 1 here: that's not quite true, but the radix_tree_deref_retry() case is peculiar to the entry at index 0, when we race with it being moved out of the radix_tree root or back. Remove the worrisome two lines, add a brief comment here and in find_get_pages_contig() and find_get_pages_tag(), and a WARN_ON in find_get_pages() should it ever be seen elsewhere than at 0. Signed-off-by: NHugh Dickins <hughd@google.com> Cc: Nick Piggin <npiggin@kernel.dk> Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Salman Qazi <sqazi@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Petr Holasek 提交于
When the user inserts a negative value into /proc/sys/vm/nr_hugepages it will cause the kernel to allocate as many hugepages as possible and to then update /proc/meminfo to reflect this. This changes the behavior so that the negative input will result in nr_hugepages value being unchanged. Signed-off-by: NPetr Holasek <pholasek@redhat.com> Signed-off-by: NAnton Arapov <anton@redhat.com> Reviewed-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: NDavid Rientjes <rientjes@google.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Acked-by: NEric B Munson <emunson@mgebm.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
When reclaiming for order-0 pages, kswapd requires that all zones be balanced. Each cycle through balance_pgdat() does background ageing on all zones if necessary and applies equal pressure on the inactive zone unless a lot of pages are free already. A "lot of free pages" is defined as a "balance gap" above the high watermark which is currently 7*high_watermark. Historically this was reasonable as min_free_kbytes was small. However, on systems using huge pages, it is recommended that min_free_kbytes is higher and it is tuned with hugeadm --set-recommended-min_free_kbytes. With the introduction of transparent huge page support, this recommended value is also applied. On X86-64 with 4G of memory, min_free_kbytes becomes 67584 so one would expect around 68M of memory to be free. The Normal zone is approximately 35000 pages so under even normal memory pressure such as copying a large file, it gets exhausted quickly. As it is getting exhausted, kswapd applies pressure equally to all zones, including the DMA32 zone. DMA32 is approximately 700,000 pages with a high watermark of around 23,000 pages. In this situation, kswapd will reclaim around (23000*8 where 8 is the high watermark + balance gap of 7 * high watermark) pages or 718M of pages before the zone is ignored. What the user sees is that free memory far higher than it should be. To avoid an excessive number of pages being reclaimed from the larger zones, explicitely defines the "balance gap" to be either 1% of the zone or the low watermark for the zone, whichever is smaller. While kswapd will check all zones to apply pressure, it'll ignore zones that meets the (high_wmark + balance_gap) watermark. To test this, 80G were copied from a partition and the amount of memory being used was recorded. A comparison of a patch and unpatched kernel can be seen at http://www.csn.ul.ie/~mel/postings/minfree-20110222/memory-usage-hydra.ps and shows that kswapd is not reclaiming as much memory with the patch applied. Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NMel Gorman <mel@csn.ul.ie> Acked-by: NRik van Riel <riel@redhat.com> Cc: Shaohua Li <shaohua.li@intel.com> Cc: "Chen, Tim C" <tim.c.chen@intel.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Namhyung Kim 提交于
The 'flags' field is already checked, no need to do it again. Signed-off-by: NNamhyung Kim <namhyung@gmail.com> Cc: Bob Liu <lliubbo@gmail.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Reviewed-by: NMinchan Kim <minchan.kim@gmail.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Dave Hansen 提交于
Now that the mere act of _looking_ at /proc/$pid/smaps will not destroy transparent huge pages, tell how much of the VMA is actually mapped with them. This way, we can make sure that we're getting THPs where we expect to see them. Signed-off-by: NDave Hansen <dave@linux.vnet.ibm.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Acked-by: NDavid Rientjes <rientjes@google.com> Reviewed-by: NEric B Munson <emunson@mgebm.net> Tested-by: NEric B Munson <emunson@mgebm.net> Cc: Michael J Wolf <mjwolf@us.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Dave Hansen 提交于
This adds code to explicitly detect and handle pmd_trans_huge() pmds. It then passes HPAGE_SIZE units in to the smap_pte_entry() function instead of PAGE_SIZE. This means that using /proc/$pid/smaps now will no longer cause THPs to be broken down in to small pages. Signed-off-by: NDave Hansen <dave@linux.vnet.ibm.com> Reviewed-by: NEric B Munson <emunson@mgebm.net> Tested-by: NEric B Munson <emunson@mgebm.net> Acked-by: NAndrea Arcangeli <aarcange@redhat.com> Acked-by: NDavid Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Michael J Wolf <mjwolf@us.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Dave Hansen 提交于
Add an argument to the new smaps_pte_entry() function to let it account in things other than PAGE_SIZE units. I changed all of the PAGE_SIZE sites, even though not all of them can be reached for transparent huge pages, just so this will continue to work without changes as THPs are improved. Signed-off-by: NDave Hansen <dave@linux.vnet.ibm.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NDavid Rientjes <rientjes@google.com> Reviewed-by: NEric B Munson <emunson@mgebm.net> Tested-by: NEric B Munson <emunson@mgebm.net> Cc: Michael J Wolf <mjwolf@us.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Dave Hansen 提交于
We will use smaps_pte_entry() in a moment to handle both small and transparent large pages. But, we must break it out of smaps_pte_range() first. Signed-off-by: NDave Hansen <dave@linux.vnet.ibm.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NDavid Rientjes <rientjes@google.com> Reviewed-by: NEric B Munson <emunson@mgebm.net> Tested-by: NEric B Munson <emunson@mgebm.net> Cc: Michael J Wolf <mjwolf@us.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Dave Hansen 提交于
Right now, if a mm_walk has either ->pte_entry or ->pmd_entry set, it will unconditionally split any transparent huge pages it runs in to. In practice, that means that anyone doing a cat /proc/$pid/smaps will unconditionally break down every huge page in the process and depend on khugepaged to re-collapse it later. This is fairly suboptimal. This patch changes that behavior. It teaches each ->pmd_entry handler (there are five) that they must break down the THPs themselves. Also, the _generic_ code will never break down a THP unless a ->pte_entry handler is actually set. This means that the ->pmd_entry handlers can now choose to deal with THPs without breaking them down. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: NDave Hansen <dave@linux.vnet.ibm.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Acked-by: NDavid Rientjes <rientjes@google.com> Reviewed-by: NEric B Munson <emunson@mgebm.net> Tested-by: NEric B Munson <emunson@mgebm.net> Cc: Michael J Wolf <mjwolf@us.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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